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1.
Eur Heart J ; 43(43): 4579-4595, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-35929617

RESUMO

AIMS: Exercise confers protection against cardiovascular ageing, but the mechanisms remain largely unknown. This study sought to investigate the role of fibronectin type-III domain-containing protein 5 (FNDC5)/irisin, an exercise-associated hormone, in vascular ageing. Moreover, the existence of FNDC5/irisin in circulating extracellular vesicles (EVs) and their biological functions was explored. METHODS AND RESULTS: FNDC5/irisin was reduced in natural ageing, senescence, and angiotensin II (Ang II)-treated conditions. The deletion of FNDC5 shortened lifespan in mice. Additionally, FNDC5 deficiency aggravated vascular stiffness, senescence, oxidative stress, inflammation, and endothelial dysfunction in 24-month-old naturally aged and Ang II-treated mice. Conversely, treatment of recombinant irisin alleviated Ang II-induced vascular stiffness and senescence in mice and vascular smooth muscle cells. FNDC5 was triggered by exercise, while FNDC5 knockout abrogated exercise-induced protection against Ang II-induced vascular stiffness and senescence. Intriguingly, FNDC5 was detected in human and mouse blood-derived EVs, and exercise-induced FNDC5/irisin-enriched EVs showed potent anti-stiffness and anti-senescence effects in vivo and in vitro. Adeno-associated virus-mediated rescue of FNDC5 specifically in muscle but not liver in FNDC5 knockout mice, promoted the release of FNDC5/irisin-enriched EVs into circulation in response to exercise, which ameliorated vascular stiffness, senescence, and inflammation. Mechanistically, irisin activated DnaJb3/Hsp40 chaperone system to stabilize SIRT6 protein in an Hsp70-dependent manner. Finally, plasma irisin concentrations were positively associated with exercise time but negatively associated with arterial stiffness in a proof-of-concept human study. CONCLUSION: FNDC5/irisin-enriched EVs contribute to exercise-induced protection against vascular ageing. These findings indicate that the exerkine FNDC5/irisin may be a potential target for ageing-related vascular comorbidities.


Assuntos
Vesículas Extracelulares , Sirtuínas , Humanos , Camundongos , Animais , Idoso , Pré-Escolar , Fibronectinas/metabolismo , Fatores de Transcrição/metabolismo , Camundongos Knockout , Envelhecimento , Angiotensina II/farmacologia , Inflamação/metabolismo , Músculo Esquelético/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo
2.
Ecotoxicol Environ Saf ; 208: 111642, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396162

RESUMO

OBJECTIVES: Mercury (Hg), a ubiquitous heavy metal, could affect the neurodevelopment of the children, however, these associations are still equivocal. Brain derived neurotrophic factor (BDNF) plays an essential role in the central nervous system development in children. This study aimed to investigate the effects of low-level mercury exposure on serum BDNF levels and the influence of sex and dietary intake on these relationships in children. METHODS: In this cross-sectional study, a total of 541 pre-school children were recruited, the blood mercury concentrations and serum BDNF levels were measured. The background information on demographic characteristics and dietary habits of the children was collected through questionnaires. Multivariable linear models after adjustment for potential confounders were used to evaluate the associations between mercury exposure and levels of BDNF in children. RESULTS: The GMs of blood mercury concentrations and serum BDNF levels were 1.06 µg/L, 20.4 ng/mL, respectively. A significant positive association between blood mercury concentrations and serum BDNF levels was found. After stratification by sex, the blood mercury concentrations in children were positive associated with serum BDNF levels in girls but not in boys. However, these associations were attenuated when we further adjusted the children's dietary intake variables. CONCLUSIONS: Our findings suggest that low-levels of mercury exposure may have sex-specific effects on BDNF levels in young children and that dietary intake may be potential confounders in these relationships. However, further studies are warranted to investigate the role of BDNF in the effects of mercury on neurodevelopment.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Exposição Dietética/análise , Mercúrio/sangue , Criança , Pré-Escolar , Estudos Transversais , Exposição Dietética/estatística & dados numéricos , Feminino , Humanos , Masculino , Fatores Sexuais
3.
Physiol Plant ; 168(1): 98-117, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31017672

RESUMO

WRKY transcription factors play a key role in the tolerance of biotic and abiotic stresses across various crop species, but the function of some WRKY genes, particularly in tomato, remains unexplored. Here, we characterize the roles of a previously unstudied WRKY gene, SlWRKY8, in the resistance to pathogen infection and the tolerance to drought and salt stresses. Expression of SlWRKY8 was up-regulated upon Pseudomonas syringae pv. tomato DC3000 (Pst. DC3000), abiotic stresses such as drought, salt and cold, as well as ABA and SA treatments. The SlWRKY8 protein was localized to the nucleus with no transcription activation in yeast, but it could activate W-box-dependent transcription in plants. The overexpression of SlWRKY8 in tomato conferred a greater resistance to the pathogen Pst. DC3000 and resulted in the increased transcription levels of two pathogen-related genes SlPR1a1 and SlPR7. Moreover, transgenic plants displayed the alleviated wilting or chlorosis phenotype under drought and salt stresses, with higher levels of stress-induced osmotic substances like proline and higher transcript levels of the stress-responsive genes SlAREB, SlDREB2A and SlRD29. Stomatal aperature was smaller under drought stress in transgenic plants, maintaining higher water content in leaves compared with wild-type plants. The oxidative pressure, indicated by the concentration of hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA), was also reduced in transgenic plants, where we also observed higher levels of antioxidant enzyme activities under stress. Overall, our results suggest that SlWRKY8 functions as a positive regulator in plant immunity against pathogen infection as well as in plant responses to drought and salt stresses.


Assuntos
Resistência à Doença , Secas , Doenças das Plantas/genética , Proteínas de Plantas/genética , Salinidade , Solanum lycopersicum/genética , Fatores de Transcrição/genética , Regulação da Expressão Gênica de Plantas , Humanos , Solanum lycopersicum/microbiologia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Plantas Geneticamente Modificadas , Estresse Fisiológico
4.
J Pineal Res ; 67(4): e12611, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31541591

RESUMO

Melatonin has been previously shown to prevent nonalcoholic fatty liver disease (NAFLD), yet the underlying mechanisms are poorly understood. Here, we identified a previously unknown regulatory action of melatonin on apoptosis signal-regulating kinase 1 (ASK1) signaling pathway in the pathogenesis and development of NAFLD. Although melatonin administration did not alter food intake, it significantly alleviated fatty liver phenotypes, including the body weight gain, insulin resistance, hepatic lipid accumulation, steatohepatitis, and fibrosis in a high-fat diet (HFD)-induced NAFLD mouse model (in vivo). The protection of melatonin against NAFLD was not affected by inactivation of Kupffer cell in this model. In NAFLD mice liver, ASK1 signal cascade was substantially activated, evidence by the enhancement of total ASK1, phospho-ASK1, phospho-MKK3/6, phospho-p38, phospho-MKK4/7, and phospho-JNK. Melatonin treatment significantly suppressed the ASK1 upregulation and the phosphorylation of ASK1, MKK3/6, MKK4/7, p38, and JNK. Mechanistically, we found that lipid stress triggered the interaction between ASK1 and TNF receptor-associated factors (TRAFs), including TRAF1, TRAF2, and TRAF6, which resulted in ASK1 deubiquitination and thereby increased ASK1 protein stability. Melatonin did not alter ASK1 mRNA level; however, it activated a scaffold protein ß-arrestin-1 and enabled it to bind to ASK1, which antagonized the TRAFs-mediated ASK1 deubiquitination, and thus reduced ASK1 protein stability. Consistent with these findings, knockout of ß-arrestin-1 in mice partly abolished the protection of melatonin against NAFLD. Taken together, our results for the first time demonstrate that melatonin safeguards against NAFLD by eliminating ASK1 activation via inhibiting TRAFs-mediated ASK1 deubiquitination and stabilization in a ß-arrestin-1 dependent manner.


Assuntos
MAP Quinase Quinase Quinase 5/metabolismo , Melatonina/farmacologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/metabolismo , Ubiquitinação/efeitos dos fármacos , beta-Arrestina 1/metabolismo , Animais , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Estabilidade Enzimática/efeitos dos fármacos , Estabilidade Enzimática/genética , MAP Quinase Quinase Quinase 5/genética , Masculino , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/genética , Ubiquitinação/genética , beta-Arrestina 1/genética
5.
Cell Death Differ ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39009654

RESUMO

Dysregulated metabolism, cell death, and inflammation contribute to the development of metabolic dysfunction-associated steatohepatitis (MASH). Pyroptosis, a recently identified form of programmed cell death, is closely linked to inflammation. However, the precise role of pyroptosis, particularly gasdermin-E (GSDME), in MASH development remains unknown. In this study, we observed GSDME cleavage and GSDME-associated interleukin-1ß (IL-1ß)/IL-18 induction in liver tissues of MASH patients and MASH mouse models induced by a choline-deficient high-fat diet (CDHFD) or a high-fat/high-cholesterol diet (HFHC). Compared with wild-type mice, global GSDME knockout mice exhibited reduced liver steatosis, steatohepatitis, fibrosis, endoplasmic reticulum stress, lipotoxicity and mitochondrial dysfunction in CDHFD- or HFHC-induced MASH models. Moreover, GSDME knockout resulted in increased energy expenditure, inhibited intestinal nutrient absorption, and reduced body weight. In the mice with GSDME deficiency, reintroduction of GSDME in myeloid cells-rather than hepatocytes-mimicked the MASH pathologies and metabolic dysfunctions, as well as the changes in the formation of neutrophil extracellular traps and hepatic macrophage/monocyte subclusters. These subclusters included shifts in Tim4+ or CD163+ resident Kupffer cells, Ly6Chi pro-inflammatory monocytes, and Ly6CloCCR2loCX3CR1hi patrolling monocytes. Integrated analyses of RNA sequencing and quantitative proteomics revealed a significant GSDME-dependent reduction in citrullination at the arginine-114 (R114) site of dynamin-related protein 1 (Drp1) during MASH. Mutation of Drp1 at R114 reduced its stability, impaired its ability to redistribute to mitochondria and regulate mitophagy, and ultimately promoted its degradation under MASH stress. GSDME deficiency reversed the de-citrullination of Drp1R114, preserved Drp1 stability, and enhanced mitochondrial function. Our study highlights the role of GSDME in promoting MASH through regulating pyroptosis, Drp1 citrullination-dependent mitochondrial function, and energy balance in the intestine and liver, and suggests that GSDME may be a potential therapeutic target for managing MASH.

6.
Cell Death Differ ; 30(2): 457-474, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36477078

RESUMO

Smooth muscle cell (SMC) phenotypic switch from a quiescent 'contractile' phenotype to a dedifferentiated and proliferative state underlies the development of cardiovascular diseases (CVDs); however, our understanding of the mechanism is still incomplete. In the present study, we explored the potential role of ferroptosis, a novel nonapoptotic form of cell death, in SMC phenotypic switch and related neointimal formation. We found that ferroptotic stress was triggered in cultured dedifferentiated SMCs and arterial neointimal tissue of wire-injured mice. Moreover, pro-ferroptosis stress was activated in arterial neointimal tissue of clinical patients who underwent carotid endarterectomy. Blockade of ferroptotic stress via administration of a pharmacological inhibitor or by global genetic overexpression of glutathione peroxidase-4 (GPX4), a well-established anti-ferroptosis molecule, delayed SMC phenotype switch and arterial remodelling. Conditional SMC-specific gene delivery of GPX4 using adreno-associated virus in the carotid artery inhibited ferroptosis and prevented neointimal formation. Conversely, ferroptosis stress directly triggered dedifferentiation of SMCs. Transcriptomics analysis demonstrated that inhibition of ferroptotic stress mainly targets the mitochondrial respiratory chain and oxidative phosphorylation. Mechanistically, ferroptosis inhibition corrected the disrupted mitochondrial homeostasis in dedifferentiated SMCs, including enhanced mitochondrial ROS production, dysregulated mitochondrial dynamics, and mitochondrial hyperpolarization, and ultimately inhibited SMC phenotypic switch and growth. Copper-diacetyl-bisN4-methylthiosemicarbazone (CuATSM), an agent used for clinical molecular imaging and that potently inhibits ferroptosis, prevented SMC phenotypic switch, neointimal formation and arterial inflammation in mice. These results indicate that pro-ferroptosis stress is likely to promote SMC phenotypic switch during neointimal formation and imply that inhibition of ferroptotic stress may be a promising translational approach to treat CVDs with SMC phenotype switch.


Assuntos
Desdiferenciação Celular , Miócitos de Músculo Liso , Camundongos , Animais , Células Cultivadas , Homeostase , Miócitos de Músculo Liso/metabolismo , Músculo Liso , Proliferação de Células
7.
Environ Sci Pollut Res Int ; 29(47): 71427-71438, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35597826

RESUMO

Few reports have investigated the predictive value of urinary cadmium (UCd) and telomere length on renal function impairment. Therefore, we constructed nomogram models, using a cross-sectional survey to analyze the potential function of UCd and telomere length in renal function impairment risk. We randomly selected two community populations in Shanxi, China, and general information of the subjects was collected through face-to-face questionnaire surveys. Venous blood of subjects was collected to detect absolute telomere length (ATL) by real-time quantitative chain reaction (RT-PCR). Collecting urinary samples detected UCd and urinary N-acetyl-ß-d-glucosaminidase (UNAG). Estimated glomerular filtration rate (eGFR) was obtained based on serum creatinine (SCr). Nomogram models on risk prediction analysis of renal function impairment was constructed. After adjusting for other confounding factors, UCd (ß = 0.853, 95% confidence interval (CI): 0.739 ~ 0.986) and ATL (ß = 1.803, 95%CI: 1.017 ~ 1.154) were independent risk influencing factors for increased UNAG levels, and the risk factors for eGFR reduction were UCd (ß = 1.011, 95%CI: 1.187 ~ 1.471), age (ß = 1.630, 95%CI: 1.303 ~ 2.038), and sex (ß = 0.181, 95%CI: 0.105 ~ 0.310). Using UCd, ATL, sex, and age to construct the nomogram, and the C-statistics 0.584 (95%CI: 0.536 ~ 0.632) and 0.816 (95%CI: 0.781 ~ 0.851) were obtained by internal verification of the calibration curve, C-statistics revealed nomogram model validation was good and using decision curve analysis (DCA) confirmed a good predictive value of the nomogram models. In a nomogram model, ATL, UCd, sex, and age were detected as independent risk factors for renal function impairment, with UCd being the strongest predictor.


Assuntos
Cádmio , Insuficiência Renal , Acetilglucosaminidase/urina , Cádmio/toxicidade , Cádmio/urina , China , Creatinina , Estudos Transversais , Feminino , Humanos , Rim/fisiologia , Masculino , Insuficiência Renal/induzido quimicamente , Telômero
8.
Toxicology ; 465: 153012, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34718030

RESUMO

Rare earth elements (REEs) are widely used in the industry, agriculture, biomedicine, aerospace, etc, and have been shown to pose toxic effects on animals, as such, studies focusing on their biomedical properties are gaining wide attention. However, environmental and population health risks of REEs are still not very clear. Also, the REEs damage to the nervous system and related molecular mechanisms needs further research. In this study, the L1 and L4 stages of the model organism Caenorhabditis elegans were used to evaluate the effects and possible neurotoxic mechanism of lanthanum(III) nitrate hexahydrate (La(NO3)3·6H2O). For the L1 and L4 stage worms, the 48-h median lethal concentrations (LC50s) of La(NO3)3·6H2O were 93.163 and 648.0 mg/L respectively. Our results show that La(NO3)3·6H2O induces growth inhibition and defects in behavior such as body length, body width, body bending frequency, head thrashing frequency and pharyngeal pumping frequency at the L1 and L4 stages in C. elegans. The L1 stage is more sensitive to the toxicity of lanthanum than the L4 stage worms. Using transgenic strains (BZ555, EG1285 and NL5901), we found that La(NO3)3·6H2O caused the loss or break of soma and dendrite neurons in L1 and L4 stages; and α-synuclein aggregation in L1 stage, indicating that Lanthanum can cause toxic damage to dopaminergic and GABAergic neurons. Mechanistically, La(NO3)3·6H2O exposure inhibited or activated the neurotransmitter transporters and receptors (glutamate, serotonin and dopamine) in C. elegans, which regulate behavior and movement functions. Furthermore, significant increase in the production of reactive oxygen species (ROS) was found in the L4 stage C. elegans exposed to La(NO3)3·6H2O. Altogether, our data show that exposure to lanthanum can cause neuronal toxic damage and behavioral defects in C. elegans, and provide basic information for understanding the neurotoxic effect mechanism and environmental health risks of rare earth elements.


Assuntos
Comportamento Animal/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios GABAérgicos/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Lantânio/toxicidade , Síndromes Neurotóxicas/etiologia , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Relação Dose-Resposta a Droga , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/patologia , Dose Letal Mediana , Movimento/efeitos dos fármacos , Síndromes Neurotóxicas/genética , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Espécies Reativas de Oxigênio/metabolismo , Medição de Risco , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
9.
Int J Antimicrob Agents ; 57(3): 106281, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33465459

RESUMO

The aim of this study was to investigate the pharmacokinetics of colistin in cerebrospinal fluid (CSF) after intraventricular (IVT) administration of colistin methanesulfonate (CMS) for central nervous system (CNS) infections caused by multidrug-resistant Gram-negative bacteria. Ten patients with CNS infection were treated with CMS (active substance colistin equivalent to 100 000 units, every 24 h) by IVT administration. After 3 days of treatment, the concentration of colistin in the CSF was determined by selective ultra-performance liquid chromatography (UPLC) at 2, 4, 6, 8, 12 and 24 h after CMS administration. A pharmacokinetic analysis was performed using Phoenix WinNonlin. Following IVT administration of CMS, the estimated colistin apparent CSF half-life (t1/2) was 10.46 ± 6.98 h, the average peak colistin concentration (Cmax) was 16.95 ± 7.39 µg/mL and the average time to peak concentration (Tmax) was 4.6 ± 0.97 h. The measured trough concentration (Cmin; colistin concentration in CSF at 24 h after administration of CMS) was 1.12-8.33 µg/mL and the average Cmin was 2.91 ± 2.11 µg/mL. CSF concentrations of colistin were above the minimum inhibitory concentration (MIC) of 0.5 µg/mL at 24 h after IVT administration in all patients. Microbiological cure was observed in all patients. In conclusion, this is the first study of colistin pharmacokinetics in CSF after IVT administration alone in patients with CNS infection. It provides essential data for designing relatively safe and effective CMS dosing regimens.


Assuntos
Infecções Bacterianas do Sistema Nervoso Central/tratamento farmacológico , Colistina/administração & dosagem , Colistina/farmacocinética , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Adolescente , Adulto , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Infecções Bacterianas do Sistema Nervoso Central/microbiologia , Líquido Cefalorraquidiano/química , Farmacorresistência Bacteriana Múltipla , Feminino , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Injeções Intraventriculares , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Adulto Jovem
10.
Br J Pharmacol ; 178(10): 2111-2130, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32037512

RESUMO

BACKGROUND AND PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is a worldwide public health problem with no established pharmacological therapy. Here, we explored the potential benefit of P7C3-A20, a novel aminopropyl carbazole compound with neuroprotective activity, in a NAFLD model, induced in mice by a high-fat diet (HFD). EXPERIMENTAL APPROACH: C57BL/6J mice were given a HFD (42% fat content) for 16 weeks to induce NAFLD. P7C3-A20 (20 mg·kg-1 ·day-1 ) was given by gavage for 2 weeks. Indirect calorimetry, histological analysis, immunoblotting, immunohistochemistry, and biomedical examinations were performed. Gut microbiota were determined using a 16S ribosomal RNA sequencing analysis. KEY RESULTS: P7C3-A20 treatment reduced body weight gain/adiposity, improved insulin resistance, promoted energy expenditure (O2 consumption/CO2 production), inhibited lipid oxidation, suppressed hepatic inflammation (Kupffer cell number and pro-inflammatory factors), decreased necroptosis/apoptosis (receptor-interacting protein kinase 3, cleaved caspase-3, and TUNEL), and alleviated liver fibrosis and injury. Mechanistically, P7C3-A20 stimulated FGF21 and FGF1 via activating liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), which further resulted in a reduced nuclear translocation of CREB-regulated transcription coactivator 2 (CRTC2). In AMPKα2 knockout mice, the protection of P7C3-A20 against HFD-induced metabolism abnormalities and fat accumulation, as well as the elevation of blood FGF21 and FGF1, was abolished. P7C3-A20 increased the gut microbiota species richness. Moreover, it enhanced the proportions of Akkermansia, Lactobacillus, and Prevotellaceae, while reducing the proportions of Enterobacteriaceae, Escherichia, and Parasutterella. CONCLUSIONS AND IMPLICATIONS: P7C3-A20 increased levels of NAD+ and alleviated NAFLD through stimulating FGF21 and FGF1 in an LKB1/AMPK/CRTC2-dependent manner and shaping gut microbiota. LINKED ARTICLES: This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc.


Assuntos
Carbazóis/farmacologia , Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Proteínas Quinases Ativadas por AMP , Animais , Dieta Hiperlipídica , Fator 1 de Crescimento de Fibroblastos , Fatores de Crescimento de Fibroblastos , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico
11.
Theranostics ; 11(9): 4381-4402, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33754067

RESUMO

Rationale: Nicotinamide adenine dinucleotide+ (NAD+)-boosting therapy has emerged as a promising strategy to treat various health disorders, while the underlying molecular mechanisms are not fully understood. Here, we investigated the involvement of fibronectin type III domain containing 5 (Fndc5) or irisin, which is a novel exercise-linked hormone, in the development and progression of nonalcoholic fatty liver disease (NAFLD). Methods: NAD+-boosting therapy was achieved by administrating of nicotinamide riboside (NR) in human and mice. The Fndc5/irisin levels in tissues and blood were measured in NR-treated mice or human volunteers. The therapeutic action of NR against NAFLD pathologies induced by high-fat diet (HFD) or methionine/choline-deficient diet (MCD) were compared between wild-type (WT) and Fndc5-/- mice. Recombinant Fndc5/irisin was infused to NALFD mice via osmotic minipump to test the therapeutic action of Fndc5/irisin. Various biomedical experiments were conducted in vivo and in vitro to know the molecular mechanisms underlying the stimulation of Fndc5/irisin by NR treatment. Results: NR treatment elevated plasma level of Fndc5/irisin in mice and human volunteers. NR treatment also increased Fndc5 expression in skeletal muscle, adipose and liver tissues in mice. In HFD-induced NAFLD mice model, NR displayed remarkable therapeutic effects on body weight gain, hepatic steatosis, steatohepatitis, insulin resistance, mitochondrial dysfunction, apoptosis and fibrosis; however, these actions of NR were compromised in Fndc5-/- mice. Chronic infusion of recombinant Fndc5/irisin alleviated the NAFLD pathological phenotypes in MCD-induced NAFLD mice model. Mechanistically, NR reduced the lipid stress-triggered ubiquitination of Fndc5, which increased Fndc5 protein stability and thus enhanced Fndc5 protein level. Using shRNA-mediated knockdown screening, we found that NAD+-dependent deacetylase SIRT2, rather than other sirtuins, interacts with Fndc5 to decrease Fndc5 acetylation, which reduces Fndc5 ubiquitination and stabilize it. Treatment of AGK2, a selective inhibitor of SIRT2, blocked the therapeutic action of NR against NAFLD pathologies and NR-induced Fndc5 deubiquitination/deacetylation. At last, we identified that the lysine sites K127/131 and K185/187/189 of Fndc5 may contribute to the SIRT2-dependent deacetylation and deubiquitination of Fndc5. Conclusions: The findings from this research for the first time demonstrate that NAD+-boosting therapy reverses NAFLD by regulating SIRT2-deppendent Fndc5 deacetylation and deubiquitination, which results in a stimulation of Fndc5/irisin, a novel exerkine. These results suggest that Fndc5/irisin may be a potential nexus between physical exercise and NAD+-boosting therapy in metabolic pathophysiology.


Assuntos
Fibronectinas/metabolismo , NAD/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Tecido Adiposo/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Resistência à Insulina/fisiologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/metabolismo , Ubiquitinação/fisiologia
12.
SLAS Discov ; 22(9): 1162-1167, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28783476

RESUMO

A crude extract from earthworms was used as an environmentally friendly and easily accessible biocatalyst for asymmetric direct aldol reactions. The ß-hydroxy carbonyl compounds could be prepared in yields of up to 94%, with ee values of up to 98% and dr of up to >99:1. A wide range of substrates could participate in the reaction. This earthworm catalyst was also efficient in the large-scale reaction, providing product in excellent yield and good selectivity. The protocol as an example gives inspiration for the development of sustainable catalysts from nature, which also provides a potential possibility for application of earthworm catalyst in industrial production.

13.
Ultrasound Q ; 31(2): 124-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25364962

RESUMO

OBJECTIVE: The current study used exploration during radical resection, which reveals the vascular lesion directly, as a criterion standard to evaluate and compare sonography and computed tomography (CT) diagnosis. METHODS: A total of 70 patients (47 men and 23 women) with Budd-Chiari syndrome who underwent radical resection at Peking University People's Hospital between 2006 and 2012 were retrospectively examined. Sonography and CT were performed in all patients preoperatively. The lesions were classified into 6 groups on the basis of the intraoperative findings. RESULTS: When compared with the surgical findings, sonography was significantly more accurate than CT (91.4% vs 77.1%, respectively; P = 0.035) in detecting membranous lesions with thrombosis of the inferior vena cava. Moreover, sonography was significantly more accurate than CT (80.0% vs 55.7%, respectively; P = 0.000) in detecting membranous lesions in hepatic vein openings and short-segment lesions (<1 cm) comprising thrombosis and fibrous tissue without the membrane in hepatic openings (87.1% vs 71.4%, respectively; P = 0.036). CONCLUSIONS: By using exploration during radical resection as the criterion standard to assess imaging modalities for Budd-Chiari syndrome, we found that sonography was advantageous over CT not only in detecting membranous lesions with inferior vena cava thrombosis but also in diagnosing lesions in hepatic vein openings.


Assuntos
Síndrome de Budd-Chiari/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Síndrome de Budd-Chiari/cirurgia , Meios de Contraste , Feminino , Veias Hepáticas/diagnóstico por imagem , Veias Hepáticas/cirurgia , Humanos , Iohexol/análogos & derivados , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Masculino , Intensificação de Imagem Radiográfica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Trombose/diagnóstico por imagem , Trombose/cirurgia , Ultrassonografia Doppler em Cores , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/cirurgia
14.
Phytochemistry ; 60(7): 675-81, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12127584

RESUMO

A(4) polypeptide-containing (Shirotsurunoko and York) and A(4) polypeptide-lacking (Raiden and Suzuyutaka) soybean cultivars were used to investigate the heterogeneity of glycinin molecular species. Purification of glycinin by DEAE-Toyopearl column chromatography afforded molecular species eluting before the glycinin fraction. Analysis of this fraction by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and sucrose density gradient centrifugation indicated that this protein consisted of A(1) and A(2) polypeptides. The A(4)-containing soybean cultivars contained less of this protein than the A(4)-lacking soybean cultivars, as exhibited by the size of the early peak appearing during column chromatography. Alkaline PAGE and N-terminal amino acid sequence analysis confirmed that the A(1)- and A(2)-rich molecular species in the A(4) polypeptide-lacking cultivars consisted of the A(1a) and A(2) polypeptides. Estimation of the molecular mass by gel permeation chromatography and multi-angle laser light scattering (GPC-MALLS) indicated that the A(1a)- and A(2)-rich molecular species were similar to a monomer of glycinin.


Assuntos
Globulinas/isolamento & purificação , Glycine max/química , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Globulinas/química , Peso Molecular , Proteínas de Soja
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