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1.
Artigo em Inglês | MEDLINE | ID: mdl-38243974

RESUMO

OBJECTIVE: To investigate the effect of high blood glucose on the decline in the estimated glomerular filtration rate (eGFR) in the elderly. METHODS: We compared the decline in eGFR of diabetic and non-diabetic groups in the noninterventional state and analyzed the effect of hyperglycemia on the decline in eGFR among the elderly in a retrospective analysis of 1,223 cases of elderly people aged 65 years or older with a 4-year follow-up period. RESULTS: The prevalence of diabetes in the elderly increased significantly from 12.67% in 2017 to 16.68% in 2021. The rate of decline in eGFR in patients with diabetes was higher than in the population without diabetes, at 9.29% and 5.32%, respectively (both p <0.05). CONCLUSION: The results of this study revealed that the prevalence of diabetes in the elderly increased significantly, and there is a more rapid decrease in the eGFR levels in those with diabetes than those without diabetes.

2.
NPJ Precis Oncol ; 8(1): 19, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38273014

RESUMO

Recent advances in the genomics of glioblastoma (GBM) led to the introduction of molecular neuropathology but failed to translate into treatment improvement. This is largely attributed to the genetic and phenotypic heterogeneity of GBM, which are considered the major obstacle to GBM therapy. Here, we use advanced human GBM-like organoid (LEGO: Laboratory Engineered Glioblastoma-like Organoid) models and provide an unprecedented comprehensive characterization of LEGO models using single-cell transcriptome, DNA methylome, metabolome, lipidome, proteome, and phospho-proteome analysis. We discovered that genetic heterogeneity dictates functional heterogeneity across molecular layers and demonstrates that NF1 mutation drives mesenchymal signature. Most importantly, we found that glycerol lipid reprogramming is a hallmark of GBM, and several targets and drugs were discovered along this line. We also provide a genotype-based drug reference map using LEGO-based drug screen. This study provides new human GBM models and a research path toward effective GBM therapy.

3.
Bio Protoc ; 13(9): e4665, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37323628

RESUMO

Accidental wounding of the peripheral nervous system leads to acute neural dysfunction. Normally, chronic deficits are overcome because peripheral nerves naturally regenerate. However, various genetic and metabolic defects can impair their natural regenerative capacity, which may be due to neuron-extrinsic mechanisms. Therefore, characterizing the behavior of multiple cells during nerve injury and repair in vivo is a pressing need in regenerative medicine. Here, we detail a method for precise wounding of sensory axons in zebrafish, followed by high-resolution in toto long-term quantitative videomicroscopy of neurons, Schwann cells, and macrophages. This protocol can be easily adapted to study the effects of targeted genetic or metabolic disruptions in zebrafish and other suitable organisms, as well as for screening pharmacological agents with therapeutic potential. Graphical overview.

4.
Int J Mol Sci ; 23(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35563169

RESUMO

In this study, we performed an association analysis of metabolomics and transcriptomics to reveal the anthocyanin biosynthesis mechanism in a new purple-leaf tea cultivar Zikui (Camellia sinensis cv. Zikui) (ZK). Three glycosylated anthocyanins were identified, including petunidin 3-O-glucoside, cyanidin 3-O-galactoside, and cyanidin 3-O-glucoside, and their contents were the highest in ZK leaves at 15 days. This is the first report on petunidin 3-O-glucoside in purple-leaf tea. Integrated analysis of the transcriptome and metabolome identified eleven dependent transcription factors, among which CsMYB90 had strong correlations with petunidin 3-O-glucoside, cyanidin 3-O-galactoside, and cyanidin 3-O-glucoside (PCC > 0.8). Furthermore, we also identified key correlated structural genes, including two positively correlated F3'H (flavonoid-3'-hydroxylase) genes, two positively correlated ANS (anthocyanin synthase) genes, and three negatively correlated PPO (polyphenol oxidase) genes. Overexpression of CsMYB90 in tobacco resulted in dark-purple transgenic calluses. These results showed that the increased accumulation of three anthocyanins in ZK may promote purple-leaf coloration because of changes in the expression levels of genes, including CsMYB90, F3'Hs, ANSs, and PPOs. These findings reveal new insight into the molecular mechanism of anthocyanin biosynthesis in purple-leaf tea plants and provide a series of candidate genes for the breeding of anthocyanin-rich cultivars.


Assuntos
Camellia sinensis , Antocianinas/metabolismo , Camellia sinensis/genética , Camellia sinensis/metabolismo , Galactosídeos/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosídeos/metabolismo , Metabolômica , Melhoramento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Chá/metabolismo , Transcriptoma
5.
Front Vet Sci ; 9: 994652, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36590810

RESUMO

Objective: The aim of the study was to establish and study an intrahepatic portal vein infection hepatic alveolar echinococcosis (HAE) C57 mouse model and provide a theoretical basis for clinical research on HAE. Methods: C57 mice were used to establish the HAE mouse model. The location, size, morphology, appearance, and pathological changes in liver lesions in different groups of mice were characterized using ultrasound, magnetic resonance imaging (MRI), and haematoxylin and eosin staining. Results: The mortality rate of the C57 mice was 20%, and the success rate of infection was 75%. The abdominal ultrasound images and MRIs clearly indicated the location, size, shape, and appearance of the liver lesions and the relationship between the lesions and the adjacent organs. The size, morphology, and signal of the livers in the control group were normal. The pathological results of the experimental group indicated a hepatic vesicular acinar cyst, while those of the control group exhibited normal livers. Conclusion: The intrahepatic portal vein infection HAE mouse model was successfully established.

6.
Sci Adv ; 7(20)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33980478

RESUMO

Despite its importance in regulating cellular or tissue function, electrical conductivity can only be visualized in tissue indirectly as voltage potentials using fluorescent techniques, or directly with radio waves. These either requires invasive procedures like genetic modification or suffers from limited resolution. Here, we introduce radio-frequency thermoacoustic mesoscopy (RThAM) for the noninvasive imaging of conductivity by exploiting the direct absorption of near-field ultrashort radio-frequency pulses to stimulate the emission of broadband ultrasound waves. Detection of ultrasound rather than radio waves enables micrometer-scale resolutions, over several millimeters of tissue depth. We confirm an imaging resolution of <30 µm in phantoms and demonstrate microscopic imaging of conductivity correlating to physical structures in 1- and 512-cell zebrafish embryos, as well as larvae. These results support RThAM as a promising method for high-resolution, label-free assessment of conductivity in tissues.

7.
MicroPubl Biol ; 20212021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33688624

RESUMO

Sarm1 is an evolutionary conserved protein that is essential for Wallerian axon degeneration. Sarm1 has emerged as a therapeutic target to treat neuropathies derived from metabolic or chemical stress and physical injury of axons. Yet, the full repertoire of consequences of inhibiting Sarm1 remains unknown. Here we show that loss of Sarm1 in zebrafish does not affect the sensorimotor transformations that underlie rheotaxis. In addition, Sarm1 deficit accelerates the re-growth of regenerating axons. These data indicate that systemic inhibition of Sarm1 is a viable therapeutic option compatible with sustained nervous system function.

9.
Commun Biol ; 3(1): 49, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-32001778

RESUMO

Protecting the nervous system from chronic effects of physical and chemical stress is a pressing clinical challenge. The obligate pro-degenerative protein Sarm1 is essential for Wallerian axon degeneration. Thus, blocking Sarm1 function is emerging as a promising neuroprotective strategy with therapeutic relevance. Yet, the conditions that will most benefit from inhibiting Sarm1 remain undefined. Here we combine genome engineering, pharmacology and high-resolution intravital videmicroscopy in zebrafish to show that genetic elimination of Sarm1 increases Schwann-cell resistance to toxicity by diverse chemotherapeutic agents after axonal injury. Synthetic degradation of Sarm1-deficient axons reversed this effect, suggesting that glioprotection is a non-autonomous effect of delayed axon degeneration. Moreover, loss of Sarm1 does not affect macrophage recruitment to nerve-wound microenvironment, injury resolution, or neural-circuit repair. These findings anticipate that interventions aimed at inhibiting Sarm1 can counter heightened glial vulnerability to chemical stressors and may be an effective strategy to reduce chronic consequences of neurotrauma.


Assuntos
Antineoplásicos/efeitos adversos , Proteínas do Domínio Armadillo/deficiência , Axônios/metabolismo , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Degeneração Walleriana/genética , Animais , Animais Geneticamente Modificados , Proteínas do Domínio Armadillo/genética , Axônios/patologia , Imunofluorescência , Loci Gênicos , Mutagênese , Fenótipo , Peixe-Zebra
10.
Int J Mol Sci ; 17(4): 515, 2016 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-27058536

RESUMO

Cisatracurium besylate is an ideal non-depolarizing muscle relaxant which is widely used in clinical application. However, some studies have suggested that cisatracurium besylate can affect cell proliferation. Moreover, its specific mechanism of action remains unclear. Here, we found that the number of GFP-LC3 (green fluoresent protein-light chain 3) positive autophagosomes and the rate of mitochondria fracture both increased significantly in drug-treated GFP-LC3 and MitoDsRed stable HeLa cells. Moreover, cisatracurium promoted the co-localization of LC3 and mitochondria and induced formation of autolysosomes. Levels of mitochondrial proteins decreased, which were reversed by the lysosome inhibitor Bafinomycin A1. Similar results with evidence of dose-dependent effects were found in both HeLa and Human Umbilical Vein Endothelial Cells (HUVECs). Cisatracurium lowered HUVEC viability to 0.16 (OD490) at 100 µM and to 0.05 (OD490) after 48 h in vitro; it increased the cell death rate to 56% at 100 µM and to 60% after 24 h in a concentration- and time-dependent manner (p < 0.01). Cell proliferation decreased significantly by four fold in Atg5 WT (wildtype) MEF (mouse embryonic fibroblast) (p < 0.01) but was unaffected in Atg5 KO (Knockout) MEF, even upon treatment with a high dose of cisatracurium. Cisatracurium induced significant increase in cell death of wild-type MEFs even in the presence of the apoptosis inhibitor zVAD. Thus, we conclude that activation of both the autophagic cell death and cell apoptosis pathways contributes to cisatracurium-mediated cell injury.


Assuntos
Apoptose/efeitos dos fármacos , Atracúrio/análogos & derivados , Autofagia/efeitos dos fármacos , Bloqueadores Neuromusculares/efeitos adversos , Animais , Atracúrio/efeitos adversos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteólise/efeitos dos fármacos
11.
Curr Biol ; 25(22): R1068-9, 2015 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-26583893

RESUMO

Environmental insult, disease or trauma can affect the physical integrity of neuronal circuits, and the inability of many neurons to regenerate injured axons invariably leads to irreversible neural dysfunction. The conserved second messenger cyclic adenosine monophosphate (cAMP) can promote axonal re-growth. Widely used pharmacological or genetic approaches to increase intracellular levels of cAMP are often inadequate for precise neural-circuit reconstruction because their activity cannot be easily timed to specific target cells. These shortcomings have prevented the controlled repair of pre-defined neurons at selected time points in whole specimens. Thus, technologies to guide neuronal repair in time and space would enable studies of neural-circuit recovery with unprecedented resolution. Towards this aim, we have implemented a proof-of-principle optogenetic method to promote the selective regeneration of refractory axons in a living vertebrate.


Assuntos
Regeneração Nervosa/fisiologia , Neurônios/fisiologia , Optogenética/métodos , Animais , Axônios/fisiologia , Humanos
12.
FEBS Lett ; 589(15): 1847-54, 2015 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-25980607

RESUMO

UNC-51 like kinase (ULK1) translocates to dysfunctional mitochondria and is involved in mitophagy, but the mechanisms responsible for ULK1 activation and translocation remain unclear. Here, we found that hypoxia induces phosphorylation of ULK1 at Serine-555 by Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Unlike wild-type ULK1, an ULK1 (S555A) mutant cannot translocate to mitochondria in response to hypoxia. Inhibition or knockdown of AMPK prevents ULK1 translocation and inhibits mitophagy. Finally, the phospho-mimic ULK1 (S555D) mutant, but not ULK1 (S555A), rescues mitophagy in AMPK-knockdown cells. Thus, we conclude that AMPK-dependent phosphorylation of ULK1 is critical for translocation of ULK1 to mitochondria and for mitophagy in response to hypoxic stress.


Assuntos
Adenilato Quinase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitocôndrias/metabolismo , Mitofagia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia , Células Cultivadas , Células HeLa , Humanos , Camundongos , Microscopia de Fluorescência , Mitocôndrias/enzimologia , Fosforilação , Transporte Proteico
13.
Environ Pollut ; 190: 133-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24747345

RESUMO

Occupational and experimental studies have revealed the organs most affected by dimethylformamide (DMF) are liver and gastrointestinal tract. However, few studies have focused on the potential effect of outdoor pollution of DMF. This study examined the health risk of hospitalization due to digestive system disease by time series studies in a case city Longwan, China. The urine metabolite of DMF was correlated well with DMF exposure concentration (EC). A 101.0-µg/m(3) (interquartile range) increase in the two-day moving average of DMF EC was associated with a 1.10 (1.01 Ëœ 1.20), 1.22 (1.10 Ëœ 1.35), and 1.05 (0.90 Ëœ 1.22) increase in hospitalization for total digestive system diseases, liver disease, and gastrointestinal tract disease, respectively. The exposure-dose response between DMF and the relative risk of liver disease was linear only below 350 µg/m(3). These findings highlight a previously unrecognized health problem related to VOCs released into the outdoor environment.


Assuntos
Poluentes Atmosféricos/toxicidade , Doenças do Sistema Digestório/epidemiologia , Dimetilformamida/toxicidade , Exposição Ambiental/análise , Poluentes Atmosféricos/metabolismo , Poluição do Ar/estatística & dados numéricos , China , Doenças do Sistema Digestório/induzido quimicamente , Doenças do Sistema Digestório/metabolismo , Dimetilformamida/metabolismo , Exposição Ambiental/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Humanos , Fígado/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/toxicidade
14.
EMBO Rep ; 15(5): 566-75, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24671035

RESUMO

Autophagy eliminates dysfunctional mitochondria in an intricate process known as mitophagy. ULK1 is critical for the induction of autophagy, but its substrate(s) and mechanism of action in mitophagy remain unclear. Here, we show that ULK1 is upregulated and translocates to fragmented mitochondria upon mitophagy induction by either hypoxia or mitochondrial uncouplers. At mitochondria, ULK1 interacts with FUNDC1, phosphorylating it at serine 17, which enhances FUNDC1 binding to LC3. A ULK1-binding-deficient mutant of FUNDC1 prevents ULK1 translocation to mitochondria and inhibits mitophagy. Finally, kinase-active ULK1 and a phospho-mimicking mutant of FUNDC1 rescue mitophagy in ULK1-null cells. Thus, we conclude that FUNDC1 regulates ULK1 recruitment to damaged mitochondria, where FUNDC1 phosphorylation by ULK1 is crucial for mitophagy.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , Mitofagia/fisiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Homóloga à Proteína-1 Relacionada à Autofagia , Hipóxia Celular , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/fisiologia , Proteínas Mitocondriais/genética , Mutação , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/biossíntese , Regulação para Cima
15.
J Biol Chem ; 289(15): 10691-10701, 2014 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-24573672

RESUMO

Mitophagy receptors mediate the selective recognition and targeting of damaged mitochondria by autophagosomes. The mechanism for the regulation of these receptors remains unknown. Here, we demonstrated that a novel hypoxia-responsive microRNA, microRNA-137 (miR-137), markedly inhibits mitochondrial degradation by autophagy without affecting global autophagy. miR-137 targets the expression of two mitophagy receptors NIX and FUNDC1. Impaired mitophagy in response to hypoxia caused by miR-137 is reversed by re-expression of FUNDC1 and NIX expression vectors lacking the miR-137 recognition sites at their 3' UTR. Conversely, miR-137 also suppresses the mitophagy induced by fundc1 (CDS+3'UTR) but not fundc1 (CDS) overexpression. Finally, we found that miR-137 inhibits mitophagy by reducing the expression of the mitophagy receptor thereby leads to inadequate interaction between mitophagy receptor and LC3. Our results demonstrated the regulatory role of miRNA to mitophagy receptors and revealed a novel link between miR-137 and mitophagy.


Assuntos
Autofagia , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Proteínas Mitocondriais/metabolismo , Regiões 3' não Traduzidas , Animais , Hipóxia Celular , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Vetores Genéticos , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Fagossomos/metabolismo
16.
Environ Sci Pollut Res Int ; 21(5): 3534-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24271731

RESUMO

Dimethylformamide (DMF) is a broad solvent used in the production of synthetic leather. Decades of year's research have been focused on workers in leather factories suffering from the release of DMF. However, little attention was paid on general population. Here, we examined the relationship between consistent DMF exposure and annual hospitalizations of local residents in Longwan, China, in 2008. We found a positive correlation with a relative risk (RR) increase of 1.110 for total hospitalizations. When the data were stratified by sex, we observed a higher correlation for female hospitalizations than for male hospitalizations, with RR values of 1.55 and 1.084, respectively. This might be attributed to the differences in genotypes of oxidant enzyme between gender. The significance of the correlations did not disappear after we excluded the extreme value of DMF or adjusted for SO2, NO2, and PM10. Population living near the leather factory has experienced almost constant DMF exposure, and real concern should be raised regarding such exposure. Governments should take responsibility for the protection of not only occupational workers but also residents, especially women.


Assuntos
Poluentes Atmosféricos/toxicidade , Dimetilformamida/toxicidade , Exposição Ambiental/efeitos adversos , Solventes/toxicidade , Têxteis , China/epidemiologia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Risco , Medição de Risco
17.
Sci Total Environ ; 450-451: 250-8, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23500823

RESUMO

Estimations of air pollutant emissions from vehicles in China under different energy and emission abatement policy scenarios are presented in this paper. Three scenarios are designed: (i) "business as usual" (BAU); (ii) "advanced fuel economy" (AFE); and (iii) "alternative energy replacement" (AER). The CO, VOCs, NOx, PM10, and CO2 emissions are predicted to reach 105.8, 5.9, 7.5, 1.1, and 3522.6 million tons, respectively, in the BAU scenario by 2030. In the AFE scenario, the CO, VOCs, NOx, PM10, and CO2 emissions in 2030 will be abated by 23.8%, 18.6%, 25.3%, 18.2%, and 24.5% respectively compared with the BAU scenario. In the AER scenario, the CO and VOCs in 2030 will be further reduced by 15.9% and 6.1% respectively, while NOx, PM10, and CO2 will be increased by 10.7%, 33.3%, and 2.0% compared with AFE. In conclusion, our models indicate that the emission abatement policies introduced by governmental institutions are potentially viable, as long as they are effectively implemented.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Gasolina , Modelos Teóricos , Veículos Automotores , Emissões de Veículos/análise , China , Veículos Automotores/normas
18.
Cancer Res ; 73(8): 2682-94, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23418321

RESUMO

Cancer stem cells are implicated in tumor progression, metastasis, and recurrence, although the exact mechanisms remain poorly understood. Here, we show that the expression of cellular prion protein (PrPc, PRNP) is positively correlated with an increased risk of metastasis in colorectal cancer. PrPc defines a subpopulation of CD44-positive cancer stem cells that contributes to metastatic capacity. PrPc(+)CD44(+) colorectal cancer stem cells displayed high liver metastatic capability, unlike PrPc(-)CD44(+) stem cells, that was inhibited by RNAi-mediated attenuation of PrPc. Notably, administration of PrPc monoclonal antibodies significantly inhibited tumorigenicity and metastasis of colorectal cancer stem cells in mouse models of orthotopic metastasis. PrPc promoted epithelial to mesenchymal transition (EMT) via the ERK2 (MAPK1) pathway, thereby conferring high metastatic capacity. Our findings reveal the function of PrPc in regulating EMT in cancer stem cells, and they identify PrPc as candidate therapeutic target in metastatic colorectal cancer.


Assuntos
Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Receptores de Hialuronatos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas PrPC/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Transição Epitelial-Mesenquimal/genética , Feminino , Expressão Gênica , Humanos , Receptores de Hialuronatos/genética , Camundongos , Camundongos Nus , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Gradação de Tumores , Metástase Neoplásica , Proteínas PrPC/genética , Proteínas PrPC/imunologia , Transplante Heterólogo
19.
J Biol Chem ; 287(2): 1054-65, 2012 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-22065578

RESUMO

Overwhelming evidence indicates that Bax and Bak are indispensable for mediating cytochrome c release from mitochondria during apoptosis. Here we report a Bax/Bak-independent mechanism of cytochrome c release and apoptosis. We identified a natural diterpenoid compound that induced apoptosis in bax/bak double knock-out murine embryonic fibroblasts and substantially reduced the tumor growth from these cells implanted in mice. Treatment with the compound significantly increased expression of Bim, which migrated to mitochondria, altering the conformation of and forming oligomers with resident Bcl-2 to induce cytochrome c release and caspase activation. Importantly, purified Bim and Bcl-2 proteins cooperated to permeabilize a model mitochondrial outer membrane; this was accompanied by oligomerization of these proteins and deep embedding of Bcl-2 in the membrane. Therefore, the diterpenoid compound induces a structural and functional conversion of Bcl-2 through Bim to permeabilize the mitochondrial outer membrane, thereby inducing apoptosis independently of Bax and Bak. Because Bcl-2 family proteins play important roles in cancer development and relapse, this novel cell death mechanism can be explored for developing more effective anticancer therapeutics.


Assuntos
Proteínas Reguladoras de Apoptose/biossíntese , Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas/biossíntese , Proteína X Associada a bcl-2/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular Transformada , Citocromos c/genética , Citocromos c/metabolismo , Regulação da Expressão Gênica/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Membranas Mitocondriais/metabolismo , Permeabilidade/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína X Associada a bcl-2/genética
20.
J Biol Chem ; 286(13): 11649-58, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21292769

RESUMO

Mutations in Parkin, an E3 ubiquitin ligase that regulates protein turnover, represent one of the major causes of familial Parkinson disease, a neurodegenerative disorder characterized by the loss of dopaminergic neurons and impaired mitochondrial functions. The underlying mechanism by which pathogenic Parkin mutations induce mitochondrial abnormality is not fully understood. Here, we demonstrate that Parkin interacts with and subsequently ubiquitinates dynamin-related protein 1 (Drp1), for promoting its proteasome-dependent degradation. Pathogenic mutation or knockdown of Parkin inhibits the ubiquitination and degradation of Drp1, leading to an increased level of Drp1 for mitochondrial fragmentation. These results identify Drp1 as a novel substrate of Parkin and suggest a potential mechanism linking abnormal Parkin expression to mitochondrial dysfunction in the pathogenesis of Parkinson disease.


Assuntos
GTP Fosfo-Hidrolases/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Doença de Parkinson/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/biossíntese , Ubiquitinação , Dinaminas , GTP Fosfo-Hidrolases/genética , Regulação Enzimológica da Expressão Gênica/genética , Células HeLa , Humanos , Proteínas Associadas aos Microtúbulos/genética , Mitocôndrias/genética , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Mutação , Doença de Parkinson/genética , Doença de Parkinson/patologia , Complexo de Endopeptidases do Proteassoma/genética , Ubiquitina-Proteína Ligases/genética
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