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1.
Sci Rep ; 14(1): 14788, 2024 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926484

RESUMO

This study aims to assess the association between nicotine replacement therapy (NRT), varenicline, and untreated smoking with the risk of developing eye disorders. We employed a new-user design to investigate the association between NRT use and the incidence of eye disorders by the Taiwan National Health Insurance program. This study included 8416 smokers who received NRT and 8416 smokers who did not receive NRT (control group) matched using propensity scores between 2007 and 2018. After adjustment for relevant factors, a multivariable Cox regression analysis revealed that compared with untreated smokers, NRT use was associated with a significantly reduced risk of macular degeneration (hazard ratio [HR]: 0.34; 95% confidence interval [CI]: 0.13-0.87, P = 0.024). When stratified by dose, short-term NRT use (8-28 defined daily doses) was associated with significantly lower risk of glaucoma (HR: 0.35; 95% CI: 0.16-0.80, P = 0.012) and a trend toward reduced risk of cataract (HR: 0.60; 95% CI: 0.36-1.01, P = 0.053) compared to no treatment. However, these associations were not observed with long-term NRT use. The results of this real-world observational study indicate that NRT use, particularly short-term use, was associated with a lower risk of certain eye disorders compared to no treatment for smoking cessation. Long-term NRT use did not demonstrate the same benefits. Thus, short-term NRT may be a beneficial treatment strategy for reducing the risk of eye disorders in smokers attempting to quit. However, further evidence is required to verify these findings and determine the optimal duration of NRT use.


Assuntos
Catarata , Glaucoma , Degeneração Macular , Abandono do Hábito de Fumar , Humanos , Masculino , Feminino , Glaucoma/epidemiologia , Glaucoma/etiologia , Pessoa de Meia-Idade , Degeneração Macular/epidemiologia , Degeneração Macular/etiologia , Estudos Retrospectivos , Catarata/epidemiologia , Taiwan/epidemiologia , Idoso , Adulto , Fumar/efeitos adversos , Fumar/epidemiologia , Dispositivos para o Abandono do Uso de Tabaco , Incidência , Vareniclina/uso terapêutico
2.
Cell Commun Signal ; 21(1): 156, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37370099

RESUMO

BACKGROUND: Golgi apparatus (GA) is assembled as a crescent-like ribbon in mammalian cells under immunofluorescence microscope without knowing the shaping mechanisms. It is estimated that roughly 1/5 of the genes encoding kinases or phosphatases in human genome participate in the assembly of Golgi ribbon, reflecting protein modifications play major roles in building Golgi ribbon. METHODS: To explore how Golgi ribbon is shaped as a crescent-like structure under the guidance of protein modifications, we identified a protein complex containing the scaffold proteins Ajuba, two known GA regulators including the protein kinase Aurora-A and the protein arginine methyltransferase PRMT5, and the common substrate of Aurora-A and PRMT5, HURP. Mutual modifications and activation of PRMT5 and Aurora-A in the complex leads to methylation and in turn phosphorylation of HURP, thereby producing HURP p725. The HURP p725 localizes to GA vicinity and its distribution pattern looks like GA morphology. Correlation study of the HURP p725 statuses and GA structure, site-directed mutagenesis and knockdown-rescue experiments were employed to identify the modified HURP as a key regulator assembling GA as a crescent ribbon. RESULTS: The cells containing no or extended distribution of HURP p725 have dispersed GA membranes or longer GA. Knockdown of HURP fragmentized GA and HURP wild type could, while its phosphorylation deficiency mutant 725A could not, restore crescent Golgi ribbon in HURP depleted cells, collectively indicating a crescent GA-constructing activity of HURP p725. HURP p725 is transported, by GA membrane-associated ARF1, Dynein and its cargo adaptor Golgin-160, to cell center where HURP p725 forms crescent fibers, binds and stabilizes Golgi assembly factors (GAFs) including TRIP11, GRASP65 and GM130, thereby dictating the formation of crescent Golgi ribbon at nuclear periphery. CONCLUSIONS: The Ajuba/PRMT5/Aurora-A complex integrates the signals of protein methylation and phosphorylation to HURP, and the HURP p725 organizes GA by stabilizing and recruiting GAFs to its crescent-like structure, therefore shaping GA as a crescent ribbon. Therefore, the HURP p725 fiber serves a template to construct GA according to its shape. Video Abstract.


Assuntos
Núcleo Celular , Complexo de Golgi , Animais , Humanos , Complexo de Golgi/metabolismo , Fosforilação , Núcleo Celular/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Mamíferos/metabolismo
3.
ACS Med Chem Lett ; 13(9): 1510-1516, 2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36105331

RESUMO

Autophagy plays essential roles in a wide variety of physiological processes, such as cellular homeostasis, metabolism, development, differentiation, and immunity. Selective pharmacological modulation of autophagy is considered a valuable potential therapeutic approach to treat diverse human diseases. However, development of such therapies has been greatly impeded by the lack of specific small molecule autophagy modulators. Here, we performed structure-activity relationship studies on a previously discovered weak Bcl-2 inhibitor SW076956, and developed a panel of small molecule compounds that selectively released Bcl-2-mediated inhibition of autophagy-related Beclin 1 compared to apoptosis-related Bax at nanomolar concentration. Our NMR analysis showed that compound 35 directly binds Bcl-2 and specifically inhibits the interaction between the Bcl-2 and Beclin 1 BH3 domains without disruption of the Bcl-2-Bax BH3 interaction. More broadly, this proof-of-concept study demonstrates that targeting protein-protein interactions of the intrinsic autophagy regulatory network can serve as a valuable strategy for the development of autophagy-based therapeutics.

4.
J Pers Med ; 12(2)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35207619

RESUMO

BACKGROUND: This study aimed to evaluate the cost-effectiveness of treating transplant-ineligible myeloma patients with either a bortezomib plus thalidomide plus dexamethasone (VTD) or a bortezomib plus melphalan plus prednisolone (VMP) treatment in Taiwan. METHODS: Newly diagnosed, transplant-ineligible myeloma patients with VTD or VMP therapy were enrolled from two medical centers in southern Taiwan. Quality-adjusted life years (QALYs) were used as the measurement unit of the effectiveness evaluation, and the incremental cost-effectiveness ratio (ICER) was used for comparison between the two groups. A net monetary benefit approach and cost-effectiveness acceptability curve were also used for the cost-effectiveness assessment. A one-way sensitivity analysis was used to check the impact of different parameters. In total, 77 patients were enrolled in the study with 43 patients in the VTD group and 34 patients in the VMP group. Clinical presentations were similar without significant difference, except the VTD group had a higher survival rate (p = 0.029). Comparisons of the two groups over an eight-month time horizon revealed a significant lower mean of direct medical costs in the VTD group than in the VMP group (p < 0.001), and a significantly higher average QALY was gained (p < 0.001). CONCLUSIONS: The study demonstrated the greater clinical benefit and cost-effectiveness of VTD compared to VMP therapy in transplant-ineligible, newly diagnosed myeloma patients.

5.
Emerg Infect Dis ; 28(3): 599-607, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35195517

RESUMO

Vancomycin-resistant Clostridium innocuum was recently identified as an etiologic agent for antibiotic-associated diarrhea in humans. We conducted a case-control study involving 152 C. innocuum-infected patients during 2014-2019 in Taiwan, using 304 cases of Clostridioides difficile infection (CDI) matched by diagnosis year, age (+2 years), and sex as controls. The baseline characteristics were similar between the 2 groups. C. innocuum-infected patients experienced more extraintestinal clostridial infection and gastrointestinal tract-related complications than did patients with CDI. The 30-day mortality rate among C. innocuum-infected patients was 14.5%, and the overall rate was 23.0%. Chronic kidney disease, solid tumor, intensive care unit admission, and shock status were 4 independent risk factors for death. C. innocuum identified from clinical specimens should be recognized as a pathogen requiring treatment, and because of its intrinsic vancomycin resistance, precise identification is necessary to guide appropriate and timely antimicrobial therapy.


Assuntos
Infecções por Clostridium , Firmicutes , Antibacterianos/uso terapêutico , Estudos de Casos e Controles , Pré-Escolar , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/epidemiologia , Humanos , Taiwan/epidemiologia
6.
Sci Rep ; 12(1): 2888, 2022 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-35190605

RESUMO

The larval stage of Japanese eel travels a substantial distance over a long duration through the North Equatorial Current (NEC) and the Kuroshio, and the spawning behavior of mature eels leads to monthly arrival waves in eastern Taiwan between November and February. The total length (TL) of the glass eel relates to its larval duration and age; therefore, the TL can indicate the larval duration. The monthly mean TLs of eels along eastern Taiwan from 2010 to 2021 were used to estimate the batch age, and the recruitment patterns and relative abundances were compared. The TLs of glass eels followed a normal distribution, and the estimated ages were highly correlated with their mean TLs. Early recruit TLs were significantly greater than those of late recruits. The mean tracer drift time was longer in early recruitment months (November-December) than in later dates (February-March). The recruitment lag between Taiwan and Japan was approximately 1-1.5 months, with relative more abundance in Taiwan for the early recruits and in Japan for the late recruits. Speculated cohorts followed the main streams of the NEC and Kuroshio, and the monthly velocity changes of these currents could affect the mean TLs as well as the distribution patterns of Japanese glass eels in Taiwan and Japan.


Assuntos
Tamanho Corporal , Enguias/anatomia & histologia , Larva/anatomia & histologia , Água do Mar , Movimentos da Água , Animais , Enguias/fisiologia , Japão , Larva/fisiologia , Taiwan , Fatores de Tempo
7.
J Cell Physiol ; 237(1): 1033-1043, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34541678

RESUMO

The Golgi apparatus (GA) translocates to the cell leading end during directional migration, thereby determining cell polarity and transporting essential factors to the migration apparatus. The study provides mechanistic insights into how GA repositioning (GR) is regulated. We show that the methyltransferase PRMT5 methylates the microtubule regulator HURP at R122. The HURP methylation mimicking mutant 122F impairs GR and cell migration. Mechanistic studies revealed that HURP 122F or endogenous methylated HURP, that is, HURP m122, interacts with acetyl-tubulin. Overexpression of HURP 122F stabilizes the bundling pattern of acetyl-tubulin by decreasing the sensitivity of the latter to a microtubule disrupting agent nocodazole. HURP 122F also rigidifies GA via desensitizing the organelle to several GA disrupting chemicals. Similarly, the acetyl-tubulin mimicking mutant 40Q or tubulin acetyltransferase αTAT1 can rigidify GA, impair GR, and retard cell migration. Reversal of HURP 122F-induced GA rigidification, by knocking down GA assembly factors such as GRASP65 or GM130, attenuates 122F-triggered GR and cell migration. Remarkably, PRMT5 is found downregulated and the level of HURP m122 is decreased during the early hours of wound healing-based cell migration, collectively implying that the PRMT5-HURP-acetyl-tubulin axis plays the role of brake, preventing GR and cell migration before cells reach empty space.


Assuntos
Microtúbulos , Tubulina (Proteína) , Movimento Celular , Polaridade Celular , Complexo de Golgi , Proteínas de Neoplasias/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Tubulina (Proteína)/genética
8.
Cancer Med ; 11(3): 555-570, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34913612

RESUMO

BACKGROUND: Gastric diffuse large B-cell lymphoma (DLBCL) is often associated with Helicobacter pylori (H. pylori) infection. Those in the early stage could be treated with H. pylori eradication therapy, and are classified into a sensitive group and a resistant group. METHODS: Genome-wide miRNA and miRNA expression profiles were obtained from biopsy specimens of gastric DLBCL. MiRNAs and their targets as predictors of responses to H. pylori eradication therapy were identified through differential expression and pathway enrichment analysis, and further confirmed with transfection experiments in lymphoma cell lines of B-cell origin. RESULTS: Genome-wide miRNA and mRNA profiles showed miR-200 was associated with the sensitive group, and that the resistant group had higher levels of miR-155 and lower levels of DEPTOR (an inhibitor of mTOR) than the sensitive group. BJAB cells transfected with miR-155 also had lower DEPTOR and higher mTOR levels. Therefore, miR-155-mediated inhibition of DEPTOR with secondary activation of mTOR was a potential marker for resistance to H. pylori eradication therapy. In contrast, pathway enrichment analysis showed that Toll-like receptor 5 (TLR5), the receptor for bacterial flagellin, was a potential marker for sensitivity to H. pylori eradication therapy. In an independent series, stronger expression of pS6K1 (a direct target of mTOR) was associated with the resistant group and morphologic evidence of active gastritis was associated with the sensitive group. CONCLUSIONS: These findings showed that activation of the miR-155-DEPTOR pathway is a marker for resistance to H. pylori eradication therapy, and that histological evaluation of active gastritis might be used as a surrogate marker to predict responses to H. pylori eradication therapy in gastric DLBCL.


Assuntos
Gastrite , Infecções por Helicobacter , Helicobacter pylori , Linfoma Difuso de Grandes Células B , MicroRNAs , Neoplasias Gástricas , Gastrite/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/genética , Helicobacter pylori/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma não Hodgkin , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiologia , Serina-Treonina Quinases TOR/metabolismo , Receptor 5 Toll-Like/metabolismo
9.
Vasc Health Risk Manag ; 17: 389-394, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34262283

RESUMO

BACKGROUND: The World Health Organization (WHO) proposed the integrated care for older people (ICOPE) screening tool to identify functional impairment. We explore the association of geriatric functional impairment and hypertension, diabetes, dyslipidemia in the community-dwelling elderly. METHODS: We enrolled individuals aged at least 65 with hypertension, diabetes, or dyslipidemia; or those aged at least 75 from May to July 2019. We applied ICOPE tools to evaluate six function assessments: cognitive decline, limited mobility, malnutrition, visual impairment, hearing loss, and depressive symptoms. Factors were analyzed using stepwise multivariable linear regression for ICOPE scores and logistic regression for geriatric functional impairment. All analyses were adjusted for age and glomerular filtration rate. RESULTS: We enrolled 457 participants including 303 (66.3%) participants with hypertension, 296 (64.8%) diabetes, and 221 (48.4%) dyslipidemia. Seventy-eight (17.1%) participants have at least one geriatric functional impairment, including 41 (25.9%) participants aged ≥ 75 and 37 (12.4%) aged 65-74. The ICOPE score (0.4 ± 0.6) of participants aged at least 75 was higher than that (0.1 ± 0.4) of the participants aged 65-74 (p < 0.001). Dyslipidemia (p = 0.002) was positively associated with ICOPE score. Dyslipidemia (odds ratio: 2.15, 95% confidence interval: 1.27-3.70, p = 0.005), not hypertension (p = 0.3) and diabetes (p = 0.9), was associated with geriatric functional impairment. Visual impairment was the most common function impairment. Female was linked to limited mobility, renal function was associated with mobility (p < 0.001) and nutrition (p = 0.02). CONCLUSION: Dyslipidemia but not hypertension, diabetes is linked to geriatric functional impairment in community-dwelling elderly. Lower renal function is associated with decreased mobility and nutrition. More studies are needed to determine if treatment of dyslipidemia reduces geriatric functional impairment.


Assuntos
Dislipidemias/diagnóstico , Idoso Fragilizado , Fragilidade/diagnóstico , Avaliação Geriátrica , Vida Independente , Afeto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cognição , Estudos Transversais , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus/psicologia , Dislipidemias/fisiopatologia , Dislipidemias/psicologia , Dislipidemias/terapia , Feminino , Fragilidade/fisiopatologia , Fragilidade/psicologia , Fragilidade/terapia , Estado Funcional , Taxa de Filtração Glomerular , Audição , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Hipertensão/psicologia , Rim/fisiopatologia , Masculino , Saúde Mental , Limitação da Mobilidade , Estado Nutricional , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Visão Ocular
10.
Elife ; 102021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34114565

RESUMO

Plexins are semaphorin receptors that play essential roles in mammalian neuronal axon guidance and in many other important mammalian biological processes. Plexin signaling depends on a semaphorin-induced dimerization mechanism and is modulated by small GTPases of the Rho family, of which RND1 serves as a plexin activator yet its close homolog RhoD an inhibitor. Using molecular dynamics (MD) simulations, we showed that RND1 reinforces the plexin dimerization interface, whereas RhoD destabilizes it due to their differential interaction with the cell membrane. Upon binding plexin at the Rho-GTPase-binding domain (RBD), RND1 and RhoD interact differently with the inner leaflet of the cell membrane and exert opposite effects on the dimerization interface via an allosteric network involving the RBD, RBD linkers, and a buttress segment adjacent to the dimerization interface. The differential membrane interaction is attributed to the fact that, unlike RND1, RhoD features a short C-terminal tail and a positively charged membrane interface.


Assuntos
Semaforinas/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Axônios/metabolismo , Humanos , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Neurônios/metabolismo , Ligação Proteica , Multimerização Proteica , Transdução de Sinais , Proteínas rho de Ligação ao GTP/química
11.
J Geophys Res Atmos ; 126(4): e2020JD033586, 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33816041

RESUMO

This study examines the modifications of air-sea coupling processes by dust-radiation-cloud interactions over the North Atlantic Ocean using a high-resolution coupled atmosphere-wave-ocean-dust (AWOD) regional model. The dust-induced mechanisms that are responsible for changes of sea surface temperature (SST) and latent and sensible heat fluxes (LHF/SHF) are also examined. Two 3-month numerical experiments are conducted, and they differ only in the activation and deactivation of dust-radiation-cloud interactions. Model results show that the dust significantly reduces surface downward radiation fluxes (SDRF) over the ocean with the maximum change of 20-30 W m-2. Over the dust plume region, the dust effect creates a low-pressure anomaly and a cyclonic circulation anomaly, which drives a positive wind stress curl anomaly, thereby reducing sea surface height and mixed layer depth. However, the SST change by dust, ranging from -0.5 to 0.5 K, has a great spatial variation which differs from the dust plume shape. Dust cools SST around the West African coast, except under the maximum dust plume ridge, and extends westward asymmetrically along the northern and southern edges of the dust plume. Dust unexpectedly warms SST over a large area of the western tropical North Atlantic and north of the dust plume. These SST changes are controlled by different mechanisms. Unlike the SST change pattern, the LHF and SHF changes are mostly reduced underneath the dust plume region, though they are different in detail due to different dominant factors, and increased south of the dust plume over the tropic.

12.
Nature ; 589(7842): 456-461, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33328639

RESUMO

Autophagy, a process of degradation that occurs via the lysosomal pathway, has an essential role in multiple aspects of immunity, including immune system development, regulation of innate and adaptive immune and inflammatory responses, selective degradation of intracellular microorganisms, and host protection against infectious diseases1,2. Autophagy is known to be induced by stimuli such as nutrient deprivation and suppression of mTOR, but little is known about how autophagosomal biogenesis is initiated in mammalian cells in response to viral infection. Here, using genome-wide short interfering RNA screens, we find that the endosomal protein sorting nexin 5 (SNX5)3,4 is essential for virus-induced, but not for basal, stress- or endosome-induced, autophagy. We show that SNX5 deletion increases cellular susceptibility to viral infection in vitro, and that Snx5 knockout in mice enhances lethality after infection with several human viruses. Mechanistically, SNX5 interacts with beclin 1 and ATG14-containing class III phosphatidylinositol-3-kinase (PI3KC3) complex 1 (PI3KC3-C1), increases the lipid kinase activity of purified PI3KC3-C1, and is required for endosomal generation of phosphatidylinositol-3-phosphate (PtdIns(3)P) and recruitment of the PtdIns(3)P-binding protein WIPI2 to virion-containing endosomes. These findings identify a context- and organelle-specific mechanism-SNX5-dependent PI3KC3-C1 activation at endosomes-for initiation of autophagy during viral infection.


Assuntos
Autofagia/imunologia , Nexinas de Classificação/metabolismo , Vírus/imunologia , Animais , Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proteína Beclina-1/metabolismo , Linhagem Celular , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Endossomos/metabolismo , Feminino , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Interferente Pequeno/genética , Nexinas de Classificação/deficiência , Nexinas de Classificação/genética , Proteínas de Transporte Vesicular/metabolismo
13.
J Formos Med Assoc ; 119(8): 1251-1258, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32354691

RESUMO

PURPOSE: To evaluate the accuracy and effectiveness of noncycloplegic and cycloplegic autorefraction using two types of autorefractors (ARs) compared with retinoscopy in children and adolescents. METHODS: This cross-sectional study included 308 students (6-17 years old) from eastern Taiwan. Noncycloplegic and cycloplegic refractive measurements were obtained using open-field AR (Shin-Nippon NVision-K 5001), closed-field AR (Topcon KR-800), and cycloplegic retinoscopy. Three optical components emerged from the measurements: spherical equivalent (M) and two Jackson cross-cylinder values (J0 and J45). Agreement between both ARs and retinoscopy was evaluated using intraclass correlation coefficient. Measurement discrepancies from retinoscopy among different ARs and cycloplegic status were compared using repeated measures ANOVA and receiver operating characteristic curve analysis. RESULTS: Compared with retinoscopy, measurements obtained before and after cycloplegia with both ARs showed excellent reliability for evaluating M and J0 and fair to good results for J45. More myopic results were obtained using KR-800 before cycloplegia; more hyperopic results were obtained using KR-800 and NVision-K 5001 after cycloplegia(all p < 0.05). J45 data obtained using NVision-K 5001 were closest to those obtained by retinoscopy; J0 data obtained using both ARs were comparable with retinoscopy after cycloplegia. NVision-K 5001 outperformed KR-800 in refractive measurements, particularly in hyperopia diagnosis among younger children. CONCLUSIONS: Both autorefractors showed great agreement with retinoscopy. Results obtained using NVision-K 5001 without cycloplegia were most similar to those by retinoscopy, especially for oblique astigmatism and hyperopia detection in younger children. For large vision screening in elementary school, Shin-Nippon NVision-K 5001 might be a more suitable autorefractor.


Assuntos
Erros de Refração , Retinoscopia , Adolescente , Criança , Estudos Transversais , Humanos , Erros de Refração/diagnóstico , Reprodutibilidade dos Testes , Taiwan
14.
Nat Commun ; 11(1): 1953, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327662

RESUMO

Plexins are receptors for semaphorins that transduce signals for regulating neuronal development and other processes. Plexins are single-pass transmembrane proteins with multiple domains in both the extracellular and intracellular regions. Semaphorin activates plexin by binding to its extracellular N-terminal Sema domain, inducing the active dimer of the plexin intracellular region. The mechanism underlying this activation process of plexin is incompletely understood. We present cryo-electron microscopic structure of full-length human PlexinC1 in complex with the viral semaphorin mimic A39R. The structure shows that A39R induces a specific dimer of PlexinC1 where the membrane-proximal domains from the two PlexinC1 protomers are placed close to each other, poised to promote the active dimer of the intracellular region. This configuration is imposed by a distinct conformation of the PlexinC1 extracellular region, stabilized by inter-domain interactions among the Sema and membrane-proximal domains. Our mutational analyses support the critical role of this conformation in PlexinC1 activation.


Assuntos
Receptores Virais/química , Receptores Virais/metabolismo , Semaforinas/química , Semaforinas/metabolismo , Transdução de Sinais , Animais , Células COS , Chlorocebus aethiops , Microscopia Crioeletrônica , Humanos , Ligantes , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Receptores Virais/genética , Relação Estrutura-Atividade
15.
Structure ; 27(5): 725-727, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31067441

RESUMO

The mechanism of GTPase specificity remains incompletely understood. In this issue of Structure, Lin et al. (2019) present crystal structures of Rab35 in complex with two effectors, ACAP2 and RUSC2, respectively, unraveling the molecular basis for the exquisite mutual specificity between Rab35 and these effectors.


Assuntos
Proteínas Ativadoras de GTPase , Proteínas rab de Ligação ao GTP , Fatores de Ribosilação do ADP
16.
Medicine (Baltimore) ; 98(13): e15032, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30921226

RESUMO

RATIONALE: The etiology of anterior corneal opacities and the effect of debridement cannot be determined by biomicroscopy. Optical coherence tomography (OCT) helps identify the character and depth of these lesions. PATIENT CONCERNS: A 45-year-old female complained of progressive blurred vision for a long time. Slit lamp biomicroscopy showed irregular, faint scar-like opacity of anterior cornea in her both eyes. Pentacam Scheimpflug camera tomography showed irregular astigmatism of anterior corneal surface. Anterior segment spectral-domain OCT revealed thickened, hyper-reflective linings, and scattered lesions, mainly in the epithelial layer. DIAGNOSES: Epithelial basement membrane dystrophy (EBMD). INTERVENTION: Epithelial debridement and bandage lenses. OUTCOMES: The cornea became clear and the vision improved soon after debridement. The pathology showed thickened aberrant basement membrane extending into mid-epithelial layer, with microcyst-like lesions also noted. LESSONS: OCT defines the depth of lesions and helps diagnosis and management of EBMD.


Assuntos
Síndrome de Cogan/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Membrana Basal/diagnóstico por imagem , Membrana Basal/cirurgia , Síndrome de Cogan/cirurgia , Córnea/diagnóstico por imagem , Córnea/cirurgia , Desbridamento/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Microscopia com Lâmpada de Fenda/métodos
17.
Sci Rep ; 8(1): 10477, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29992992

RESUMO

FARP1 is a multi-domain protein that is involved in regulating neuronal development through interacting with cell surface proteins such as class A Plexins and SynCAM 1. The N-terminal FERM domain in FARP1 is known to both promote membrane localization and mediate these protein interactions, for which the underlying molecular mechanisms remain unclear. Here we determined the crystal structures of the FERM domain of FARP1 from zebrafish, and those of FARP2 (a close homolog of FARP1) from mouse and zebrafish. These FERM domains adopt the three-leaved clover fold that is typical of all FERM domains. Our structures reveal a positively charged surface patch that is highly conserved in the FERM domain of FARP1 and FARP2. In vitro lipid-binding experiments showed that the FARP1 FERM domain binds specifically to several types of phospholipid, which is dependent on the positively charged surface patch. We further determined through cell-based analyses that this surface patch on the FERM domain underlies the localization of FARP1 to the plasma membrane, and that FERM domain interactions recruit it to postsynaptic sites in neurons.


Assuntos
Membrana Celular/metabolismo , Domínios FERM , Fatores de Troca de Nucleotídeo Guanina Rho/química , Peixe-Zebra/metabolismo , Animais , Sítios de Ligação , Cristalografia por Raios X , Neurônios/metabolismo , Fosfolipídeos/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Terciária de Proteína
18.
ACS Chem Biol ; 13(8): 2247-2260, 2018 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-29878747

RESUMO

Autophagy, a lysosomal degradation pathway, plays a crucial role in cellular homeostasis, development, immunity, tumor suppression, metabolism, prevention of neurodegeneration, and lifespan extension. Thus, pharmacological stimulation of autophagy may be an effective approach for preventing or treating certain human diseases and/or aging. We sought to establish a method for developing new chemical compounds that specifically induce autophagy. To do this, we developed two assays to identify compounds that target a key regulatory node of autophagy induction-specifically, the binding of Bcl-2 (a negative regulator of autophagy) to Beclin 1 (an allosteric modulator of the Beclin 1/VPS34 lipid kinase complex that functions in autophagy initiation). These assays use either a split-luciferase assay to measure Beclin 1/Bcl-2 binding in cells or an AlphaLISA assay to directly measure direct Beclin 1/Bcl-2 binding in vitro. We screened two different chemical compound libraries, comprising ∼300 K compounds, to identify small molecules that disrupt Beclin 1/Bcl-2 binding and induce autophagy. Three novel compounds were identified that directly inhibit Beclin 1/Bcl-2 interaction with an IC50 in the micromolar range and increase autophagic flux. These compounds do not demonstrate significant cytotoxicity, and they exert selectivity for disruption of Bcl-2 binding to the BH3 domain of Beclin 1 compared with the BH3 domain of the pro-apoptotic Bcl-2 family members, Bax and Bim. Thus, we have identified candidate molecules that serve as lead templates for developing potent and selective Beclin 1/Bcl-2 inhibitors that may be clinically useful as autophagy-inducing agents.


Assuntos
Autofagia/efeitos dos fármacos , Proteína Beclina-1/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Mapas de Interação de Proteínas/efeitos dos fármacos
19.
BMC Ophthalmol ; 17(1): 236, 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-29207977

RESUMO

BACKGROUND: AZOOR was first described by Gass in 1993 as a syndrome with rapid loss of one or more extensive zones of the outer retinal segments. It is characterized by photopsia, minimal funduscopic changes, and electroretinographic abnormalities. The efficacy of systemic steroids in treating AZOOR has been previously described and advocated by the concept of autoimmune retinopathy. However, the use of intravitreal of sustained-released steroid had not been mentioned to date. CASE PRESENTATION: A 34-year-old man had sudden onset of central scotoma and photopsia in the left eye. His visual acuity continued deteriorating. The visual field defect demonstrated bilateral enlarged blind spots and altitudinal defects. Fluorescein angiography (FA) showed nonspecific retinal inflammation, and an electroretinogram (ERG) illustrated decreased amplitude of the b wave in both eyes. Optical coherence tomography (OCT) examinations revealed parafoveal loss of the photoreceptor inner/outer segment (IS/OS) junction. Therefore, acute zonal occult outer retinopathy (AZOOR) was diagnosed. Although his vision did not improve under the initial treatment of systemic corticosteroid and calcium channel blocker, remarkable improvement was noticed after the intravitreal injection(IVI) of Ozurdex, consistent with the recovered IS/OS junction disruption. CONCLUSIONS: We herein report a typical case of AZOOR, suggesting that the intravitreal injection of steroid may benefit in certain patients.


Assuntos
Anti-Inflamatórios/administração & dosagem , Dexametasona/administração & dosagem , Escotoma/tratamento farmacológico , Adulto , Humanos , Injeções Intravítreas , Masculino , Resultado do Tratamento , Síndrome dos Pontos Brancos
20.
Nat Cell Biol ; 19(10): 1226-1236, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28945232

RESUMO

Direct interactions between pro- and anti-apoptotic BCL-2 family members form the basis of cell death decision-making at the outer mitochondrial membrane (OMM). Here we report that three anti-apoptotic BCL-2 proteins (MCL-1, BCL-2 and BCL-XL) found untethered from the OMM function as transcriptional regulators of a prosurvival and growth program. Anti-apoptotic BCL-2 proteins engage a BCL-2 homology (BH) domain sequence found in SUFU (suppressor of fused), a tumour suppressor and antagonist of the GLI DNA-binding proteins. BCL-2 proteins directly promote SUFU turnover, inhibit SUFU-GLI interaction, and induce the expression of the GLI target genes BCL-2, MCL-1 and BCL-XL. Anti-apoptotic BCL-2 protein/SUFU feedforward signalling promotes cancer cell survival and growth, and can be disabled with BH3 mimetics-small molecules that target anti-apoptotic BCL-2 proteins. Our findings delineate a chemical strategy for countering drug resistance in GLI-associated tumours and reveal unanticipated functions for BCL-2 proteins as transcriptional regulators.


Assuntos
Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Repressoras/metabolismo , Transcrição Gênica , Proteínas Supressoras de Tumor/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose , Sistemas CRISPR-Cas , Proliferação de Células , Sobrevivência Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Genótipo , Células HEK293 , Humanos , Camundongos , Camundongos Knockout , Camundongos Nus , Mimetismo Molecular , Proteína de Sequência 1 de Leucemia de Células Mieloides/deficiência , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Células NIH 3T3 , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Fragmentos de Peptídeos/metabolismo , Fenótipo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Interferência de RNA , Proteínas Repressoras/genética , Transdução de Sinais , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Transfecção , Proteínas Supressoras de Tumor/genética , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
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