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1.
Nature ; 608(7921): 62-68, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35922499

RESUMO

Additive manufacturing produces net-shaped components layer by layer for engineering applications1-7. The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling2,6, which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility3. Here we use L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi2.1 that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large uniform elongation of about 14 per cent, which surpasses those of other state-of-the-art additively manufactured metal alloys. The high yield strength stems from the strong strengthening effects of the dual-phase structures that consist of alternating face-centred cubic and body-centred cubic nanolamellae; the body-centred cubic nanolamellae exhibit higher strengths and higher hardening rates than the face-centred cubic nanolamellae. The large tensile ductility arises owing to the high work-hardening capability of the as-printed hierarchical microstructures in the form of dual-phase nanolamellae embedded in microscale eutectic colonies, which have nearly random orientations to promote isotropic mechanical properties. The mechanistic insights into the deformation behaviour of additively manufactured HEAs have broad implications for the development of hierarchical, dual- and multi-phase, nanostructured alloys with exceptional mechanical properties.

2.
EMBO J ; 41(16): e110636, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35638332

RESUMO

Activation of the T-cell antigen receptor (TCR)-CD3 complex is critical to induce the anti-tumor response of CD8+ T cells. Here, we found that disulfiram (DSF), an FDA-approved drug previously used to treat alcohol dependency, directly activates TCR signaling. Mechanistically, DSF covalently binds to Cys20/Cys23 residues of lymphocyte-specific protein tyrosine kinase (LCK) and enhances its tyrosine 394 phosphorylation, thereby promoting LCK kinase activity and boosting effector T cell function, interleukin-2 production, metabolic reprogramming, and proliferation. Furthermore, our in vivo data revealed that DSF promotes anti-tumor immunity against both melanoma and colon cancer in mice by activating CD8+ T cells, and this effect was enhanced by anti-PD-1 co-treatment. We conclude that DSF directly activates LCK-mediated TCR signaling to induce strong anti-tumor immunity, providing novel molecular insights into the therapeutic effect of DSF on cancer.


Assuntos
Dissulfiram , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Animais , Linfócitos T CD8-Positivos , Dissulfiram/farmacologia , Ativação Linfocitária , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Camundongos , Fosforilação , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais
3.
Plant J ; 120(1): 29-44, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39213173

RESUMO

Erianin, crepidatin, and chrysotobibenzyl are typical medicinal polymethoxylated bibenzyls (PMBs) that are commercially produced in Dendrobium species. PMBs' chemo-diversity is mediated by the manifold combinations of O-methylation and hydroxylation in a definite order, which remains unsolved. To unequivocally elucidate the methylation mechanism of PMBs, 15 possible intermediates in the biosynthetic pathway of PMBs were chemically synthesized. DcOMT1-5 were highly expressed in tissues where PMBs were biosynthesized, and their expression patterns were well-correlated with the accumulation profiles of PMBs. Moreover, cell-free orthogonal tests based on the synthesized intermediates further confirmed that DcOMT1-5 exhibited distinct substrate preferences and displayed hydroxyl-group regiospecificity during the sequential methylation process. The stepwise methylation of PMBs was discovered from SAM to dihydro-piceatannol (P) in the following order: P → 3-MeP → 4-OH-3-MeP → 4-OH-3,5-diMeP → 3,3'(4'),5-triMeP → 3,4,4',5-tetraMeP (erianin) or 3,3',4,5-tetraMeP (crepidatin) → 3,3',4,4',5-pentaMeP (chrysotobibenzyl). Furthermore, the regioselectivities of DcOMTs were investigated by ligand docking analyses which corresponded precisely with the catalytic activities. In summary, the findings shed light on the sequential catalytic mechanisms of PMB biosynthesis and provide a comprehensive PMB biosynthetic network in D. catenatum. The knowledge gained from this study may also contribute to the development of plant-based medicinal applications and the production of high-value PMBs.


Assuntos
Bibenzilas , Dendrobium , Metiltransferases , Dendrobium/metabolismo , Dendrobium/enzimologia , Dendrobium/genética , Bibenzilas/metabolismo , Metilação , Metiltransferases/metabolismo , Metiltransferases/genética , Metiltransferases/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Vias Biossintéticas , Regulação da Expressão Gênica de Plantas , Especificidade por Substrato
4.
Nature ; 574(7777): 223-227, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31597974

RESUMO

High-entropy alloys are a class of materials that contain five or more elements in near-equiatomic proportions1,2. Their unconventional compositions and chemical structures hold promise for achieving unprecedented combinations of mechanical properties3-8. Rational design of such alloys hinges on an understanding of the composition-structure-property relationships in a near-infinite compositional space9,10. Here we use atomic-resolution chemical mapping to reveal the element distribution of the widely studied face-centred cubic CrMnFeCoNi Cantor alloy2 and of a new face-centred cubic alloy, CrFeCoNiPd. In the Cantor alloy, the distribution of the five constituent elements is relatively random and uniform. By contrast, in the CrFeCoNiPd alloy, in which the palladium atoms have a markedly different atomic size and electronegativity from the other elements, the homogeneity decreases considerably; all five elements tend to show greater aggregation, with a wavelength of incipient concentration waves11,12 as small as 1 to 3 nanometres. The resulting nanoscale alternating tensile and compressive strain fields lead to considerable resistance to dislocation glide. In situ transmission electron microscopy during straining experiments reveals massive dislocation cross-slip from the early stage of plastic deformation, resulting in strong dislocation interactions between multiple slip systems. These deformation mechanisms in the CrFeCoNiPd alloy, which differ markedly from those in the Cantor alloy and other face-centred cubic high-entropy alloys, are promoted by pronounced fluctuations in composition and an increase in stacking-fault energy, leading to higher yield strength without compromising strain hardening and tensile ductility. Mapping atomic-scale element distributions opens opportunities for understanding chemical structures and thus providing a basis for tuning composition and atomic configurations to obtain outstanding mechanical properties.

5.
Cereb Cortex ; 34(10)2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39441024

RESUMO

We aimed to longitudinally examine the relationship between depression and cognitive function and investigate the mediating effects of imaging indicators in this relationship. 2,251 subjects with longitudinal assessment of geriatric depression scale, Mini-Mental State Examination, Montreal Cognitive Assessment, Clinical Dementia Rating-Sum of Boxes (CDRSB), Alzheimer's Disease Assessment Scale11, Alzheimer's Disease Assessment Scale13 and imaging of 3DT1, diffusion tensor imaging, fluid-attenuated inversion recovery, arterial spin labeling, fluorodeoxyglucose positron emission tomography, 18F-AV45-PET, and 18F-AV1451-PET were included from the Alzheimer's Disease Neuroimaging Initiative database. The multivariate mixed-effects models were employed to analyze the correlation between geriatric depression scale scores, cognitive function, and imaging indicators. The sgmediation software package was utilized to analyze the mediating effects of imaging indicators. The geriatric depression scale was negatively correlated with Mini-Mental State Examination and Montreal Cognitive Assessment, and positively correlated with CDRSB, Alzheimer's Disease Assessment Scale11, and Alzheimer's Disease Assessment Scale13 when the subjects were not grouped. The geriatric depression scale was negatively correlated with Montreal Cognitive Assessment and positively correlated with Alzheimer's Disease Assessment Scal13 in groups with baseline diagnosis of early mild cognitive impairment and late mild cognitive impairment. Furthermore, depression was associated with regional imaging indicators, while cognitive function was linked to broad imaging indicators. Some of these indicators were related to both depression and cognitive function, playing a mediating role in their relationship. Depression was related to cognitive function, especially in subjects with mild cognitive impairment. Some imaging indicators may represent the underlying basis for the association between depression and cognitive function.


Assuntos
Doença de Alzheimer , Biomarcadores , Cognição , Disfunção Cognitiva , Depressão , Neuroimagem , Tomografia por Emissão de Pósitrons , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/psicologia , Doença de Alzheimer/complicações , Idoso , Feminino , Masculino , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/psicologia , Depressão/diagnóstico por imagem , Depressão/psicologia , Neuroimagem/métodos , Estudos Longitudinais , Cognição/fisiologia , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Testes Neuropsicológicos
6.
Proc Natl Acad Sci U S A ; 119(3)2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35012985

RESUMO

Materials containing heterogeneous nanostructures hold great promise for achieving superior mechanical properties. However, the strengthening effect due to plastically inhomogeneous deformation in heterogeneous nanostructures has not been clearly understood. Here, we investigate a prototypical heterogeneous nanostructured material of gradient nanotwinned (GNT) Cu to unravel the origin of its extra strength arising from gradient nanotwin structures relative to uniform nanotwin counterparts. We measure the back and effective stresses of GNT Cu with different nanotwin thickness gradients and compare them with those of homogeneous nanotwinned Cu with different uniform nanotwin thicknesses. We find that the extra strength of GNT Cu is caused predominantly by the extra back stress resulting from nanotwin thickness gradient, while the effective stress is almost independent of the gradient structures. The combined experiment and strain gradient plasticity modeling show that an increasing structural gradient in GNT Cu produces an increasing plastic strain gradient, thereby raising the extra back stress. The plastic strain gradient is accommodated by the accumulation of geometrically necessary dislocations inside an unusual type of heterogeneous dislocation structure in the form of bundles of concentrated dislocations. Such a heterogeneous dislocation structure produces microscale internal stresses leading to the extra back stress in GNT Cu. Altogether, this work establishes a fundamental connection between the gradient structure and extra strength in GNT Cu through the mechanistic linkages of plastic strain gradient, heterogeneous dislocation structure, microscale internal stress, and extra back stress. Broadly, this work exemplifies a general approach to unraveling the strengthening mechanisms in heterogeneous nanostructured materials.

7.
Am J Physiol Cell Physiol ; 327(4): C994-C1011, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39183639

RESUMO

The increasing prevalence of obesity-related glomerulopathy (ORG) poses a significant threat to public health. Sodium-glucose cotransporter-2 (SGLT2) inhibitors effectively reduce body weight and total fat mass in individuals with obesity and halt the progression of ORG. However, the underlying mechanisms of their reno-protective effects in ORG remain unclear. We established a high-fat diet-induced ORG model using C57BL/6J mice, which were divided into three groups: normal chow diet (NCD group), high-fat diet (HFD) mice treated with placebo (ORG group), and HFD mice treated with empagliflozin (EMPA group). We conducted 16S ribosomal RNA gene sequencing of feces and analyzed metabolites from kidney, feces, liver, and serum samples. ORG mice showed increased urinary albumin creatinine ratio, cholesterol, triglyceride levels, and glomerular diameter compared with NCD mice (all P < 0.05). EMPA treatment significantly alleviated these parameters (all P < 0.05). Multitissue metabolomics analysis revealed lipid metabolic reprogramming in ORG mice, which was significantly altered by EMPA treatment. MetOrigin analysis showed a close association between EMPA-related lipid metabolic pathways and gut microbiota alterations, characterized by reduced abundances of Firmicutes and Desulfovibrio and increased abundance of Akkermansia (all P < 0.05). The metabolic homeostasis of ORG mice, especially in lipid metabolism, was disrupted and closely associated with gut microbiota alterations, contributing to the progression of ORG. EMPA treatment improved kidney function and morphology by regulating lipid metabolism through the gut-kidney axis, highlighting a novel therapeutic approach for ORG. NEW & NOTEWORTHY Our study uncovered that empagliflozin (EMPA) potentially protects renal function and morphology in obesity-related glomerulopathy (ORG) mice by regulating the gut-kidney axis. EMPA's reno-protective effects in ORG mice are associated with the lipid metabolism, especially in glycerophospholipid metabolism and the pantothenate/CoA synthesis pathways. EMPA's modulation of gut microbiota appears to be pivotal in suppressing glycerol 3-phosphate and CoA synthesis. The insights into gut microbiota-host metabolic interactions offer a novel therapeutic approach for ORG.


Assuntos
Compostos Benzidrílicos , Dieta Hiperlipídica , Microbioma Gastrointestinal , Glucosídeos , Rim , Camundongos Endogâmicos C57BL , Obesidade , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Compostos Benzidrílicos/farmacologia , Obesidade/metabolismo , Obesidade/tratamento farmacológico , Camundongos , Masculino , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Nefropatias/metabolismo , Nefropatias/prevenção & controle , Nefropatias/etiologia , Nefropatias/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Modelos Animais de Doenças
8.
J Physiol ; 602(6): 1175-1197, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38431908

RESUMO

Non-invasive transcranial direct-current stimulation (tDCS) is a safe ischaemic stroke therapy. Cathodal bilateral tDCS (BtDCS) is a modified tDCS approach established by us recently. Because selenium (Se) plays a crucial role in cerebral ischaemic injury, we investigated whether cathodal BtDCS conferred neuroprotection via regulating Se-dependent signalling in rat cerebral ischaemia-reperfusion (I/R) injury. We first showed that the levels of Se and its transport protein selenoprotein P (SEPP1) were reduced in the rat cortical penumbra following I/R, whereas cathodal BtDCS prevented the reduction of Se and SEPP1. Interestingly, direct-current stimulation (DCS) increased SEPP1 level in cultured astrocytes subjected to oxygen-glucose deprivation reoxygenation (OGD/R) but had no effect on SEPP1 level in OGD/R-insulted neurons, indicating that DCS may increase Se in ischaemic neurons by enhancing the synthesis and secretion of SEPP1 in astrocytes. We then revealed that DCS reduced the number of injured mitochondria in OGD/R-insulted neurons cocultured with astrocytes. DCS and BtDCS prevented the reduction of the mitochondrial quality-control signalling, vesicle-associated membrane protein 2 (VAMP2) and syntaxin-4 (STX4), in OGD/R-insulted neurons cocultured with astrocytes and the ischaemic brain respectively. Under the same experimental conditions, downregulation of SEPP1 blocked DCS- and BtDCS-induced upregulation of VAMP2 and STX4. Finally, we demonstrated that cathodal BtDCS increased Se to reduce infract volume following I/R. Together, the present study uncovered a molecular mechanism by which cathodal BtDCS confers neuroprotection through increasing SEPP1 in astrocytes and subsequent upregulation of SEPP1/VAMP2/STX4 signalling in ischaemic neurons after rat cerebral I/R injury. KEY POINTS: Cathodal bilateral transcranial direct-current stimulation (BtDCS) prevents the reduction of selenium (Se) and selenoprotein P in the ischaemic penumbra. Se plays a crucial role in cerebral ischaemia injury. Direct-current stimulation reduces mitochondria injury and blocks the reduction of vesicle-associated membrane protein 2 (VAMP2) and syntaxin-4 (STX4) in oxygen-glucose deprivation reoxygenation-insulted neurons following coculturing with astrocytes. Cathodal BtDCS regulates Se/VAMP2/STX4 signalling to confer neuroprotection after ischaemia.


Assuntos
Isquemia Encefálica , Traumatismo por Reperfusão , Selênio , Acidente Vascular Cerebral , Estimulação Transcraniana por Corrente Contínua , Ratos , Animais , Isquemia Encefálica/terapia , Isquemia Encefálica/metabolismo , Neuroproteção/fisiologia , Proteína 2 Associada à Membrana da Vesícula , Selenoproteína P , Oxigênio/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/metabolismo , Glucose/metabolismo , Proteínas Qa-SNARE
9.
Neurobiol Dis ; 190: 106375, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38092269

RESUMO

Patients with chronic pain often experience memory impairment, but the underlying mechanisms remain elusive. The myelin sheath is crucial for rapid and accurate action potential conduction, playing a pivotal role in the development of cognitive abilities in the central nervous system. The study reveals that myelin degradation occurs in the hippocampus of chronic constriction injury (CCI) mice, which display both chronic pain and memory impairment. Using fiber photometry, we observed diminished task-related neuronal activity in the hippocampus of CCI mice. Interestingly, the repeated administration with clemastine, which promotes myelination, counteracts the CCI-induced myelin loss and reduced neuronal activity. Notably, clemastine specifically ameliorates the impaired memory without affecting chronic pain in CCI mice. Overall, our findings highlight the significant role of myelin abnormalities in CCI-induced memory impairment, suggesting a potential therapeutic approach for treating memory impairments associated with neuropathic pain.


Assuntos
Dor Crônica , Clemastina , Humanos , Animais , Camundongos , Clemastina/metabolismo , Dor Crônica/tratamento farmacológico , Dor Crônica/metabolismo , Bainha de Mielina/metabolismo , Sistema Nervoso Central , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Hipocampo/metabolismo
10.
BMC Med ; 22(1): 224, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831391

RESUMO

BACKGROUND: Type 2 diabetes is associated with a variety of complications, including micro- and macrovascular complications, neurological manifestations and poor wound healing. Adhering to a Mediterranean Diet (MED) is generally considered an effective intervention in individuals at risk for type 2 diabetes mellitus (T2DM). However, little is known about its effect with respect to the different specific manifestations of T2DM. This prompted us to explore the effect of MED on the three most significant microvascular complications of T2DM: diabetic retinopathy (DR), diabetic kidney disease (DKD), and vascular diabetic neuropathies (DN). METHODS: We examined the association between the MED and the incidence of these microvascular complications in a prospective cohort of 33,441 participants with hyperglycemia free of microvascular complications at baseline, identified in the UK Biobank. For each individual, we calculated the Alternate Mediterranean Diet (AMED) score, which yields a semi-continuous measure of the extent to which an individual's diet can be considered as MED. We used Cox proportional hazard models to analyze hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics, lifestyle factors, medical histories and cardiovascular risk factors. RESULTS: Over a median of 12.3 years of follow-up, 3,392 cases of microvascular complications occurred, including 1,084 cases of diabetic retinopathy (DR), 2,184 cases of diabetic kidney disease (DKD), and 632 cases of diabetic neuropathies (DN), with some patients having 2 or 3 microvascular complications simultaneously. After adjusting for confounders, we observed that higher AMED scores offer protection against DKD among participants with hyperglycemia (comparing the highest AMED scores to the lowest yielded an HR of 0.79 [95% CIs: 0.67, 0.94]). Additionally, the protective effect of AMED against DKD was more evident in the hyperglycemic participants with T2DM (HR, 0.64; 95% CI: 0.50, 0.83). No such effect, however, was seen for DR or DN. CONCLUSIONS: In this prospective cohort study, we have demonstrated that higher adherence to a MED is associated with a reduced risk of DKD among individuals with hyperglycemia. Our study emphasizes the necessity for continued research focusing on the benefits of the MED. Such efforts including the ongoing clinical trial will offer further insights into the role of MED in the clinical management of DKD.


Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Dieta Mediterrânea , Hiperglicemia , Humanos , Estudos Prospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Nefropatias Diabéticas/dietoterapia , Nefropatias Diabéticas/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/dietoterapia , Idoso , Hiperglicemia/epidemiologia , Hiperglicemia/complicações , Adulto , Reino Unido/epidemiologia , Retinopatia Diabética/epidemiologia , Retinopatia Diabética/dietoterapia , Incidência , Neuropatias Diabéticas/epidemiologia , Neuropatias Diabéticas/dietoterapia , Fatores de Risco
11.
Small ; 20(40): e2402654, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38830339

RESUMO

Constructing a built-in interfacial electric field (BIEF) is an effective approach to enhance the electrocatalysts performance, but it has been rarely demonstrated for electrochemical carbon dioxide reduction reaction (CO2RR) to date. Herein, for the first time, SnO2/LaOCl nanofibers (NFs) with BIEF is created by electrospinning, exhibiting a high Faradaic efficiency (FE) of 100% C1 product (CO and HCOOH) at -0.9--1.1 V versus reversible hydrogen electrode (RHE) and a maximum FEHCOOH of 90.1% at -1.2 VRHE in H-cell, superior to the commercial SnO2 nanoparticles (NPs) and LaOCl NFs. SnO2/LaOCl NFs also exhibit outstanding stability, maintaining negligible activity degradation even after 10 h of electrolysis. Moreover, their current density and FEHCOOH are almost 400 mA cm-2 at -2.31 V and 83.4% in flow-cell. The satisfactory CO2RR performance of SnO2/LaOCl NFs with BIEF can be ascribed to tight interface of coupling SnO2 NPs and LaOCl NFs, which can induce charge redistribution, rich active sites, enhanced CO2 adsorption, as well as optimized Gibbs free energy of *OCHO. The work reveals that the BIEF will trigger interfacial accumulation and stability enhancement effects in promoting CO2RR activity and stability of SnO2-based materials, providing a novel approach to develop stable and efficient CO2RR electrocatalysts.

12.
J Transl Med ; 22(1): 901, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39367456

RESUMO

BACKGROUND: Several studies have reported that combination antiretroviral therapy (cART) enhances the hepatitis B surface antigen (HBsAg) clearance rate in Human Immunodeficiency Virus-1/Hepatitis B Virus (HIV/HBV) coinfected patients, yet the associated immunological characteristics remain unclear. METHODS: Global and specific immune phenotypic profiles were examined in 48 patients with HIV/HBV coinfection before cART and at 1-year, and 3-year after cART using flow cytometry. In addition, 61 patients with HBV monoinfection were included for comparison. RESULTS: HBsAg response (sAg-R) was defined as > 0.5 log decrease within six months of cART initiation, and 16 patients achieved it. Patients with sAg-R (the sAg-R group) exhibited distinct immune phenotypes compared to those of HBsAg-retained patients (the sAg-NR group). Notably, patients with sAg-R had lower CD4+ T cell counts and a higher number of HBcAg-specific T cells. Further, the sAg-R group exhibited upregulation of HLA-DR, Ki67, and PD-1 in CD4+ T cells and heightened HLA-DR and T-bet in CD8+ T cells. However, the sAg-R group had fewer TEMRA cells but more TEM and Th17 cells than those in the sAg-NR group. Expression of various markers, including HLA-DR+CD4+, Ki67+CD4+, PD-1+CD4+, CD38+CD8+, HLA-DR+CD8+, TIM-3+CD8+, HBV-specific CD4+ T cell secreting IFN-γ and IL-2, and specific CD8+ T cell secreting IFN-γ and IL-2, correlated with HBsAg decrease. CONCLUSION: The decline in HBsAg levels during cART in HIV/HBV coinfection involves significant alterations in CD4+ and CD8+ T cells phenotypes, offering a novel perspective on a functional HBV cure.


Assuntos
Coinfecção , Infecções por HIV , Antígenos de Superfície da Hepatite B , Hepatite B , Humanos , Infecções por HIV/imunologia , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Masculino , Coinfecção/virologia , Coinfecção/imunologia , Feminino , Adulto , Hepatite B/complicações , Hepatite B/imunologia , Hepatite B/virologia , Hepatite B/sangue , Pessoa de Meia-Idade , Linfócitos T/imunologia , Linfócitos T CD8-Positivos/imunologia , Vírus da Hepatite B/imunologia , Fenótipo
13.
Nat Mater ; 22(6): 710-716, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37081170

RESUMO

Hydrogen embrittlement jeopardizes the use of high-strength steels in critical load-bearing applications. However, uncertainty regarding how hydrogen affects dislocation motion, owing to the lack of quantitative experimental evidence, hinders our understanding of hydrogen embrittlement. Here, by studying the well-controlled, cyclic, bow-out motions of individual screw dislocations in α-iron, we find that the critical stress for initiating dislocation motion in a 2 Pa electron-beam-excited H2 atmosphere is 27-43% lower than that in a vacuum environment, proving that hydrogen enhances screw dislocation motion. Moreover, we find that aside from vacuum degassing, cyclic loading and unloading facilitates the de-trapping of hydrogen, allowing the dislocation to regain its hydrogen-free behaviour. These findings at the individual dislocation level can inform hydrogen embrittlement modelling and guide the design of hydrogen-resistant steels.

14.
PLoS Pathog ; 18(8): e1010765, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35921364

RESUMO

Streptococcus suis serotype 2 (SS2) is a major zoonotic pathogen resulting in manifestations as pneumonia and septic shock. The upper respiratory tract is typically thought to be the main colonization and entry site of SS2 in pigs, but the mechanism through which it penetrates the respiratory barrier is still unclear. In this study, a mutant with low invasive potential to swine tracheal epithelial cells (STECs) was screened from the TnYLB-1 transposon insertion mutant library of SS2, and the interrupted gene was identified as autolysin (atl). Compared to wild-type (WT) SS2, Δatl mutant exhibited lower ability to penetrate the tracheal epithelial barrier in a mouse model. Purified Atl also enhanced SS2 translocation across STEC monolayers in Transwell inserts. Furthermore, Atl redistributed the tight junctions (TJs) in STECs through myosin light chain kinase (MLCK) signaling, which led to increased barrier permeability. Using mass spectrometry, co-immunoprecipitation (co-IP), pull-down, bacterial two-hybrid and saturation binding experiments, we showed that Atl binds directly to vimentin. CRISPR/Cas9-targeted deletion of vimentin in STECs (VIM KO STECs) abrogated the capacity of SS2 to translocate across the monolayers, SS2-induced phosphorylation of myosin II regulatory light chain (MLC) and MLCK transcription, indicating that vimentin is indispensable for MLCK activation. Consistently, vimentin null mice were protected from SS2 infection and exhibited reduced tracheal and lung injury. Thus, MLCK-mediated epithelial barrier opening caused by the Atl-vimentin interaction is found to be likely the key mechanism by which SS2 penetrates the tracheal epithelium.


Assuntos
Infecções Estreptocócicas , Streptococcus suis , Animais , Epitélio , Camundongos , N-Acetil-Muramil-L-Alanina Amidase/metabolismo , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Suínos , Junções Íntimas/metabolismo , Vimentina/genética , Vimentina/metabolismo
15.
J Bioenerg Biomembr ; 56(2): 181-191, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38411863

RESUMO

Lung adenocarcinoma (LUAD) is one of the most lethal and common malignancies. The energy metabolism of LUAD is a critical factor affecting its malignant progression, and research on this topic can aid in the development of novel cancer treatment targets. Bioinformatics analysis of the expression of long non-coding RNA (lncRNA) LINC00665 in LUAD was performed. Downstream regulatory molecules of LINC00665 were predicted using the StarBase database. We used quantitative reverse transcription polymerase chain reaction and western blot to measure the expression at mRNA and protein levels, respectively. The effects of the LINC00665/let-7c-5p/HMMR axis on cell viability in vitro were tested by CCK-8 assay. The regulatory effects on glycolysis were analyzed by extracellular acidification rate, oxygen consumption rate, glucose uptake, adenosine triphosphate production, and lactate production. The predicted competitive endogenous RNA mechanism between LINC00665 and let-7c-5p/HMMR was verified by a dual-luciferase reporter gene assay. LINC00665 was upregulated in LUAD. Silencing LINC00665 inhibited tumor proliferation and reduced the glycolytic activity of tumor cells. Additionally, the expression of LINC00665 had a negative correlation with that of let-7c-5p, while the expression of HMMR was remarkably inhibited by let-7c-5p. HMMR could affect the development of LUAD by influencing glycolytic capacity. Mechanistically, LINC00665 acted as a molecular sponge to absorb let-7c-5p and targeted HMMR. Transfection of let-7c-5p inhibitor or overexpression of HMMR plasmid could reverse the inhibition in proliferation and glycolysis of LUAD cells induced by silencing of LINC00665. In summary, this study demonstrated that the LINC00665/let-7c-5p/HMMR regulatory axis promoted the tumorigenesis of LUAD by enhancing aerobic glycolysis, suggesting that this regulatory axis was an effective target for inhibiting LUAD progression and providing theoretical support for the development of new drugs for LUAD.


Assuntos
Adenocarcinoma , MicroRNAs , Humanos , Glicólise , Metabolismo Energético , Sobrevivência Celular , Pulmão , MicroRNAs/genética , Proliferação de Células , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica
16.
J Med Virol ; 96(5): e29673, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38767184

RESUMO

The SARS-CoV-2 virus is responsible for the human disease known as COVID-19. This virus is capable of generating a spectrum of infections ranging from moderate to severe. Serum apolipoprotein E (ApoE) inhibits inflammation by preserving immune regulatory function. Nonetheless, the relationship between serum ApoE and clinical prognosis in omicron remains elusive. A cohort of 231 patients was observed for 65 days, with death as the primary outcome. Based on their ApoE levels, the patients were categorized into patients with elevated ApoE levels and those with lower ApoE levels. To do statistical comparisons, the log-rank test was utilized, and the Kaplan-Meier method was utilized to estimate survival rates. Cox hazard models, both univariate and multivariate, were employed to examine the prognostic relevance. According to our research, omicron had significantly greater ApoE levels. In mild-to-moderate and severe cases, the study identified a statistically significant variation in ApoE levels. Additionally, there was a drop in overall survival that is statistically significant (OS, p < 0.0001) for patients with greater ApoE levels. Multiple Cox proportional hazards regression analysis indicates that an elevated ApoE level was determined to be an adverse and independent prognostic factor of OS in patients with omicron. Taken together, our study found that the level of serum ApoE at the time of initial diagnosis was substantially connected to the severity and prognosis of omicron. Consequently, we propose that ApoE might be a poor prognostic factor in individuals afflicted with the omicron variant.


Assuntos
Apolipoproteínas E , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/mortalidade , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/virologia , Feminino , Masculino , Prognóstico , Pessoa de Meia-Idade , Apolipoproteínas E/genética , Apolipoproteínas E/sangue , Idoso , Modelos de Riscos Proporcionais , Adulto , Estimativa de Kaplan-Meier , Índice de Gravidade de Doença
17.
Plant Cell Environ ; 2024 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-39462913

RESUMO

Nitrate (NO3 -) deficiency decreases root water uptake and root hydraulic conductance. This adaptive response is correlated with reduced abundance and activity of plasma membrane intrinsic protein (PIP) aquaporins. We therefore screened changes in the root architecture of a complete set of Arabidopsis pip loss-of-function mutants grown under NO3 - deficiency to systematically approach the impact of PIPs under these conditions. NO3 - deprivation led to attenuated responses of specific pip single mutants compared to the strongly altered LR parameters of wild-type plants. In particular, pip1;1 exhibited a lower relative reduction in LR length and LR density, revealing that PIP1;1 represses LR development when NO3 - is scarce. Indeed, PIP1;1 compromises root and shoot NO3 - accumulation during early developmental stages. A fluorescent VENUS-PIP1;1 fusion revealed that PIP1;1 is specifically repressed in the pericycle, endodermis and at the flanks of emerging LRs upon NO3 - deficiency. Thus, LR plasticity and NO3 - uptake are affected by an interactive mechanism involving aquaporins (PIP1;1) and nitrate accumulation during seedling development under NO3 --deficient conditions.

18.
Haematologica ; 109(2): 458-465, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37470145

RESUMO

Primary hemophagocytic lymphohistiocytosis (pHLH) is a rare immune disorder and hematopoietic stem cell transplan- tation (HSCT) is the only potentially curative treatment. Given the high pre-HSCT mortality of pHLH patients reported in the HLH-2004 study (17%), more regimens to effectively control the disease and form a bridge with HSCT are needed. We conducted a retrospective study of pHLH children treated by ruxolitinib (RUX)-based regimen. Generally, patients received RUX until HSCT or unacceptable toxic side-effect. Methylprednisolone and etoposide were added sequentially when the disease was suboptimally controlled. The primary end point was 1-year overall survival. Twenty-one pHLH patients (12 previously treated and 9 previously untreated) were included with a median follow-up of 1.4 years. At last follow-up, 17 (81.0%) patients were alive with a 1-year overall survival of 90.5% (95% confidence interval: 84.1-96.9). Within the first 8 weeks, all patients had an objective response, of which 19 (90.5%) achieved complete response (CR) and two (9.5%) achieved partial response (PR) as a best response. Seventeen (81.0%) patients received HSCT, of which 13 (76.5%) had CR, three (17.6%) had PR and one (5.9%) had disease reactivation at the time of HSCT. Fifteen (88.2) patients were alive post- HSCT. Notably, eight (38.1%) patients received zero doses of etoposide, suggesting the potential of RUX-based regimen to reduce chemotherapy intensity. Patients tolerated RUX-based regimen well and the most frequently observed adverse events were hematologic adverse events. Overall, RUX-based regimen was effective and safe and could be used as a bridge to HSCT for pHLH children.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfo-Histiocitose Hemofagocítica , Nitrilas , Pirazóis , Pirimidinas , Criança , Humanos , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Linfo-Histiocitose Hemofagocítica/etiologia , Resultado do Tratamento , Estudos Retrospectivos , Etoposídeo/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Resposta Patológica Completa
19.
Ann Hematol ; 103(5): 1765-1774, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38509388

RESUMO

Gaucher disease (GD) is an autosomal recessive ailment resulting from glucocerebrosidase deficiency caused by a mutation in the GBA1 gene, leading to multi-organ problems in the liver, spleen, and bone marrow. In China, GD is extremely uncommon and has a lower incidence rate than worldwide. In this study, we report the case of an adult male with an enlarged spleen for 13 years who presented with abdominal distension, severe loss of appetite and weight, reduction of the three-line due to hypersplenism, frequent nosebleeds, and bloody stools. Regrettably, the unexpected discovery of splenic pathology suggestive of splenic Gaucher disease was only made after a splenectomy due to a lack of knowledge about rare disorders. Our patient's delayed diagnosis may have been due to the department where he was originally treated, but it highlights the need for multidisciplinary consultation in splenomegaly of unknown etiology. We then investigated the patient's clinical phenotypes and gene mutation features using genetically phenotypical analysis. The analysis of the GBA1 gene sequence indicated that the patient carried a compound heterozygous mutation consisting of two potentially disease-causing mutations: c.907C > A (p. Leu303Ile) and c.1448 T > C (p. Leu483Pro). While previous research has linked the p. Leu483Pro mutation site to neurologic GD phenotypes (GD2 and GD3), the patients in this investigation were identified as having non-neuronopathic GD1. The other mutation, p. Leu303Ile, is a new GD-related mutation not indexed in PubMed that enriches the GBA1 gene mutation spectrum. Biosignature analysis has shown that both mutations alter the protein's three-dimensional structure, which may be a pathogenic mechanism for GD1 in this patient.


Assuntos
Doença de Gaucher , Esplenopatias , Adulto , Humanos , Masculino , Doença de Gaucher/complicações , Doença de Gaucher/genética , Doença de Gaucher/cirurgia , Esplenectomia , Medula Óssea , Fenótipo , Esplenomegalia/genética , Mutação , Glucosilceramidase/genética
20.
Pediatr Blood Cancer ; 71(6): e30970, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38556751

RESUMO

Langerhans cell histiocytosis (LCH) is a rare hematologic neoplasm characterized by the clonal proliferation of Langerhans-like cells. Colony-stimulating factor 1 receptor (CSF1R) is a membrane-bound receptor that is highly expressed in LCH cells and tumor-associated macrophages. In this study, a soluble form of CSF1R protein (sCSF1R) was identified by plasma proteome profiling, and its role in evaluating LCH prognosis was explored. We prospectively measured plasma sCSF1R levels in 104 LCH patients and 10 healthy children using ELISA. Plasma sCSF1R levels were greater in LCH patients than in healthy controls (p < .001) and significantly differed among the three disease extents, with the highest level in MS RO+ LCH patients (p < .001). Accordingly, immunofluorescence showed the highest level of membrane-bound CSF1R in MS RO+ patients. Furthermore, the plasma sCSF1R concentration at diagnosis could efficiently predict the prognosis of LCH patients treated with standard first-line treatment (AUC = 0.782, p < .001). Notably, dynamic monitoring of sCSF1R levels could predict relapse early in patients receiving BRAF inhibitor treatment. In vitro drug sensitivity data showed that sCSF1R increased resistance to Ara-C in THP-1 cells expressing ectopic BRAF-V600E. Overall, the plasma sCSF1R level at diagnosis and during follow-up is of great clinical importance in pediatric LCH patients.


Assuntos
Histiocitose de Células de Langerhans , Receptor de Fator Estimulador de Colônias de Macrófagos , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos , Humanos , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/patologia , Histiocitose de Células de Langerhans/sangue , Masculino , Feminino , Criança , Prognóstico , Pré-Escolar , Lactente , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/sangue , Adolescente , Estudos Prospectivos , Seguimentos
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