Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.071
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 165(2): 421-33, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26949185

RESUMO

The mitochondrial pathway of apoptosis is initiated by mitochondrial outer membrane permeabilization (MOMP). The BCL-2 family effectors BAX and BAK are thought to be absolutely required for this process. Here, we report that BCL-2 ovarian killer (BOK) is a bona fide yet unconventional effector of MOMP that can trigger apoptosis in the absence of both BAX and BAK. However, unlike the canonical effectors, BOK appears to be constitutively active and unresponsive to antagonistic effects of the antiapoptotic BCL-2 proteins. Rather, BOK is controlled at the level of protein stability by components of the endoplasmic reticulum (ER)-associated degradation pathway. BOK is ubiquitylated by the AMFR/gp78 E3 ubiquitin ligase complex and targeted for proteasomal degradation in a VCP/p97-dependent manner, which allows survival of the cell. When proteasome function, VCP, or gp78 activity is compromised, BOK is stabilized to induce MOMP and apoptosis independently of other BCL-2 proteins.


Assuntos
Apoptose , Degradação Associada com o Retículo Endoplasmático , Membranas Mitocondriais/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Retículo Endoplasmático/metabolismo , Fibroblastos/metabolismo , Humanos , Camundongos , Permeabilidade , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética
2.
Nature ; 586(7831): 735-740, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32879487

RESUMO

Innate immunity is associated with Alzheimer's disease1, but the influence of immune activation on the production of amyloid-ß is unknown2,3. Here we identify interferon-induced transmembrane protein 3 (IFITM3) as a γ-secretase modulatory protein, and establish a mechanism by which inflammation affects the generation of amyloid-ß. Inflammatory cytokines induce the expression of IFITM3 in neurons and astrocytes, which binds to γ-secretase and upregulates its activity, thereby increasing the production of amyloid-ß. The expression of IFITM3 is increased with ageing and in mouse models that express familial Alzheimer's disease genes. Furthermore, knockout of IFITM3 reduces γ-secretase activity and the formation of amyloid plaques in a transgenic mouse model (5xFAD) of early amyloid deposition. IFITM3 protein is upregulated in tissue samples from a subset of patients with late-onset Alzheimer's disease that exhibit higher γ-secretase activity. The amount of IFITM3 in the γ-secretase complex has a strong and positive correlation with γ-secretase activity in samples from patients with late-onset Alzheimer's disease. These findings reveal a mechanism in which γ-secretase is modulated by neuroinflammation via IFITM3 and the risk of Alzheimer's disease is thereby increased.


Assuntos
Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Imunidade Inata , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo , Idade de Início , Idoso de 80 Anos ou mais , Envelhecimento/genética , Envelhecimento/imunologia , Envelhecimento/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/química , Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Astrócitos/metabolismo , Domínio Catalítico , Modelos Animais de Doenças , Feminino , Células HEK293 , Humanos , Inflamação , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Presenilina-1/metabolismo , Proteínas de Ligação a RNA/genética , Risco , Regulação para Cima
3.
Nat Chem Biol ; 19(12): 1448-1457, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37322156

RESUMO

Autophagy is a cellular process with important functions that drive neurodegenerative diseases and cancers. Lysosomal hyperacidification is a hallmark of autophagy. Lysosomal pH is currently measured by fluorescent probes in cell culture, but existing methods do not allow for quantitative, transient or in vivo measurements. In the present study, we developed near-infrared optical nanosensors using organic color centers (covalent sp3 defects on carbon nanotubes) to measure autophagy-mediated endolysosomal hyperacidification in live cells and in vivo. The nanosensors localize to the lysosomes, where the emission band shifts in response to local pH, enabling spatial, dynamic and quantitative mapping of subtle changes in lysosomal pH. Using the sensor, we observed cellular and intratumoral hyperacidification on administration of mTORC1 and V-ATPase modulators, revealing that lysosomal acidification mirrors the dynamics of S6K dephosphorylation and LC3B lipidation while diverging from p62 degradation. This sensor enables the transient and in vivo monitoring of the autophagy-lysosomal pathway.


Assuntos
Nanotubos de Carbono , Autofagia/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Lisossomos/metabolismo , Concentração de Íons de Hidrogênio
4.
Mol Psychiatry ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383769

RESUMO

CD33 is a transmembrane receptor expressed on cells of myeloid lineage and regulates innate immunity. CD33 is a risk factor for Alzheimer's disease (AD) and targeting CD33 has been a promising strategy drug development. However, the mechanism of CD33's action is poorly understood. Here we investigate the mechanism of anti-CD33 antibody HuM195 (Lintuzumab) and its single-chain variable fragment (scFv) and examine their therapeutic potential. Treatment with HuM195 full-length antibody or its scFv increased phagocytosis of ß-amyloid 42 (Aß42) in human microglia and monocytes. This activation of phagocytosis was driven by internalization and degradation of CD33, thereby downregulating its inhibitory signal. HumM195 transiently induced CD33 phosphorylation and its signaling via receptor dimerization. However, this signaling decayed with degradation of CD33. scFv binding to CD33 leads to a degradation of CD33 without detection of the CD33 dimerization and signaling. Moreover, we found that treatments with either HuM195 or scFv promotes the secretion of IL33, a cytokine implicated in microglia reprogramming. Importantly, recombinant IL33 potentiates the uptake of Aß42 in monocytes. Collectively, our findings provide unanticipated mechanistic insight into the role of CD33 signaling in both monocytes and microglia and define a molecular basis for the development of CD33-based therapy of AD.

5.
J Lipid Res ; 65(2): 100499, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38218337

RESUMO

Ferroptosis is a novel cell death mechanism that is mediated by iron-dependent lipid peroxidation. It may be involved in atherosclerosis development. Products of phospholipid oxidation play a key role in atherosclerosis. 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) is a phospholipid oxidation product present in atherosclerotic lesions. It remains unclear whether PGPC causes atherosclerosis by inducing endothelial cell ferroptosis. In this study, human umbilical vein endothelial cells (HUVECs) were treated with PGPC. Intracellular levels of ferrous iron, lipid peroxidation, superoxide anions (O2•-), and glutathione were detected, and expression of fatty acid binding protein-3 (FABP3), glutathione peroxidase 4 (GPX4), and CD36 were measured. Additionally, the mitochondrial membrane potential (MMP) was determined. Aortas from C57BL6 mice were isolated for vasodilation testing. Results showed that PGPC increased ferrous iron levels, the production of lipid peroxidation and O2•-, and FABP3 expression. However, PGPC inhibited the expression of GPX4 and glutathione production and destroyed normal MMP. These effects were also blocked by ferrostatin-1, an inhibitor of ferroptosis. FABP3 silencing significantly reversed the effect of PGPC. Furthermore, PGPC stimulated CD36 expression. Conversely, CD36 silencing reversed the effects of PGPC, including PGPC-induced FABP3 expression. Importantly, E06, a direct inhibitor of the oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine IgM natural antibody, inhibited the effects of PGPC. Finally, PGPC impaired endothelium-dependent vasodilation, ferrostatin-1 or FABP3 inhibitors inhibited this impairment. Our data demonstrate that PGPC impairs endothelial function by inducing endothelial cell ferroptosis through the CD36 receptor to increase FABP3 expression. Our findings provide new insights into the mechanisms of atherosclerosis and a therapeutic target for atherosclerosis.


Assuntos
Aterosclerose , Cicloexilaminas , Ferroptose , Fenilenodiaminas , Animais , Camundongos , Humanos , Fosfolipídeos , Fosforilcolina , Éteres Fosfolipídicos/metabolismo , Éteres Fosfolipídicos/farmacologia , Camundongos Endogâmicos C57BL , Células Endoteliais da Veia Umbilical Humana/metabolismo , Endotélio/metabolismo , Glutationa/metabolismo , Ferro/metabolismo , Proteína 3 Ligante de Ácido Graxo
6.
Mol Cancer ; 23(1): 48, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459558

RESUMO

BACKGROUND: Pancreatic adenocarcinoma (PC) is an aggressive malignancy with limited treatment options. The poor prognosis primarily stems from late-stage diagnosis and when the disease has become therapeutically challenging. There is an urgent need to identify specific biomarkers for cancer subtyping and early detection to enhance both morbidity and mortality outcomes. The addition of the EGFR tyrosine kinase inhibitor (TKI), erlotinib, to gemcitabine chemotherapy for the first-line treatment of patients with advanced pancreatic cancer slightly improved outcomes. However, restricted clinical benefits may be linked to the absence of well-characterized criteria for stratification and dependable biomarkers for the prediction of treatment effectiveness. METHODS AND RESULTS: We examined the levels of various cancer hallmarks and identified glycolysis as the primary risk factor for overall survival in PC. Subsequently, we developed a glycolysis-related score (GRS) model to accurately distinguish PC patients with high GRS. Through in silico screening of 4398 compounds, we discovered that erlotinib had the strongest therapeutic benefits for high-GRS PC patients. Furthermore, we identified ARNTL2 as a novel prognostic biomarker and a predictive factor for erlotinib treatment responsiveness in patients with PC. Inhibition of ARNTL2 expression reduced the therapeutic efficacy, whereas increased expression of ARNTL2 improved PC cell sensitivity to erlotinib. Validation in vivo using patient-derived xenografts (PDX-PC) with varying ARNTL2 expression levels demonstrated that erlotinib monotherapy effectively halted tumor progression in PDX-PC models with high ARNTL2 expression. In contrast, PDX-PC models lacking ARNTL2 did not respond favorably to erlotinib treatment. Mechanistically, we demonstrated that the ARNTL2/E2F1 axis-mediated cellular glycolysis sensitizes PC cells to erlotinib treatment by activating the PI3K/AKT signaling pathway. CONCLUSIONS: Our investigations have identified ARNTL2 as a novel prognostic biomarker and predictive indicator of sensitivity. These results will help to identify erlotinib-responsive cases of PC and improve treatment outcomes. These findings contribute to the advancement of precision oncology, enabling more accurate and targeted therapeutic interventions.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , Neoplasias Pancreáticas , Humanos , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Fatores de Transcrição ARNTL/metabolismo , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Cloridrato de Erlotinib/farmacologia , Neoplasias Pulmonares/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Medicina de Precisão , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
7.
Apoptosis ; 29(1-2): 86-102, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37752371

RESUMO

In recent years, colorectal cancer incidence and mortality have increased significantly due to poor lifestyle choices. Despite the development of various treatments, their effectiveness against advanced/metastatic colorectal cancer remains unsatisfactory due to drug resistance. However, ferroptosis, a novel iron-dependent cell death process induced by lipid peroxidation and elevated reactive oxygen species (ROS) levels along with reduced activity of the glutathione peroxidase 4 (GPX4) antioxidant enzyme system, shows promise as a therapeutic target for colorectal cancer. This review aims to delve into the regulatory mechanisms of ferroptosis in colorectal cancer, providing valuable insights into potential therapeutic approaches. By targeting ferroptosis, new avenues can be explored for innovative therapies to combat colorectal cancer more effectively. In addition, understanding the molecular pathways involved in ferroptosis may help identify biomarkers for prognosis and treatment response, paving the way for personalized medicine approaches. Furthermore, exploring the interplay between ferroptosis and other cellular processes can uncover combination therapies that enhance treatment efficacy. Investigating the tumor microenvironment's role in regulating ferroptosis may offer strategies to sensitize cancer cells to cell death induction, leading to improved outcomes. Overall, ferroptosis presents a promising avenue for advancing the treatment of colorectal cancer and improving patient outcomes.


Assuntos
Neoplasias Colorretais , Ferroptose , Humanos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/farmacologia , Ferroptose/genética , Apoptose , Ferro/metabolismo , Peroxidação de Lipídeos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Microambiente Tumoral
8.
J Med Virol ; 96(7): e29776, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38953430

RESUMO

The genetic diversity of killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) genes influences the host's immune response to viral pathogens. This study aims to explore the impact of five single nucleotide polymorphisms (SNPs) in KIR3DL2 and HLA-A genes on hepatitis C virus (HCV) infection. A total of 2251 individuals were included in the case-control study. SNPs including KIR3DL2 rs11672983, rs3745902, rs1654644, and HLA-A rs3869062, rs12202296 were genotyped. By controlling various confounding factors using a modified logistic regression model, as well as incorporating stratified analysis, joint effects analysis, and multidimensional bioinformatics analysis, we analyzed the relationship between SNPs and HCV infection. The logistic regression analysis showed a correlation between KIR3DL2 rs11672983 AA, KIR3DL2 rs3745902 TT, and increased HCV susceptibility (p < 0.01). Stratified analysis indicated that KIR3DL2 rs1654644 and HLA-A rs3869062 also heightened HCV susceptibility in certain subgroups. A linear trend of rising HCV infection rates was observed when combining KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT (ptrend = 0.007). Bioinformatics analysis suggested these SNPs' regulatory potential and their role in altering messenger RNA secondary structure, implying their functional relevance in HCV susceptibility. Our findings indicate that KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT are significantly associated with increased susceptibility to HCV infection.


Assuntos
Predisposição Genética para Doença , Genótipo , Hepatite C , Polimorfismo de Nucleotídeo Único , Humanos , Masculino , Feminino , Estudos de Casos e Controles , Hepatite C/genética , Hepatite C/virologia , Hepatite C/imunologia , Pessoa de Meia-Idade , Adulto , Antígenos HLA-A/genética , Hepacivirus/genética , Hepacivirus/imunologia , Receptores KIR/genética , Idoso , Receptores KIR3DL2/genética
9.
Chemistry ; 30(27): e202304118, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38433408

RESUMO

New chiral ligands could be obtained by introducing proline moieties and imidazoline moieties to binaphthyl skeletons. The chiral ligands exhibited balanced rigidity and flexibility which could allow the change of the conformations during the reactions on one hand, and could provide sufficient asymmetric induction on the other. The proline moiety could act as a linker connecting the binaphthyl skeletons and the imidazoline moieties as well as a coordinating group for the central metal, and the electronic and steric properties of the imidazoline groups could be carefully fine-tuned by the use of different substituents. In the presence of Cu(II) catalyst bearing such chiral ligands, aza-Friedel-Crafts reaction of 1-naphthols and electron-rich phenols with isatin-derived ketimines provided the desired products with good to excellent yields and up to 99 % ee. The reactions showed good scalability, and excellent ee could still be obtained when the reaction was carried out in gram-scale.

10.
Exp Eye Res ; 238: 109715, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37951338

RESUMO

This study aimed to examine the intraocular tolerability of the epidermal growth factor receptor antibody cetuximab, when applied intravitreally, and its effect on axial elongation. Guinea pigs aged 2-3 weeks were subjected to bilateral plano glasses and bilateral lens-induced myopization (LIM) as a single procedure for group I (n = 8) and group II (n = 8), respectively. In the animals of group III (n = 8), group IV (n = 8), and group V (n = 8), the right eyes of the animals, in addition to LIM, received four weekly intravitreal injections of cetuximab (Erbitux®) in doses of 6.25 µg, 12.5 µg, and 25 µg, respectively. As controls, the left eyes, in addition to LIM, received corresponding intraocular injections of phosphate-buffered saline. The animals underwent regular ophthalmoscopic examinations and biometry for axial length measurements. With increasing doses of cetuximab, the inter-eye difference in axial elongation (at study end, left eyes minus right eyes) were significantly the smallest in group I (0.00 ± 0.02 mm) and group II (-0.01 ± 0.02 mm), they were larger in group III (0.04 ± 0.04 mm) and group IV (0.10 ± 0.03 mm), and they were the largest in group V (0.11 ± 0.01 mm). The inter-eye difference in axial elongation enlarged (P < 0.001) with the number of injections applied. Retinal thickness at the posterior pole (right eyes) was significantly thicker in group V than in group II (P < 0.01). The density of apoptotic cells (visualized by TUNEL-staining) did not vary significantly between any of the groups (all P > 0.05). The results suggest that intravitreal injections of cetuximab in young guinea pigs with LIM resulted in a reduction in axial elongation in a dose-dependent and number of treatment-dependent manner. Intraocular toxic effects, such as intraocular inflammation, retinal thinning, or an increased density of apoptotic cells in the retina, were not observed in association with the intravitreally applied cetuximab.


Assuntos
Cristalino , Miopia , Cobaias , Animais , Miopia/metabolismo , Cetuximab/toxicidade , Cetuximab/metabolismo , Retina/metabolismo , Cristalino/metabolismo , Injeções Intraoculares , Modelos Animais de Doenças
11.
Am J Nephrol ; 55(1): 1-17, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37793348

RESUMO

BACKGROUND: Mineralocorticoid receptor blockade could be a potential approach for the inhibition of chronic kidney disease (CKD) progression. The benefits and harms of different mineralocorticoid receptor antagonists (MRAs) in CKD are inconsistent. OBJECTIVES: The aim of the study was to summarize the benefits and harms of MRAs for CKD patients. METHODS: We searched MEDLINE, EMBASE, and the Cochrane databases for trials assessing the effects of MRAs on non-dialysis-dependent CKD populations. Treatment and adverse effects were summarized using meta-analysis. RESULTS: Fifty-three trials with 6 different MRAs involving 22,792 participants were included. Compared with the control group, MRAs reduced urinary albumin-to-creatinine ratio (weighted mean difference [WMD], -90.90 mg/g, 95% CI, -140.17 to -41.64 mg/g), 24-h urinary protein excretion (WMD, -0.20 g, 95% CI, -0.28 to -0.12 g), estimated glomerular filtration rate (eGFR) (WMD, -1.99 mL/min/1.73 m2, 95% CI, -3.28 to -0.70 mL/min/1.73 m2), chronic renal failure events (RR, 0.86, 95% CI, 0.79-0.93), and cardiovascular events (RR, 0.84, 95% CI, 0.77-0.92). MRAs increased the incidence of hyperkalemia (RR, 2.04, 95% CI, 1.73-2.40) and hypotension (RR, 1.80, 95% CI, 1.41-2.31). MRAs reduced the incidence of peripheral edema (RR, 0.65, 95% CI, 0.56-0.75) but not the risk of acute kidney injury (RR, 0.94, 95% CI, 0.79-1.13). Nonsteroidal MRAs (RR, 0.66, 95% CI, 0.57-0.75) but not steroidal MRAs (RR, 0.20, 95% CI, 0.02-1.68) significantly reduced the risk of peripheral edema. Steroidal MRAs (RR, 5.68, 95% CI, 1.26-25.67) but not nonsteroidal MRAs (RR, 0.52, 95% CI, 0.22-1.22) increased the risk of breast disorders. CONCLUSIONS: In the CKD patients, MRAs, particularly in combination with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, reduced albuminuria/proteinuria, eGFR, and the incidence of chronic renal failure, cardiovascular and peripheral edema events, whereas increasing the incidence of hyperkalemia and hypotension, without the augment of acute kidney injury events. Nonsteroidal MRAs were superior in the reduction of more albuminuria with fewer peripheral edema events and without the augment of breast disorder events.


Assuntos
Injúria Renal Aguda , Hiperpotassemia , Hipotensão , Falência Renal Crônica , Insuficiência Renal Crônica , Humanos , Antagonistas de Receptores de Mineralocorticoides/efeitos adversos , Hiperpotassemia/induzido quimicamente , Hiperpotassemia/epidemiologia , Albuminúria/induzido quimicamente , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/induzido quimicamente , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/epidemiologia , Edema
12.
Langmuir ; 40(22): 11401-11410, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38767862

RESUMO

To functionalize interfaces with supported biomembranes and membrane proteins, the challenge is to build stabilized and supported systems that mimic the native lipid microenvironment. Our objective is to control substrate-to-biomembrane spacing and the tethering chemistry so proteoliposomes can be fused and conjugated without perturbation of membrane protein function. Furthermore, the substrates need to exhibit low protein and antibody nonspecific binding to use these systems in assays. We have employed protein orthogonal coupling schemes in concert with multiarm poly(ethylene glycol) (PEG) technology to build supported biomembranes on microspheres. The lipid bilayer structures and tailored substrates of the microsphere-supported biomembranes were analyzed via flow cytometry, confocal fluorescence, and super-resolution imaging microscopy, and the lateral fluidity was quantified using fluorescence recovery after photobleaching (FRAP) techniques. Under these conditions, the 4-arm-PEG20,000-NH2 based configuration gave the most desirable tethering system based on lateral diffusivity and coverage.


Assuntos
Bicamadas Lipídicas , Polietilenoglicóis , Polietilenoglicóis/química , Bicamadas Lipídicas/química , Microesferas , Recuperação de Fluorescência Após Fotodegradação , Polímeros/química
13.
J Biochem Mol Toxicol ; 38(4): e23698, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38501767

RESUMO

Accumulating evidence confirms that sleep insufficiency is a high risk factor for cognitive impairment, which involves inflammation and synaptic dysfunction. Resveratrol, an agonist of the Sirt1, has demonstrated anti-inflammation and neuroprotective effects in models of Alzheimer's disease, Parkinson's disease, and schizophrenia. However, the beneficial effects of resveratrol on sleep deprivation-induced cognitive deficits and its underlying molecular mechanisms are unclear. In the present study, thirty-two male C57BL/6 J mice were randomly divided into a Control+DMSO group, Control+Resveratrol group, SD+DMSO group, and SD+Resveratrol group. The mice in the SD+Resveratrol group underwent 5 days of sleep deprivation after pretreatment with resveratrol (50 mg/kg) for 2 weeks, while the mice in the SD+DMSO group only underwent sleep deprivation. After sleep deprivation, we evaluated spatial learning and memory function using the Morris water maze test. We used general molecular biology techniques to detect changes in levels of pro-inflammatory cytokines and Sirt1/miR-134 pathway-related synaptic plasticity proteins. We found that resveratrol significantly reversed sleep deprivation-induced learning and memory impairment, elevated interleukin-1ß, interleukin-6, and tumor necrosis factor-α levels, and decreased brain-derived neurotrophic factor, tyrosine kinase receptor B, postsynaptic density protein-95, and synaptophysin levels by activating the Sirt1/miR-134 pathway. In conclusion, resveratrol is a promising agent for preventing sleep deprivation-induced cognitive dysfunction by reducing pro-inflammatory cytokines and improving synaptic function via the Sirt1/miR-134 pathway.


Assuntos
Disfunção Cognitiva , MicroRNAs , Masculino , Camundongos , Animais , Resveratrol/farmacologia , Privação do Sono/complicações , Privação do Sono/metabolismo , Sirtuína 1/metabolismo , Dimetil Sulfóxido/metabolismo , Dimetil Sulfóxido/farmacologia , Camundongos Endogâmicos C57BL , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/prevenção & controle , Hipocampo/metabolismo , MicroRNAs/metabolismo , Citocinas/metabolismo , Cognição
14.
Mol Cell ; 64(3): 493-506, 2016 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-27773673

RESUMO

MYCN amplification in human cancers predicts poor prognosis and resistance to therapy. However, pharmacological strategies that directly target N-Myc, the protein encoded by MYCN, remain elusive. Here, we identify a molecular mechanism responsible for reciprocal activation between Polo-like kinase-1 (PLK1) and N-Myc. PLK1 specifically binds to the SCFFbw7 ubiquitin ligase, phosphorylates it, and promotes its autopolyubiquitination and proteasomal degradation, counteracting Fbw7-mediated degradation of N-Myc and additional substrates, including cyclin E and Mcl1. Stabilized N-Myc in turn directly activates PLK1 transcription, constituting a positive feedforward regulatory loop that reinforces Myc-regulated oncogenic programs. Inhibitors of PLK1 preferentially induce potent apoptosis of MYCN-amplified tumor cells from neuroblastoma and small cell lung cancer and synergistically potentiate the therapeutic efficacies of Bcl2 antagonists. These findings reveal a PLK1-Fbw7-Myc signaling circuit that underlies tumorigenesis and validate PLK1 inhibitors, alone or with Bcl2 antagonists, as potential effective therapeutics for MYC-overexpressing cancers.


Assuntos
Neoplasias Encefálicas/genética , Proteínas de Ciclo Celular/genética , Proteínas F-Box/genética , Retroalimentação Fisiológica , Regulação Neoplásica da Expressão Gênica , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Ubiquitina-Proteína Ligases/genética , Animais , Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sinergismo Farmacológico , Proteínas F-Box/metabolismo , Proteína 7 com Repetições F-Box-WD , Humanos , Camundongos Nus , Proteína Proto-Oncogênica N-Myc/antagonistas & inibidores , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/tratamento farmacológico , Neuroblastoma/mortalidade , Neuroblastoma/patologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Pteridinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Sulfonamidas/farmacologia , Análise de Sobrevida , Transcrição Gênica , Carga Tumoral/efeitos dos fármacos , Ubiquitina-Proteína Ligases/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Quinase 1 Polo-Like
15.
Eur Spine J ; 33(2): 695-705, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37874394

RESUMO

PURPOSE: Although the Roussouly classification has been widely used in surgical planning for adult scoliosis patients, little is known about whether it can be used to guide sagittal correction for adolescent idiopathic scoliosis (AIS) patients. The purpose of this study was to explore whether the Roussouly classification could be used to help surgeons restore the ideal sagittal alignment for AIS patients to avoid the development of proximal junctional kyphosis (PJK). METHODS: In this retrospective cohort study, eighty-seven patients with Lenke 5 AIS who underwent surgery from January 2010 to August 2020 were enrolled and divided into two groups: the PJK group and the non-PJK group. All patients were classified into "current types" and "ideal types" according to two versions of the Roussouly classification, and the mismatch rate was evaluated in terms of the consistency between their current type and ideal type. Student's t test, Mann‒Whitney U test, Pearson's Chi-square test, and others were used to compare the two groups regarding patient demographic characteristics (age, sex, Risser sign, etc.) and radiographic parameters (sagittal vertical axis [SVA]; thoracic kyphosis [TK]; thoracolumbar junctional kyphosis [TLK]; lumbar lordosis [LL]; pelvic incidence [PI]; pelvic tilt [PT]; sacral slope [SS]; upper instrumented vertebra [UIV]; lower instrumented vertebra [LIV]; etc.). Multivariate logistic regression with backwards stepwise selection was performed to identify the risk factors for PJK. RESULTS: PJK was observed in 16 out of 87 patients (18.4%) until the final follow-up. The incidence of PJK was significantly higher in the patients not matching their ideal type than in those who did after surgery (60.9% vs. 3.1%, p = 0.000). The patients with ideal Type 1 had the highest incidence of PJK, while the lowest incidence was observed in patients with ideal Type 2 (50.0% vs. 5.1%, p = 0.000). The PJK group had greater TK, LL, and PI-LL than the non-PJK group before and after surgery. The postoperative PJA in the PJK group was also larger than that in the non-PJK group. Multivariate logistic regression revealed that postoperative Roussouly type mismatch was significantly associated with the occurrence of PJK (OR = 64.2, CI = 9.6-407.1, p = 0.000). CONCLUSIONS: The Roussouly classification could serve as a prognostic tool for PJK in Lenke 5 AIS patients. Corrective surgery should restore sagittal alignment with respect to the patient's ideal sagittal profile (according to the Roussouly classification based on the PI) to decrease the incidence of PJK in AIS patients.


Assuntos
Cifose , Anormalidades Musculoesqueléticas , Escoliose , Adulto , Animais , Humanos , Adolescente , Escoliose/diagnóstico por imagem , Escoliose/cirurgia , Estudos Retrospectivos , Cifose/diagnóstico por imagem , Cifose/cirurgia , Ácido Dioctil Sulfossuccínico , Sacro
16.
Ecotoxicol Environ Saf ; 270: 115853, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38128313

RESUMO

BACKGROUND: Manganese (Mn) and iron (Fe) are essential trace elements for humans, yet excessive exposure to Mn or Fe can accumulate in the central nervous system (CNS) and cause neurotoxicity. The purpose of this study was to investigate the effects of Mn and Fe exposure, alone or in combination, on inducing oxidative stress-induced neurological damage in rat cortical and SH-SY5Y cells, and to determine whether combined exposure to these metals increases their individual toxicity. METHODS: SH-SY5Y cells and male Sprague-Dawley rats were used to observe the effects of oxidative stress-induced neurological damage induced by exposure to manganese and iron alone or in combination. To detect the expression of anti-oxidative stress-related proteins, Nrf2, HO-1, and NQO1, and the apoptosis-related proteins, Bcl2 and Bax, and the neurological damage-related protein, α-syn. To detect reactive oxygen species generation and apoptosis. To detect the expression of the rat cortical protein Nrf2. To detect the production of proinflammatory cytokines. RESULTS: We demonstrate that juvenile developmental exposure to Mn and Fe and their combination impairs cognitive performance in rats by inducing oxidative stress causing neurodegeneration in the cortex. Mn, Fe, and their combined exposure increased the expression of ROS, Bcl2, Bax, and α-syn, activated the inflammatory factors IL-6 and IL-12, inhibited the activities of SOD and GSH, and induced oxidative stress-induced neurodegeneration both in rats and SH-SY5Y cells. Combined Mn-Fe exposure attenuated the oxidative stress induced by Mn and Fe exposure alone by increasing the expression of antioxidant factors Nrf2, HO-1, and NQO1. CONCLUSION: In both in vivo and in vitro studies, manganese and iron alone or in combination induced oxidative stress, leading to neuronal damage. In contrast, combined exposure to manganese and iron mitigated the oxidative stress induced by exposure to manganese and iron alone by increasing the expression of antioxidant factors. Therefore, studies to elucidate the main causes of toxicity and establish the molecular mechanisms of toxicity should help to develop more effective therapeutic modalities in the future.


Assuntos
Manganês , Neuroblastoma , Humanos , Masculino , Ratos , Animais , Manganês/toxicidade , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Ferro/metabolismo , Proteína X Associada a bcl-2/metabolismo , Ratos Sprague-Dawley , Estresse Oxidativo , Apoptose , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , NAD(P)H Desidrogenase (Quinona)/farmacologia
17.
Ecotoxicol Environ Saf ; 270: 115873, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38150749

RESUMO

Heavy metal(loid)s contamination prevails in the water-soil-plant system around non-ferrous metal mining areas. The present study aimed to evaluate the heavy metal(loid)s contamination in Nandan Pb-Zn mining area (Guangxi, China). A total of 36 river water samples, 75 paired paddy soil and rice samples, and 128 paired upland soil and plant samples were collected from this area. The concentrations of arsenic (As), lead (Pb), and cadmium (Cd) in these samples were measured. Results showed that the average water quality indexes (WQIs) at the 12 sampling sites along the main river ranged from 41 to 5008, indicating the water qualities decreasing from "Excellent" to "Undrinkable". The WQIs nearby tailings or industrial park were significantly higher than those at the other sites. 34.0% and 64.5% of soil samples exceeded the risk screening values for As and Cd. The Pb and Cd concentrations in all rice samples exceeded the Chinese food safety limits by 18.7% and 82.7%, respectively. Leafy vegetables had a higher concentration of As, Pb, and Cd than other vegetables, exceeding the maximum permissible limits by 14.1%, 61.2%, and 40.0%, respectively. The biological accumulation coefficient (BAC) of Cd was the highest in rice and lettuce leaves. The hazard quotients (HQs) of As and Cd, indicating non-carcinogenic risks, were 4.15 and 1.76 in adult males, and 3.40 and 1.45 in adult females, all higher than the permitted level (1.0). The carcinogenic probabilities of As and Cd from rice and leafy vegetables consumption were all higher than 1 × 10-4. We conclude that metal(loid)s contamination of the water-soil-plant system has posed great non-carcinogenic and carcinogenic risks to the local population.


Assuntos
Arsênio , Metais Pesados , Poluentes do Solo , Humanos , Adulto , Cádmio/análise , Arsênio/análise , Chumbo , Solo , Poluentes do Solo/análise , China , Metais Pesados/análise , Verduras , Mineração , Medição de Risco , Monitoramento Ambiental
18.
Pestic Biochem Physiol ; 202: 105915, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38879296

RESUMO

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is activated by infections of bacteria, fungi, viruses and parasites and mediated cellular and humoral immune responses. In the pea aphid Acyrthosiphon pisum little is known about the function of JAK/STAT signaling in its immune system. In this study, we first showed that expression of genes in the JAK/STAT signaling, including the receptors Domeless1/2, Janus kinase (JAK) and transcriptional factor Stat92E, is up-regulated upon bacteria Escherichia coli and Staphylococcus aureus and fungus Beauveria bassiana infections. After knockdown of expression of these genes by means of dsRNA injection, the aphids harbored more bacteria and suffered more death after infected with E. coli and S. aureus, but showed no significant change after B. bassiana infection. Our study suggests the JAK/STAT signaling contributes to the defense against bacterial infection in the pea aphid.


Assuntos
Afídeos , Janus Quinases , Fatores de Transcrição STAT , Transdução de Sinais , Animais , Janus Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Staphylococcus aureus/fisiologia , Escherichia coli , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Beauveria/fisiologia
19.
Toxicol Ind Health ; 40(1-2): 41-51, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37984499

RESUMO

Lead is one of the heavy metals that is toxic and widely distributed in the environment, and children are more sensitive to the toxic effects of lead because the blood-brain barrier and immune system are not yet well developed. The objective of the study was to investigate the clinical characteristics of lead poisoning in children aged 0∼6 years in a hospital in Guangxi, and to provide scientific basis for the prevention and treatment of lead poisoning. We collected and analyzed the clinical data of 32 children with lead poisoning admitted to a hospital in Guangxi from 2010 to 2018. The results showed that most of the 32 cases presented with hyperactivity, irritability, poor appetite, abdominal pain, diarrhea, or constipation. The hemoglobin (HGB), mean corpusular volume (MCV), mean corpuscular hemoglobin (MCH), and hematocrit (HCT) of the lead-poisoned children were all decreased to different degrees and were below normal acceptable levels. Urinary ß2-microglobulin was increased. Blood lead levels (BLL) decreased significantly after intravenous injection of the lead chelator, calcium disodium edetate (CaNa2-EDTA). In addition, HGB returned to normal levels, while MCV, MCH, and HCT increased but remained below normal levels. Urinary ß2-microglobulin was reduced to normal levels. Therefore, in this cohort of children, the high-risk factors for lead poisoning are mainly Chinese medicines, such as baby powder. In conclusion, lead poisoning caused neurological damage and behavioral changes in children and decreased erythrocyte parameters, leading to digestive symptoms and renal impairment, which can be attenuated by CaNa2-EDTA treatment.


Assuntos
Intoxicação por Chumbo , Chumbo , Criança , Lactente , Humanos , Chumbo/toxicidade , China/epidemiologia , Ácido Edético , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/etiologia , Hematócrito , Hemoglobinas
20.
Angew Chem Int Ed Engl ; 63(12): e202315222, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38299697

RESUMO

A new electrochemical transformation is presented that enables chemists to couple simple alkyl carboxylic acid derivatives with an electrophilic amine reagent to construct C(sp3 )-N bond. The success of this reaction hinges on the merging of cooperative electrochemical reduction with nickel catalysis. The chemistry exhibits a high degree of practicality, showcasing its wide applicability with 1°, 2°, 3° carboxylic acids and remarkable compatibility with diverse functional groups, even in the realm of late-stage functionalization. Furthermore, extensive mechanistic studies have unveiled the engagement of alkyl radicals and iminyl radicals; and elucidated the multifaceted roles played by i Pr2 O, Ni catalyst, and electricity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA