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1.
Proc Natl Acad Sci U S A ; 119(39): e2202563119, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36122234

RESUMO

Hundreds of members have been synthesized and versatile applications have been promised for endofullerenes (EFs) in the past 30 y. However, the formation mechanism of EFs is still a long-standing puzzle to chemists, especially the mechanism of embedding clusters into charged carbon cages. Here, based on synthesis and structures of two representative vanadium-scandium-carbido/carbide EFs, VSc2C@Ih (7)-C80 and VSc2C2@Ih (7)-C80, a reasonable mechanism-C1 implantation (a carbon atom is implanted into carbon cage)-is proposed to interpret the evolution from VSc2C carbido to VSc2C2 carbide cluster. Supported by theoretical calculations together with crystallographic characterization, the single electron on vanadium (V) in VSc2C@Ih (7)-C80 is proved to facilitate the C1 implantation. While the V=C double bond is identified for VSc2C@Ih (7)-C80, after C1 implantation the distance between V and C atoms in VSc2C2@Ih (7)-C80 falls into the range of single bond lengths as previously shown in typical V-based organometallic complexes. This work exemplifies in situ self-driven implantation of an outer carbon atom into a charged carbon cage, which is different from previous heterogeneous implantation of nonmetal atoms (Group-V or -VIII atoms) driven by high-energy ion bombardment or high-pressure offline, and the proposed C1 implantation mechanism represents a heretofore unknown metal-carbon cluster encapsulation mechanism and can be the fundamental basis for EF family genesis.

2.
Kidney Int ; 105(5): 1020-1034, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38387504

RESUMO

The circadian clock influences a wide range of biological process and controls numerous aspects of physiology to adapt to the daily environmental changes caused by Earth's rotation. The kidney clock plays an important role in maintaining tubular function, but its effect on podocytes remains unclear. Here, we found that podocytes expressed CLOCK proteins, and that 2666 glomerular gene transcripts (13.4%), including autophagy related genes, had 24-hour circadian rhythms. Deletion of Clock in podocytes resulted in 1666 gene transcripts with the loss of circadian rhythm including autophagy genes. Podocyte-specific Clock knockout mice at age three and eight months showed deficient autophagy, loss of podocytes and increased albuminuria. Chromatin immunoprecipitation (ChIP) sequence analysis indicated autophagy related genes were targets of CLOCK in podocytes. ChIP-PCR further confirmed Clock binding to the promoter regions of Becn1 and Atg12, two autophagy related genes. Furthermore, the association of CLOCK regulated autophagy with chronic sleep fragmentation and diabetic kidney disease was analyzed. Chronic sleep fragmentation resulted in the loss of glomerular Clock rhythm, inhibition of podocyte autophagy, and proteinuria. Rhythmic oscillations of Clock also disappeared in high glucose treated podocytes and in glomeruli from diabetic mice. Finally, circadian differences in podocyte autophagy were also abolished in diabetic mice. Deletion Clock in podocytes aggravated podocyte injury and proteinuria in diabetic mice. Thus, our findings demonstrate that clock-dependent regulation of autophagy may be essential for podocyte survival. Hence. loss of circadian controlled autophagy may play an important role in podocyte injury and proteinuria.


Assuntos
Diabetes Mellitus Experimental , Nefropatias Diabéticas , Podócitos , Camundongos , Animais , Podócitos/metabolismo , Diabetes Mellitus Experimental/complicações , Privação do Sono/complicações , Privação do Sono/metabolismo , Proteinúria/genética , Proteinúria/metabolismo , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/complicações , Camundongos Knockout , Autofagia
3.
Sensors (Basel) ; 24(12)2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38931527

RESUMO

The identification and detection of pesticides is crucial to protecting both the environment and human health. However, it can be challenging to conveniently and rapidly differentiate between different types of pesticides. We developed a supramolecular fluorescent sensor array, in which calixarenes with broad-spectrum encapsulation capacity served as recognition receptors. The sensor array exhibits distinct fluorescence change patterns for seven tested pesticides, encompassing herbicides, insecticides, and fungicides. With a reaction time of just three minutes, the sensor array proves to be a rapid and efficient tool for the discrimination of pesticides. Furthermore, this supramolecular sensing approach can be easily extended to enable real-time and on-site visual detection of varying concentrations of imazalil using a smartphone with a color scanning application. This work not only provides a simple and effective method for pesticide identification and quantification, but also offers a versatile and advantageous platform for the recognition of other analytes in relevant fields.


Assuntos
Calixarenos , Praguicidas , Calixarenos/química , Praguicidas/análise , Técnicas Biossensoriais/métodos , Smartphone , Espectrometria de Fluorescência/métodos
4.
J Fish Biol ; 104(5): 1308-1325, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38310927

RESUMO

We report on the feeding ecology of two species, the short-headed lanternfish Diaphus brachycephalus and Warming's lanternfish Ceratoscopelus warmingii, using data collected over five surveys from 2015 to 2017 in the open South China Sea. D. brachycephalus feed mainly on copepods, with few differences in food composition between different-sized individuals; the diet of C. warmingii is more diverse, including crustacean zooplankton, gelatinous animals, and Mollusca, and differs significantly between fishes >55 mm in body length and smaller fishes. Interspecific competition for food between these two species is not strong, while intraspecific competition may be more intense in D. brachycephalus than in C. warmingii. Trophic levels of D. brachycephalus (3.46) and C. warmingii (3.38) identify both species as third-trophic-level lower carnivores. The diel feeding patterns of D. brachycephalus and C. warmingii differ: the former feeds actively both day and night when food is plentiful, and feeds primarily in the upper layer at night and in the mesopelagic layer during the daytime, and the latter ascends into the upper 100 m at night to feed, but stomach fullness is lower than D. brachycephalus. Dry-body-weight daily ration estimates for D. brachycephalus range from 5.19% to 16.46%, and those for C. warmingii range from 1.38% to 4.39%.


Assuntos
Dieta , Comportamento Alimentar , Peixes , Animais , Peixes/fisiologia , Dieta/veterinária , China , Cadeia Alimentar , Tamanho Corporal
5.
Compr Rev Food Sci Food Saf ; 23(3): e13349, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38638060

RESUMO

3D printing is an additive manufacturing technology that locates constructed models with computer-controlled printing equipment. To achieve high-quality printing, the requirements on rheological properties of raw materials are extremely restrictive. Given the special structure and high modifiability under external physicochemical factors, the rheological properties of proteins can be easily adjusted to suitable properties for 3D printing. Although protein has great potential as a printing material, there are many challenges in the actual printing process. This review summarizes the technical considerations for protein-based ink 3D printing. The physicochemical factors used to enhance the printing adaptability of protein inks are discussed. The post-processing methods for improving the quality of 3D structures are described, and the application and problems of fourth dimension (4D) printing are illustrated. The prospects of 3D printing in protein manufacturing are presented to support its application in food and cultured meat. The native structure and physicochemical factors of proteins are closely related to their rheological properties, which directly link with their adaptability for 3D printing. Printing parameters include extrusion pressure, printing speed, printing temperature, nozzle diameter, filling mode, and density, which significantly affect the precision and stability of the 3D structure. Post-processing can improve the stability and quality of 3D structures. 4D design can enrich the sensory quality of the structure. 3D-printed protein products can meet consumer needs for nutritional or cultured meat alternatives.


Assuntos
Tinta , Impressão Tridimensional , Alimentos , Carne in vitro , Substitutos da Carne
6.
Small ; 19(42): e2303061, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37340882

RESUMO

Developing anode catalysts with substantially enhanced activity for hydrogen oxidation reaction (HOR) and CO tolerance performance is of great importance for the commercial applications of proton exchange membrane fuel cells (PEMFCs). Herein, an excellent CO-tolerant catalyst (Pd-WO3 /C) has been fabricated by loading Pd nanoparticles on WO3 via an immersion-reduction route. A remarkably high power density of 1.33 W cm-2 at 80 °C is obtained by using the optimized 3Pd-WO3 /C as the anode catalyst of PEMFCs, and the moderately reduced power density (73% remained) in CO/H2 mixed gas can quickly recover after removal of CO-contamination from hydrogen fuel, which is not possible by using Pt/C or Pd/C as anode catalyst. The prominent HOR activity of 3Pd-WO3 /C is attributed to the optimized interfacial electron interaction, in which the activated H* adsorbed on Pd species can be effectively transferred to WO3 species through hydrogen spillover effect and then oxidized through the H species insert/output effect during the formation of Hx WO3 in acid electrolyte. More importantly, a novel synergetic catalytic mechanism about excellent CO tolerance is proposed, in which Pd and WO3 respectively absorbs/activates CO and H2 O, thus achieving the CO electrooxidation and re-exposure of Pd active sites for CO-tolerant HOR.

7.
Hepatology ; 75(2): 403-418, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34435375

RESUMO

BACKGROUND AND AIMS: Although the prevalence of NAFLD has risen dramatically to 25% of the adult population worldwide, there are as yet no approved pharmacological interventions for the disease because of uncertainty about the underlying molecular mechanisms. It is known that mitochondrial dysfunction is an important factor in the development of NAFLD. Mitochondrial antiviral signaling protein (MAVS) is a critical signaling adaptor for host defenses against viral infection. However, the role of MAVS in mitochondrial metabolism during NAFLD progression remains largely unknown. APPROACH AND RESULTS: Based on expression analysis, we identified a marked down-regulation of MAVS in hepatocytes during NAFLD progression. By using MAVS global knockout and hepatocyte-specific MAVS knockout mice, we found that MAVS is protective against diet-induced NAFLD. MAVS deficiency induces extensive mitochondrial dysfunction during NAFLD pathogenesis, which was confirmed as impaired mitochondrial respiratory capacity and membrane potential. Metabolomics data also showed the extensive metabolic disorders after MAVS deletion. Mechanistically, MAVS interacts with the N-terminal stretch of voltage-dependent anion channel 2 (VDAC2), which is required for the ability of MAVS to influence mitochondrial function and hepatic steatosis. CONCLUSIONS: In hepatocytes, MAVS plays an important role in protecting against NAFLD by helping to regulate healthy mitochondrial function. These findings provide insights regarding the metabolic importance of conventional immune regulators and support the possibility that targeting MAVS may represent an avenue for treating NAFLD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Animais , Células Cultivadas , Progressão da Doença , Regulação para Baixo , Técnicas de Silenciamento de Genes , Células Estreladas do Fígado , Hepatócitos , Homeostase , Humanos , Lipogênese/genética , Masculino , Metabolômica , Camundongos , Camundongos Knockout , Mitocôndrias/fisiologia , Hepatopatia Gordurosa não Alcoólica/genética , Cultura Primária de Células , Canal de Ânion 2 Dependente de Voltagem/genética , Canal de Ânion 2 Dependente de Voltagem/metabolismo
8.
Ren Fail ; 45(2): 2278310, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37936488

RESUMO

OBJECTIVE: This study aimed to analyze the association between sleep quality and cardiovascular disease in patients on maintenance hemodialysis (MHD). METHODS: A total of 601 patients with MHD in the second affiliated hospital of Nanjing Medical University, were prospectively enrolled in this cohort study from January 2019 to December2019. The global Pittsburgh sleep quality index (PSQI) score > 7 indicates that a person with poor sleep quality. Patients were divided into two groups according to the PSQI score. Follow-up was conducted about 3 years with all-cause death and major adverse cardiovascular events (MACEs) as the endpoint events. RESULTS: Of the 601 patients, 595 patients completed the PSQI assessment, with 278 patients having poor sleep quality. Patients in the PSQI > 7 group were older and had a higher proportion of cardiovascular disease or diabetes. Years of education, diastolic blood pressure, and heart rate were lower in the PSQI > 7 group. At a mean follow-up period of 3 years, 116 patients died, 64 patients were lost to follow-up, and 115 patients experienced MACEs. After adjusting for confounding factors such as age, gender, dialysis age, and previous cardiovascular disease, the risk of MACE in patients with poor sleep quality was twice that of patients with good sleep quality (HR = 2.037 (1.339, 3.097), p = 0.001). There was no significant difference in the risk of all-cause death between the two groups. CONCLUSION: The prevalence of poor sleep quality was 46.7% in patients with MHD. Poor sleep quality was an independent risk factor for MACEs in patients with MHD.


Assuntos
Doenças Cardiovasculares , Distúrbios do Início e da Manutenção do Sono , Transtornos do Sono-Vigília , Humanos , Qualidade do Sono , Estudos de Coortes , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Estudos Prospectivos , Diálise Renal/efeitos adversos , Transtornos do Sono-Vigília/epidemiologia , Transtornos do Sono-Vigília/etiologia , Sono/fisiologia
9.
J Am Chem Soc ; 144(22): 10080-10090, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35639413

RESUMO

There is a growing interest in constructing multicyclic peptide structures to expand the chemical space of peptides. Conventional strategies for constructing large peptide structures are limited by the typical reliance on the inflexible coupling between premade templates equipped with fixed reactive handles and peptide substrates via cysteine anchors. Herein, we report the development of a facile three-component condensation reaction of primary alkyl amine, formaldehyde, and guanidine for construction of complex macromulticyclic peptides with novel topologies via lysine anchors. Moreover, the reaction sequences can be orchestrated in different anchor combinations and spatial arrangements to generate various macrocyclic structures crosslinked by distinct fused tetrahydrotriazine linkages. The macrocyclization reactions are selective, efficient, versatile, and workable in both organic and aqueous media. Thus, the condensation reaction provides a smart tool for stitching native peptides in situ using simple methylene threads and guanidine joints in a flexible and programmable manner.


Assuntos
Lisina , Peptídeos , Cisteína/química , Formaldeído/química , Guanidina , Lisina/química , Peptídeos/química
10.
J Am Chem Soc ; 144(24): 10736-10742, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35671378

RESUMO

Herein, a nitrogen-embedded quintuple [7]helicene (N-Q7H) with an azapentabenzocorannulene core, which can be considered to be a helicene/azacorannulene hybrid π-system, was synthesized from azapentabenzocorannulene in a three-step process. N-Q7H is the first example of a multiple helicene with an azabuckybowl core. Single-crystal X-ray diffractometry unambiguously confirmed the structure of the propeller-shaped hybrid π-system. Owing to nitrogen-atom doping in the multiple helicenes and effective hybridization between the helicene and azacorannulene, N-Q7H exhibits considerably redshifted absorption and emission (yellow-to-green color change and green-to-near-infrared fluorescence change) relative to the azapentabenzocorannulene core. The broad absorption from the ultraviolet-visible to the NIR region is ascribable to the allowed transition between the highest occupied molecular orbital and the lowest unoccupied molecular orbital after symmetry breaking, as revealed by density functional theory calculations. Compared to previous propeller-shaped multiple helicenes with corannulene or hexabenzocoronene (etc.) as cores, N-Q7H demonstrates a significantly higher NIR fluorescence quantum efficiency of 28%. Additionally, the chiral-resolution and redox properties of N-Q7H were investigated. The excellent photophysical and inherent chiral properties of N-Q7H suggest that azapentabenzocorannulene can be used as an outstanding nitrogen-embedded core to construct novel multiple helicenes with wide application potential, including as NIR fluorescent bio-probes.

11.
Br J Cancer ; 126(12): 1684-1694, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35194191

RESUMO

BACKGROUND: Lymph node (LN) metastasis confers gastric cancer (GC) progression, poor survival and cancer-related death. Aberrant activation of Wnt/ß-catenin promotes epithelial-mesenchymal transition (EMT) and LN metastasis, whereas the constitutive activation mutation of Wnt/ß-catenin is rare in GC, suggesting that the underlying mechanisms enhancing Wnt/ß-catenin activation need to be further investigated and understood. METHODS: Bioinformatics analyses and immunohistochemistry (IHC) were used to identify and detect LN metastasis-related genes in GC. Cellular functional assays and footpad inoculation mouse model illustrate the biological function of CCT5. Co-immunoprecipitation assays, western blot and qPCR elucidate the interaction between CCT5 and E-cadherin, and the regulation on ß-catenin activity. RESULTS: CCT5 is upregulated in LN metastatic GCs and correlates with poor prognosis. In vitro assays prove that CCT5 markedly promotes GC cell proliferation, anti-anoikis, invasion and lymphatic tube formation. Moreover, CCT5 enhances xenograft GC growth and popliteal lymph node metastasis in vivo. Furthermore, CCT5 binds the cytoplasmic domain of E-cadherin and abrogates the interaction between E-cadherin and ß-catenin, thereby releasing ß-catenin to the nucleus and enhancing Wnt/ß-catenin signalling activity and EMT. CONCLUSION: CCT5 promotes GC progression and LN metastasis by enhancing wnt/ß-catenin activation, suggesting a great potential of CCT5 as a biomarker for GC diagnosis and therapy.


Assuntos
Chaperonina com TCP-1 , Neoplasias Gástricas , Via de Sinalização Wnt , Animais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Chaperonina com TCP-1/genética , Chaperonina com TCP-1/metabolismo , Transição Epitelial-Mesenquimal/genética , Xenoenxertos , Humanos , Metástase Linfática , Camundongos , Metástase Neoplásica , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , beta Catenina/genética , beta Catenina/metabolismo
12.
Small ; 18(48): e2204443, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36257819

RESUMO

Earth-abundant tungsten carbide exhibits potential hydrogen evolution reaction (HER) catalytic activity owing to its Pt-like d-band electronic structure, which, unfortunately, suffers from the relatively strong tungsten-hydrogen binding, deteriorating its HER performance. Herein, a catalyst design concept of incorporating late transition metal into early transition metal carbide is proposed for regulating the metal-H bonding strength and largely enhancing the HER performance, which is employed to synthesize CoW bi-metallic carbide Co6 W6 C by a "disassembly-assembly" approach in a confined environment. Such synthesized Co6 W6 C nanocatalyst features the optimal Gibbs free energy of *H intermediate and dissociation barrier energy of H2 O molecules as well by taking advantage of the electron complementary effect between Co and W species, which endows the electrocatalyst with excellent HER performance in both alkaline and seawater/alkaline electrolytes featuring especially low overpotentials, elevated current densities, and much-enhanced operation durability in comparison to commercial Pt/C catalyst. Moreover, a proof-of-concept Mg/seawater battery equipped with Co6 W6 C-2-600 as cathode offers a peak power density of 9.1 mW cm-2 and an open-circuit voltage of ≈1.71 V, concurrently realizing hydrogen production and electricity output.

13.
Hepatology ; 74(5): 2508-2525, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34231239

RESUMO

BACKGROUND AND AIMS: NAFLD is the most prevalent chronic liver disease without any Food and Drug Administration-approved pharmacological intervention in clinic. Fatty acid synthase (FASN) is one of the most attractive targets for NAFLD treatment because of its robust rate-limiting capacity to control hepatic de novo lipogenesis. However, the regulatory mechanisms of FASN in NAFLD and potential therapeutic strategies targeting FASN remain largely unknown. METHODS AND RESULTS: Through a systematic interactomics analysis of FASN-complex proteins, we screened and identified sorting nexin 8 (SNX8) as a binding partner of FASN. SNX8 directly bound to FASN and promoted FASN ubiquitination and subsequent proteasomal degradation. We further demonstrated that SNX8 mediated FASN protein degradation by recruiting the E3 ligase tripartite motif containing 28 (TRIM28) and enhancing the TRIM28-FASN interaction. Notably, Snx8 interference in hepatocytes significantly deteriorated lipid accumulation in vitro, whereas SNX8 overexpression markedly blocked hepatocyte lipid deposition. Furthermore, the aggravating effect of Snx8 deletion on NAFLD was validated in vivo as hepatic steatosis and lipogenic pathways in the liver were significantly exacerbated in Snx8-knockout mice compared to wild-type controls. Consistently, hepatocyte-specific overexpression of Snx8 in vivo markedly suppressed high-fat, high-cholesterol diet (HFHC)-induced hepatic steatosis. Notably, the protective effect of SNX8 against NAFLD was largely dependent on FASN suppression. CONCLUSIONS: These data indicate that SNX8 is a key suppressor of NAFLD that promotes FASN proteasomal degradation. Targeting the SNX8-FASN axis is a promising strategy for NAFLD prevention and treatment.


Assuntos
Ácido Graxo Sintase Tipo I/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Transdução de Sinais/genética , Nexinas de Classificação/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Ácido Graxo Sintase Tipo I/antagonistas & inibidores , Ácido Graxo Sintase Tipo I/genética , Técnicas de Inativação de Genes , Células HEK293 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Lipogênese/efeitos dos fármacos , Lipogênese/genética , Masculino , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Nexinas de Classificação/genética , Transfecção , Ubiquitinação/genética , Ubiquitinas/metabolismo
14.
Hepatology ; 74(6): 3018-3036, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34272738

RESUMO

BACKGROUND AND AIMS: NAFLD is the most prevalent chronic liver disease worldwide, but no effective pharmacological therapeutics are available for clinical use. NASH is the more severe stage of NAFLD. During this progress, dysregulation of endoplasmic reticulum (ER)-related pathways and proteins is one of the predominant hallmarks. We aimed to reveal the role of ring finger protein 5 (RNF5), an ER-localized E3 ubiquitin-protein ligase, in NASH and to explore its underlying mechanism. APPROACH AND RESULTS: We first inspected the expression level of RNF5 and found that it was markedly decreased in livers with NASH in multiple species including humans. We then introduced adenoviruses for Rnf5 overexpression or knockdown into primary mouse hepatocytes and found that palmitic acid/oleic acid (PAOA)-induced lipid accumulation and inflammation in hepatocytes were markedly attenuated by Rnf5 overexpression but exacerbated by Rnf5 gene silencing. Hepatocyte-specific Rnf5 knockout significantly exacerbated hepatic steatosis, inflammatory response, and fibrosis in mice challenged with diet-induced NASH. Mechanistically, we identified 3-hydroxy-3-methylglutaryl CoA reductase degradation protein 1 (HRD1) as a binding partner of RNF5 by systematic interactomics analysis. RNF5 directly bound to HRD1 and promoted its lysine 48 (K48)-linked and K33-linked ubiquitination and subsequent proteasomal degradation. Furthermore, Hrd1 overexpression significantly exacerbated PAOA-induced lipid accumulation and inflammation, and short hairpin RNA-mediated Hrd1 knockdown exerted the opposite effects. Notably, Hrd1 knockdown significantly diminished PAOA-induced lipid deposition, and up-regulation of related genes resulted from Rnf5 ablation in hepatocytes. CONCLUSIONS: These data indicate that RNF5 inhibits NASH progression by targeting HRD1 in the ubiquitin-mediated proteasomal pathway. Targeting the RNF5-HRD1 axis may provide insights into the pathogenesis of NASH and pave the way for developing strategies for NASH prevention and treatment.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Membrana/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Biópsia , Proteínas de Ligação a DNA/análise , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Hepatócitos , Humanos , Fígado/patologia , Masculino , Proteínas de Membrana/análise , Camundongos , Cultura Primária de Células , Mapeamento de Interação de Proteínas , Proteólise , RNA-Seq , Ubiquitina-Proteína Ligases/análise , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
15.
Hepatology ; 74(3): 1319-1338, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33894019

RESUMO

BACKGROUND AND AIMS: NAFLD has become the most common liver disease worldwide but lacks a well-established pharmacological therapy. Here, we aimed to investigate the role of an E3 ligase SH3 domain-containing ring finger 2 (SH3RF2) in NAFLD and to further explore the underlying mechanisms. METHODS AND RESULTS: In this study, we found that SH3RF2 was suppressed in the setting of NAFLD across mice, monkeys, and clinical individuals. Based on a genetic interruption model, we further demonstrated that hepatocyte SH3RF2 deficiency markedly deteriorates lipid accumulation in cultured hepatocytes and diet-induced NAFLD mice. Mechanistically, SH3RF2 directly binds to ATP citrate lyase, the primary enzyme promoting cytosolic acetyl-coenzyme A production, and promotes its K48-linked ubiquitination-dependent degradation. Consistently, acetyl-coenzyme A was significantly accumulated in Sh3rf2-knockout hepatocytes and livers compared with wild-type controls, leading to enhanced de novo lipogenesis, cholesterol production, and resultant lipid deposition. CONCLUSION: SH3RF2 depletion in hepatocytes is a critical aggravator for NAFLD progression and therefore represents a promising therapeutic target for related liver diseases.


Assuntos
Proteínas de Transporte/genética , Hepatócitos/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Proteínas Oncogênicas/genética , Ubiquitina-Proteína Ligases/genética , Animais , Colesterol/metabolismo , Hepatócitos/patologia , Humanos , Lipogênese/genética , Fígado/patologia , Macaca fascicularis , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/metabolismo
16.
Lett Appl Microbiol ; 74(6): 901-908, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35218013

RESUMO

In the microbiome, probiotics modulate oral diseases. In this study, Streptococcus strain C17T was isolated from the oropharynx of a 5-year-old healthy child, and its potential probiotic properties were analysed using human bronchial epithelial cells (16-HBE) used as an in vitro oropharyngeal mucosal model. The results demonstrated that the C17T strain showed tolerance to moderate pH ranges of 4-5 and 0·5-1% bile. However, it was more tolerant to 0·5% bile than 1% bile. It also demonstrated an ability to accommodate maladaptive oropharyngeal conditions (i.e. tolerating lysozyme at 200 µg ml-1 ). It was also resistant to hydrogen peroxide at 0·8 mM. In addition, we found out that the strain possesses inhibitory activities against various common pathogenic bacteria. Furthermore, C17T was not cytotoxic to 16-HBE cells at different multiplicities of infection. Scanning electron microscopy disclosed that C17T adhesion to 16-HBE cells. Competition, exclusion and displacement assays showed that it had good anti-adhesive effect against S. aureus. The present study revealed that Streptococcus strain C17T is a potentially efficacious oropharyngeal probiotic.


Assuntos
Saúde Bucal , Probióticos , Streptococcus , Aderência Bacteriana , Pré-Escolar , Humanos , Probióticos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Streptococcus/genética
17.
Angew Chem Int Ed Engl ; 61(15): e202116290, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35075773

RESUMO

Fe-N-C electrocatalysts have been demonstrated to be the most promising substitutes for benchmark Pt/C catalysts for the oxygen reduction reaction (ORR). Herein, we report that N-doped carbon materials with trace amounts of iron (0-0.08 wt. %) show excellent ORR activity and durability comparable and even superior to those of Pt/C in both alkaline and acidic media without significant contribution by the metal sites. Such an N-doped carbon (denoted as N-HPCs) features a hollow and hierarchically porous architecture, and more importantly, a noncovalently bonded N-deficient/N-rich heterostructure providing the active sites for oxygen adsorption and activation owing to the efficient electron transfer between the layers. The primary Zn-air battery using N-HPCs as the cathode delivers a much higher power density of 158 mW cm-2 , and the maximum power density in the H2 -O2 fuel cell reaches 486 mW cm-2 , which is comparable to and even better than those using conventional Fe-N-C catalysts at cathodes.

18.
Angew Chem Int Ed Engl ; 61(32): e202207226, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35638129

RESUMO

A novel Zn-Fe flow battery featuring an Fe3+ reduction reaction (Fe3+ RR)-coupled zinc oxidation, and an Fe2+ oxidation reaction (Fe2+ OR)-coupled hydrogen evolution reaction (HER) system as well, was established. This battery is capable of driving two Fe2+ OR-coupled HER systems in series based on the above Fe2+ /Fe3+ cycling, for efficient self-powered hydrogen evolution. Meanwhile, this Fe2+ /Fe3+ cycling enables the preparation of a multifunctional catalyst, Pt-3@SXNS (siloxene nanosheet), by the Fe2+ OR-promoted dispersion of Pt nanoparticles on SXNS; alternatively, this support could be obtained by Fe3+ RR-assisted exfoliation using Fe3+ from the anolyte of Fe2+ OR-coupled HER. The Pt-3@SXNS catalyst exhibits excellent catalytic activities toward Fe3+ RR in the Zn-Fe flow battery, HER, and Fe2+ OR in the electrolyzer, which is attributed to the strong electronic interaction between Pt and Si. This work offers a new strategy for energy storage and low-cost hydrogen production from acidic wastewater.

19.
Angew Chem Int Ed Engl ; 61(33): e202204334, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35698274

RESUMO

Herein, a hetero(S,N)-quintuple [9]helicene (SNQ9H) molecule with an azacorannulene core was synthesized, currently representing the highest hetero-helicene reported in the field of multiple [n]helicenes. X-ray crystallography indicated that SNQ9H includes not only a propeller-shaped conformer SNQ9H-1, but also an unforeseen quasi-propeller-shaped conformer SNQ9H-2. Different conformers were observed for the first time in multiple [n≥9]helicenes, likely owing to the doping of heteroatomic sulfurs in the helical skeletons. Remarkably, the ratio of SNQ9H-1 to SNQ9H-2 can be regulated in situ by the reaction temperature. Experimental studies on the photophysical and redox properties of SNQ9H and theoretical calculations clearly demonstrated that the electronic structures of SNQ9H depend on their molecular conformations. The strategy of introducing heteroatomic sulfurs into the helical skeleton may be useful in constructing various conformers of higher multiple [n]helicenes in the future.

20.
Hepatology ; 71(1): 93-111, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31222801

RESUMO

Activation of apoptosis signal-regulating kinase 1 (ASK1) is a key driving force of the progression of nonalcoholic steatohepatitis (NASH) and represents an attractive therapeutic target for NASH treatment. However, the molecular and cellular mechanisms underlying ASK1 activation in the pathogenesis of NASH remain incompletely understood. In this study, our data unequivocally indicated that hyperactivated ASK1 in hepatocytes is a potent inducer of hepatic stellate cell (HSC) activation by promoting the production of hepatocyte-derived factors. Our previous serial studies have shown that the ubiquitination system plays a key role in regulating ASK1 activity during NASH progression. Here, we further demonstrated that tumor necrosis factor receptor-associated factor 6 (TRAF6) promotes lysine 6 (Lys6)-linked polyubiquitination and subsequent activation of ASK1 to trigger the release of robust proinflammatory and profibrotic factors in hepatocytes, which, in turn, drive HSC activation and hepatic fibrosis. Consistent with the in vitro findings, diet-induced liver inflammation and fibrosis were substantially attenuated in Traf6+/- mice, whereas hepatic TRAF6 overexpression exacerbated these abnormalities. Mechanistically, Lys6-linked ubiquitination of ASK1 by TRAF6 facilitates the dissociation of thioredoxin from ASK1 and N-terminal dimerization of ASK1, resulting in the boosted activation of ASK1-c-Jun N-terminal kinase 1/2 (JNK1/2)-mitogen-activated protein kinase 14(p38) signaling cascade in hepatocytes. Conclusion: These results suggest that Lys6-linked polyubiquitination of ASK1 by TRAF6 represents a mechanism underlying ASK1 activation in hepatocytes and a key driving force of proinflammatory and profibrogenic responses in NASH. Thus, inhibiting Lys6-linked polyubiquitination of ASK1 may serve as a potential therapeutic target for NASH treatment.


Assuntos
Apoptose , Hepatite/etiologia , Hepatócitos , Cirrose Hepática/etiologia , MAP Quinase Quinase Quinase 5/metabolismo , Fator 6 Associado a Receptor de TNF/fisiologia , Ubiquitinação , Animais , Lisina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Índice de Gravidade de Doença
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