Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Exp Eye Res ; 215: 108906, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34953864

RESUMO

Müller cells maintain homeostatic functions in the retina. Their dysfunction leads to irreversible retinal diseases. Oxidative injury is a leading cause of retinal cytotoxicity. Our previous studies reported several betulinic acid (BA) derivatives can protect Müller cells from oxidative injury but achieving pharmacologically effective concentrations in the Müller cells could be a limitation. To optimise cellular delivery, we encapsulated the BA analogues H3, H5 and H7 into the clinically approved Compritol 888 and HD5 ATO solid lipid nanoparticles (SLNs) using the micro-emulsion method. The cytoprotective effects of these SLN-formulations were determined in human MIO-M1 cells. We found cytoprotection by H3 and H5 SLN-formulations was significantly enhanced, which was evident at concentrations much lower than those required with the free agents. Both SLN-formulations prolonged the duration of action of these agents. The most effective agent H5 delivered in 888 ATO SLNs attenuated glutamate-induced ROS formation and the associated necrosis in MIO-M1 cells. Overall, SLNs have emerged as promising delivery carriers for BA derivatives enhancing their protective effects against oxidative injury in human Müller cells. Our study is the first to show SLNs can be a viable route to delivery agents with improved efficacy and stability into human Müller cells favoring the treatment/prevention of retinal diseases.


Assuntos
Nanopartículas , Doenças Retinianas , Portadores de Fármacos , Células Ependimogliais , Humanos , Lipossomos , Estresse Oxidativo , Triterpenos Pentacíclicos , Ácido Betulínico
2.
Biochem Biophys Res Commun ; 565: 29-35, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34090207

RESUMO

Microtubule-targeting agents (MTAs) are the most commonly used anti-cancer drugs. At least fourteen microtubule inhibitors and ten antibody drug conjugates (ADCs) linking MTAs are approved by FDA for clinical use in cancer therapy. In current research, we determined the crystal structure of tubulysin analogue TGL in complex with tubulin at a high resolution (2.65 Å). In addition, we summarized all of the previously published high-resolution crystal structures of ligands in the vinca site to provide structural insights for the rational design of the new vinca-site ligands. Moreover, based on the aligned results of the vinca site ligands, we provided three possible routes for designing new tubulysin analogues, namely macrocyclization between the N-14 side chain and the N-9 side chain, the hybird of tubulysin M and phomopsin A, and growing new aryl group at C-21. These designed structures will inspire the development of new MTAs or payloads in cancer therapy.


Assuntos
Tubulina (Proteína)/química , Cristalografia por Raios X , Humanos , Modelos Moleculares , Conformação Proteica
3.
Biochem Biophys Res Commun ; 534: 330-336, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33272565

RESUMO

Microtubule is a key component of cytoskeleton and has been considered as an important target for the treatment of cancer. In particular, the tubulin taxane-site inhibitors such as taxol analogs and epothilones have achieved great success in clinical trials. However, the structural basis of many taxane-site inhibitors is still lacking in exploring their mechanism of action. We here reported crystal complex structures for three taxane-site inhibitors, Ixabepilone, Epothilone B, and Epothilone D, which were determined to 2.4 Å, 2.4 Å, and 2.85 Å, respectively. The crystal structures revealed that these taxane-site inhibitors possess similar binding modes to that of Epothilone A at the taxane site, e.g. making critical hydrogen-bonding interactions with multiple residues on the M-loop, which facilitating the tubulin polymerization. Furthermore, we summarized the binding modes of almost all taxane-site inhibitors and identified novel taxane-site ligands with simpler chemical structures through virtual screening. On this basis, new derivatives with higher binding affinity to tubulin were designed and developed, which can form additional hydrogen bond interactions with tubulin. Overall, this work determined the mechanism of action of epothilones and provided a structural basis to design reasonably novel taxane-site inhibitors with simpler structure and improved pharmacokinetic properties.


Assuntos
Epotilonas/química , Epotilonas/farmacologia , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Epotilonas/farmacocinética , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Moduladores de Tubulina/farmacocinética , Interface Usuário-Computador
4.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(4): 521-525, 2020 Jul.
Artigo em Zh | MEDLINE | ID: mdl-32691561

RESUMO

OBJECTIVE: To quantitatively detect GNAQ/11 mutations in uveal melanoma (UM) by droplet digital PCR (ddPCR). METHODS: Formaldehyde-fixed paraffin-embedded (FFPE) tumor samples were taken from 78 UM patients with enucleation in West China Hospital between 2009 and 2015. None of the patients received radiotherapy or chemotherapy before enucleation. A retrospective study was conducted to detect GNAQ/11 mutation in UM by ddPCR. To compare the consistency of the results of the two detection methods, DNA sequencing was performed on the target gene by Sanger sequencing. 78 patients with UM were studied retrospectively. GNAQ/11 mutations in uveal melanoma was detected by ddPCR. The consistency of the results of the two detection methods was analyzed. RESULTS: GNAQ/11 mutations frequency was 91.9%. The consistency test between Sanger sequencing and ddPCR of GNAQ/11 mutations in 74 patients with UM was conducted. Kappa coefficient=0.436, P=0.001. The error rate of Sanger sequencing results was significantly higher in the heterogeneous group than in the homogeneous group (12/37 vs. 3/16, P=0.53), but the difference was not statistically significant. CONCLUSION: The results of ddPCR and Sanger sequencing showed good consistency, and the mutation ratio of GNAQ/11 in UM was significantly different. GNAQ/11 mutation frequency in UM patients detected by ddPCR was close to the reported frequency. It is more recommended to use ddPCR with high sensitivity to detect gene mutations in samples of tumor tissue DNA derived from FFPE. Sanger sequencing is prone to false negative results.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Subunidades alfa de Proteínas de Ligação ao GTP , Melanoma , Mutação , Reação em Cadeia da Polimerase , Neoplasias Uveais , China , DNA/química , Análise Mutacional de DNA , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Melanoma/diagnóstico , Melanoma/genética , Estudos Retrospectivos , Neoplasias Uveais/diagnóstico , Neoplasias Uveais/genética
5.
Exp Eye Res ; 181: 112-119, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30639792

RESUMO

The purpose of this study was to investigate indoleamine 2,3-dioxygenase 1 (IDO1) expression and its implications in uveal melanoma (UM). Bioinformatics analysis was performed on microarray data (GSE22138 and GSE27831) from the Gene Expression Omnibus (GEO) database to evaluate IDO1 expression in mRNA level. Ninety-two cases in the database were divided into the IDO1-high group (46 cases) and IDO1-low group (46 cases). Paraffin embedded tumor sections from 27 patients with UM were studied by immunofluorescence. The mRNA results showed that IDO1 expression was inversely correlated with tumor thickness (9.93 ±â€¯3.33 mm in IDO1-high group vs. 11.56 ±â€¯2.38 mm in IDO1-low group) (p = 0.016) and metastatic rate (30.4% in IDO1-high group vs. 69.6% in IDO1-low group, p < 0.001). The IDO1-high group showed higher immune cell gene expression: CD3D (6.56 ±â€¯1.0 vs. 5.46 ±â€¯0.53, p < 0.0001), CD4 (4.72 ±â€¯0.4 vs. 4.2 ±â€¯0.42, p < 0.0001), and CD68 (6.17 ±â€¯1.23 vs. 5.53 ±â€¯0.77, p = 0.015). Further analysis showed that immune-suppressive T regulatory cell genes (CD3D, CD4, IL2RA and FOXP3) were expressed in 67.4% (31/46) cases in the IDO1-high group and 23.91% (11/46) cases in the IDO1-low group. In addition, IDO1 and interferon gamma (IFNG) mRNA expression were strongly correlated (r = 0.70, p < 0.0001). The correlation analysis of different immune checkpoints showed that IDO1 was positively correlated with CD274(PDL1), but not CTLA4 or PDCD1.The disease-free survival (DFS) in the IDO1-high/IFNG-high group was better than that of the IDO1-low/IFNG-low group. The IDO1 immunostaining result showed that 2 cases in 18 UMs with Bruch's membrane (BM) rupture and 7 out of 9 cases without BM rupture were scored high (Grade 2-3) (p = 0.001). Comparing the immune cells staining results between IDO1-high group and IDO1-low group, higher percentage of patients in the former group had high levels of T cells and macrophages infiltration, but only the difference in macrophage was statistically significant (CD68, 77.78% vs. 27.78%, p = 0.04). The analysis based on GEO data and the result from immunostaining study are consistent with each other. In conclusion, the expression of IDO1 is probably induced by IFNγ from infiltrated immune cells in UM. BM rupture is an important indicator of IDO1 expression level and distribution pattern. The complex role of IDO1 may limit its therapeutic effect in UM.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Melanoma/metabolismo , Neoplasias Uveais/metabolismo , Idoso , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/metabolismo , Feminino , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Neoplasias Uveais/patologia
6.
Biochem Biophys Res Commun ; 495(1): 185-188, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29102632

RESUMO

Microtubules are composed of αß-tubulin heterodimers and have been treated as highly attractive targets for antitumor drugs. A broad range of agents bind to tubulin and interfere with microtubule assembly, including colchicine binding site inhibitors (CBSIs). Tubulin Polymerization Inhibitor I (TPI1), a benzylidene derivative of 9(10H)-anthracenone, is a CBSI that inhibits the assembly of microtubules. However, for a long time, the design and development of anthracenone family drugs have been hindered by the lack of structural information of the tubulin-agent complex. Here we report a 2.3 Å crystal structure of tubulin complexed with TPI1, the first structure of anthracenone family agents. This complex structure reveals the interactions between TPI1 and tubulin, and thus provides insights into the development of new anthracenone derivatives targeting the colchicine binding site.


Assuntos
Antracenos/química , Antracenos/farmacologia , Desenho de Fármacos , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Animais , Sítios de Ligação/efeitos dos fármacos , Bovinos , Galinhas , Colchicina/metabolismo , Cristalografia por Raios X , Humanos , Simulação de Acoplamento Molecular , Ratos , Tubulina (Proteína)/química
7.
Exp Eye Res ; 168: 2-11, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29284110

RESUMO

Neovascular age-related macular degeneration (AMD) is a leading cause of vision loss worldwide. Although intravitreal injection of anti-VEGF antibodies and VEGF Trap have significant clinical benefits, the complications of intravitreal injection, drug resistance and patient compliance still need to be concerned. In this study, the effects of an orally administered multi-targeted tyrosine kinase inhibitor (Lenvatinib, E7080) were evaluated in vitro and in vivo on neovascular AMD mouse model. The results showed that E7080 effectively inhibited the proliferation, migration and tubule formation of human choroidal microvascular endothelial cells (HCMECs), and suppressed the angiogenesis of zebrafish subintestinal vessels without causing malformation. The anti-angiogenic effect of E7080 on the laser-induced choroidal neovascularization (CNV) mouse model by oral administration of 10 mg/kg/day was observed. The fluorescein angiography showed CNV leakage area in treatment group vs control group was 3.407 ±â€¯0.2939 vs 5.202 ±â€¯0.9001 (P = .0133) at day 7th post laser-induced CNV, 1.138 ±â€¯0.4334 vs 3.122 ±â€¯0.3466 (P = .0064) at day 14th, 1.401 ±â€¯0.6577 vs 2.781 ±â€¯0.9815 (P = .00262) at day 21th respectively. Moreover, pharmacokinetics analysis in rat retina showed that E7080 rapidly penetrated the blood-retina barrier to retina through oral administration. The T1/2 in retina was 3.81 ±â€¯0.77 h, the Tmax was 4.60 ±â€¯0.73 h, the AUC0-∞ was 110448.51 ± 18532.51 h*ng/g after a single dose administration analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). In conclusion, our study suggested that orally administered E7080 can be a novel therapeutic strategy for neovascular AMD.


Assuntos
Inibidores da Angiogênese/farmacologia , Neovascularização de Coroide/tratamento farmacológico , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinolinas/farmacologia , Degeneração Macular Exsudativa/tratamento farmacológico , Administração Oral , Análise de Variância , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Humanos , Camundongos , Fator A de Crescimento do Endotélio Vascular/metabolismo
8.
Biomedicines ; 11(6)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37371607

RESUMO

Age-related diseases, such as Parkinson's disease, Alzheimer's disease, cardiovascular diseases, cancers, and age-related macular disease, have become increasingly prominent as the population ages. Oxygen is essential for living organisms, but it may also cause disease when it is transformed into reactive oxygen species via biological processes in cells. Most of the production of ROS occurs in mitochondrial complexes I and III. The accumulation of ROS in cells causes oxidative stress, which plays a crucial role in human ageing and many diseases. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key antioxidant transcription factor that plays a central role in many diseases and ageing in general. It regulates many downstream antioxidative enzymes when cells are exposed to oxidative stress. A basic-region leucine zipper (bZIP) transcription factor, MAF, specifically the small MAF subfamily (sMAFs), forms heterodimers with Nrf2, which bind with Maf-recognition elements (MAREs) in response to oxidative stress. The role of this complex in the human retina remains unclear. This review summarises the current knowledge about Nrf2 and its downstream signalling, especially its cofactor-MAF, in ageing and diseases, with a focus on the retina. Since Nrf2 is the master regulator of redox homeostasis in cells, we hypothesise that targeting Nrf2 is a promising therapeutic approach for many age-related diseases.

9.
Adv Drug Deliv Rev ; 199: 114965, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37315899

RESUMO

The delivery of cures for retinal diseases remains problematic. There are four main challenges: passing through multiple barriers of the eye, the delivery to particular retinal cell types, the capability to carry different forms of therapeutic cargo and long-term therapeutic efficacy. Lipid-based nanoparticles (LBNPs) are potent to overcome these challenges due to their unique merits: amphiphilic nanoarchitectures to pass biological barriers, vary modifications with specific affinity to target cell types, flexible capacity for large and mixed types of cargos and slow-release formulations for long-term treatment. We have reviewed the latest research on the applications of LBNPs for treating retinal diseases and categorized them by different payloads. Furthermore, we identified technical barriers and discussed possible future development for LBNPs to expand the therapeutic potential in treating retinal diseases.


Assuntos
Nanopartículas , Doenças Retinianas , Humanos , Portadores de Fármacos/uso terapêutico , Lipídeos/uso terapêutico , Lipossomos , Doenças Retinianas/tratamento farmacológico , Sistemas de Liberação de Medicamentos
10.
Antioxidants (Basel) ; 11(5)2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35624805

RESUMO

The human retina, which is part of the central nervous system, has exceptionally high energy demands that requires an efficient metabolism of glucose, lipids, and amino acids. Dysregulation of retinal metabolism disrupts local energy supply and redox balance, contributing to the pathogenesis of diverse retinal diseases, including age-related macular degeneration, diabetic retinopathy, inherited retinal degenerations, and Macular Telangiectasia. A better understanding of the contribution of dysregulated metabolism to retinal diseases may provide better therapeutic targets than we currently have.

11.
Redox Biol ; 54: 102379, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35779441

RESUMO

The Pentose Phosphate Pathway (PPP), a metabolic offshoot of the glycolytic pathway, provides protective metabolites and molecules essential for cell redox balance and survival. Transketolase (TKT) is the critical enzyme that controls the extent of "traffic flow" through the PPP. Here, we explored the role of TKT in maintaining the health of the human retina. We found that Müller cells were the primary retinal cell type expressing TKT in the human retina. We further explored the role of TKT in human Müller cells by knocking down its expression in primary cultured Müller cells (huPMCs), isolated from the human retina (11 human donors in total), under light-induced oxidative stress. TKT knockdown and light stress reduced TKT enzymatic activities and the overall metabolic activities of huPMCs with no detectable cell death. TKT knockdown restrained the PPP traffic flow, reduced the expression of NAD(P)H Quinone Dehydrogenase 1 (NQO1), impaired the antioxidative response of NRF2 to light stress and aggravated the endoplasmic reticulum (ER) stress. TKT knockdown also inhibited overall glucose intake, reduced expression of Dihydrolipoamide dehydrogenase (DLD) and impaired the energy supply of the huPMCs. In summary, Müller cell-mediated TKT activity plays a critical protective role in the stressed retina. Knockdown of TKT disrupted the PPP and impaired overall glucose utilisation by huPMCs and rendered huPMCs more vulnerable to light stress by impairing energy supply and antioxidative NRF2 responses.


Assuntos
Fator 2 Relacionado a NF-E2 , Transcetolase , Células Ependimogliais/metabolismo , Glucose/metabolismo , Humanos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Via de Pentose Fosfato , Pentoses , Fosfatos , Transcetolase/genética , Transcetolase/metabolismo
12.
Theranostics ; 12(15): 6705-6722, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36185611

RESUMO

Rationale: Müller cells play an essential role in maintaining the health of retinal photoreceptors. Dysfunction of stressed Müller cells often results in photoreceptor degeneration. However, how these cells communicate under stress and the signalling pathways involved remain unclear. In this study, we inhibited the MAPK (ERK1/2) signalling, mainly activated in Müller cells, evaluated the protective effects on the photoreceptors and further explored the signalling communication between stressed Müller cells and degenerating photoreceptors. Methods: We evaluated the changes of MAPK (ERK1/2) signalling and its downstream targets in human retinal explants treated with PD98059, a specific phosphorylated ERK1/2 inhibitor, by western blot and immunostaining. We further assessed photoreceptor degeneration by TUNEL staining and outer nuclear layer thickness. We also injected PD98059 into the eyes of mice exposed to photo-oxidative stress. We evaluated the protective effects on photoreceptor degeneration by optical coherence tomography (OCT) and electroretinography (ERG). The crosstalk between Müller cells and photoreceptors was further dissected based on the changes of transcription factors by RNA sequencing and protein profiles of multiple signalling pathways. Results: We found that MAPK (ERK1/2) signalling was mainly activated in Müller cells under stress, both ex vivo and in vivo. PD98059 inhibited the phosphorylation of ERK1/2, reduced expression of the gliotic marker glial fibrillary acidic protein (GFAP) in Müller cells and increased levels of the neuroprotective factor, interphotoreceptor retinoid-binding protein (IRBP) in photoreceptors. Inhibition of pERK1/2 also reduced retinal photo-oxidative damage in mice retinas assessed by OCT and ERG. We also identified that the JAK/STAT3 signalling pathway might mediate signalling transduction from Müller cells to photoreceptors. Conclusion: MAPK (ERK1/2) deactivation through chemical inhibition, mainly in stressed Müller cells, can alleviate gliosis in Müller cells and restore the expression of IRBP in photoreceptors, which appears to prevent retinal degeneration. Our findings suggested a new way to prevent photoreceptor degeneration by manipulating the stress response in Müller cells.


Assuntos
Degeneração Retiniana , Animais , Células Ependimogliais , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Degeneração Retiniana/genética , Fatores de Transcrição/metabolismo
13.
Bio Protoc ; 11(19): e4179, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34722826

RESUMO

Muller cells, the major glial cells of the retina, play vital roles in maintaining redox homeostasis and retinal metabolism. An immortalized human Muller cell line (MIO-M1) is widely used as an in vitro model to study Muller cells' function, but they may not be exactly the same as primarily cultured human Muller cells. The use of human primary Muller cells (huPMCs) in culture has been limited by the requirement for complicated culture systems or particular age ranges of donors. We have successfully grown huPMCs using our established protocol. The cell type was pure, and cultured cells expressed Muller cell-specific markers strongly. The cultured huPMCs were used for morphologic, metabolic, transcriptomic, and functional studies. Graphic abstract: Timeline for human primary Muller cell (huPMC) culture.

14.
Front Cell Neurosci ; 14: 577935, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33328889

RESUMO

Interphotoreceptor retinoid-binding protein (IRBP), also known as retinol binding protein 3 (RBP3), is a lipophilic glycoprotein specifically secreted by photoreceptors. Enriched in the interphotoreceptor matrix (IPM) and recycled by the retinal pigment epithelium (RPE), IRBP is essential for the vision of all vertebrates as it facilitates the transfer of retinoids in the visual cycle. It also helps to transport lipids between the RPE and photoreceptors. The thiol-dependent antioxidant activity of IRBP maintains the delicate redox balance in the normal retina. Thus, its dysfunction is suspected to play a role in many retinal diseases. We have reviewed here the latest research on IRBP in both retinal health and disease, including the function and regulation of IRBP under retinal stress in both animal models and the human retina. We have also explored the therapeutic potential of targeting IRBP in retinal diseases. Although some technical barriers remain, it is possible that manipulating the expression of IRBP in the retina will rescue or prevent photoreceptor degeneration in many retinal diseases.

15.
iScience ; 23(11): 101672, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33196018

RESUMO

Photoreceptors, especially cones, which are enriched in the human macula, have high energy demands, making them vulnerable to metabolic stress. Metabolic dysfunction of photoreceptors and their supporting retinal pigment epithelium (RPE) is an important underlying cause of degenerative retinal diseases. However, how cones and the macula support their exorbitant metabolic demand and communicate with RPE is unclear. By profiling metabolite uptake and release and analyzing metabolic genes, we have found cone-rich retinas and human macula share specific metabolic features with upregulated pathways in pyruvate metabolism, mitochondrial TCA cycle, and lipid synthesis. Human neural retina and RPE have distinct but complementary metabolic features. Retinal metabolism centers on NADH production and neurotransmitter biosynthesis. The retina needs aspartate to sustain its aerobic glycolysis and mitochondrial metabolism. RPE metabolism is directed toward NADPH production and biosynthesis of acetyl-rich metabolites, serine, and others. RPE consumes multiple nutrients, including proline, to produce metabolites for the retina.

16.
Elife ; 82019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31036157

RESUMO

The human macula is more susceptible than the peripheral retina to developing blinding conditions such as age-related macular degeneration, diabetic retinopathy. A key difference between them may be the nature of their Müller cells. We found primary cultured Müller cells from macula and peripheral retina display significant morphological and transcriptomic differences. Macular Müller cells expressed more phosphoglycerate dehydrogenase (PHGDH, a rate-limiting enzyme in serine synthesis) than peripheral Müller cells. The serine synthesis, glycolytic and mitochondrial function were more activated in macular than peripheral Müller cells. Serine biosynthesis is critical in defending against oxidative stress. Intracellular reactive oxygen species and glutathione levels were increased in primary cultured macular Müller cells which were more susceptible to oxidative stress after inhibition of PHGDH. Our findings indicate serine biosynthesis is a critical part of the macular defence against oxidative stress and suggest dysregulation of this pathway as a potential cause of macular pathology.


Assuntos
Células Ependimogliais/metabolismo , Estresse Oxidativo/fisiologia , Retina/metabolismo , Serina/biossíntese , Células Ependimogliais/citologia , Regulação da Expressão Gênica , Glutationa/metabolismo , Humanos , Mitocôndrias/metabolismo , Fosfoglicerato Desidrogenase , Espécies Reativas de Oxigênio/metabolismo , Serina/genética , Transcriptoma
17.
Br J Pharmacol ; 176(12): 2063-2078, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30825184

RESUMO

BACKGROUND AND PURPOSE: Simvastatin is a 3-hydroxy-3-methylglutaryl CoA reductase inhibitor with multiple targets and effects. It protects neurons in the brain, but its protective effects on photoreceptors are unclear. In this study, we evaluated the neuroprotective effect of simvastatin on photoreceptors exposed to stress induced by all-trans-retinal (atRAL). EXPERIMENTAL APPROACH: AlamarBlue and LDH assays were used to evaluate the viability and metabolic activity of Y79 cells (a retinoblastoma cell line) exposed to atRAL-induced stress with or without simvastatin pretreatment. Changes in cellular ROS were evaluated using flow cytometry and mitochondrial stress markers JC-1 and HSP60. Changes in levels of two photoreceptor-specific markers, cone-rod homeobox protein (CRX) and interphotoreceptor retinoid binding protein (IRBP), were evaluated with western blot. The results were validated in ex vivo human retinal explants and a mouse model of photoreceptor degeneration. KEY RESULTS: Simvastatin improved mitochondrial function, alleviated oxidative stress and up-regulated the photoreceptor-specific markers IRBP and its upstream regulator CRX in Y79 cells and ex vivo human retinal explants under atRAL-induced stress. Simvastatin attenuated photoreceptor degeneration in association with up-regulation of IRBP and CRX expression after knockdown of IRBP in a murine model. CONCLUSION AND IMPLICATIONS: Our findings suggest that simvastatin has a novel role in protecting photoreceptors from atRAL-induced stress. Simvastatin treatment resulted in up-regulation of IRBP and its upstream transcription factor CRX in Y79 cells, ex vivo human retinal explants, and murine retinas in vivo. Further studies of simvastatin to treat photoreceptor degeneration are warranted.


Assuntos
Substâncias Protetoras/farmacologia , Células Fotorreceptoras Retinianas Cones/efeitos dos fármacos , Proteínas de Ligação ao Retinol/metabolismo , Sinvastatina/farmacologia , Animais , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Injeções Intraperitoneais , Camundongos , Camundongos Transgênicos , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/administração & dosagem , Células Fotorreceptoras Retinianas Cones/metabolismo , Sinvastatina/administração & dosagem , Relação Estrutura-Atividade , Tamoxifeno/administração & dosagem , Tamoxifeno/farmacologia , Tretinoína/farmacologia , Regulação para Cima/efeitos dos fármacos
18.
Ophthalmic Surg Lasers Imaging Retina ; 49(6): 416-424, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29927469

RESUMO

BACKGROUND AND OBJECTIVE: This systematic review and meta-analysis was made to measure risk factors for retinal redetachment (re-RD) after silicone oil removal (SOR) in a quantitative method. PATIENTS AND METHODS: A comprehensive literature review relating to risk factors for re-RD after SOR was conducted before March 2017. Odds ratio (OR) with 95% confidence interval (CI) was calculated after data combination. RESULTS: Sixteen studies were included, and risk factors with significant differences found between the re-RD and control groups are as follows: aphakic eye (OR = 1.50), high myopia (OR = 2.47), previous failed retinal surgery (OR = 1.71), and ocular trauma (OR = 3.52). Peripheral 360° laser retinopexy (OR = 0.40) and scleral encircling band (OR = 0.58) were found to be protective factors of re-RD after SOR. CONCLUSION: Aphakic eye, high myopia, previous failed retinal surgery, ocular trauma, lack of 360° laser, and scleral encircling band were possible risk factors relating to the occurrence of re-RD after SOR. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:416-424.].


Assuntos
Complicações Pós-Operatórias/etiologia , Descolamento Retiniano/cirurgia , Óleos de Silicone/administração & dosagem , Vitrectomia/métodos , Afacia/complicações , Traumatismos Oculares/complicações , Humanos , Miopia Degenerativa/complicações , Recidiva , Fatores de Risco
19.
J Hum Lact ; 34(3): 424-432, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29932861

RESUMO

BACKGROUND: Aesthetic breast implant augmentation surgery is the most popular plastic surgery worldwide. Many women choose to receive breast implants during their reproductive ages, although the long-term effects are still controversial. Research aim: We conducted a meta-analysis to assess the influence of aesthetic breast augmentation on breastfeeding. We also compared the exclusive breastfeeding rates of periareolar versus inframammary incision. METHODS: A systematic search for comparative studies about breast implants and breastfeeding was performed in PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ScienceDirect, Scopus, and Web of Science through May 2018. Meta-analysis was conducted with a random-effects model (or fixed effects, if heterogeneity was absent). RESULTS: Four cohorts and one cross-sectional study were included. There was a significant reduction in the exclusive breastfeeding rate for women with breast implants compared with women without implants, pooled relative risk = 0.63, 95% confidence interval [0.46, 0.86], as well as the breastfeeding rate, pooled relative risk = 0.88, 95% confidence interval [0.81, 0.95]. There was no evidence that periareolar incision was associated with a reduction in the exclusive breastfeeding rate, pooled relative risk = 0.84, 95% confidence interval [0.45, 1.58]. CONCLUSION: Participants with breast implants are less likely to establish breastfeeding, especially exclusive breastfeeding. Periareolar incision does not appear to reduce the exclusive breastfeeding rate.


Assuntos
Aleitamento Materno/métodos , Implantes de Mama/efeitos adversos , Humanos
20.
J Ophthalmol ; 2018: 2501325, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30607294

RESUMO

PURPOSE: To investigate the effect of cataract surgery on subfoveal choroid thickness (SFCT) using enhanced-depth imaging optical coherence tomography (EDI-OCT). MATERIALS AND METHODS: Relevant publications were searched systematically through various databases from inception to March 2018. The unit of choroidal thickness measurements is micrometers. Studies comparing SFCT before and after cataract surgery were retrieved. All qualified articles were analyzed using RevMan 5.3. RESULTS: A total of 13 studies with 802 eyes from 646 patients were identified for inclusion. There was a significant increase of SFCT at 1 week (MD = 6.62, 95% CI: 1.20-12.05, P=0.02, I2 = 0%), 1 month (MD = 8.30, 95% CI: 3.20-13.39, P=0.001, I2 = 0%), and 3 months (MD = 8.28, 95% CI: 1.84-14.73, P=0.01, I2 = 0%) after cataract surgery. In subgroup analysis, SFCT in Asians and patients without nonsteroidal anti-inflammatory drugs (NSAIDs) in postoperative medication was significantly thicker (P < 0.05). No statistically significant increase of SFCT was found in diabetic mellitus (DM) patients for 1 day (P=0.89), 1 week (P=0.59), 1 month (P=0.52), and 3 months (P=0.42) after cataract surgery. CONCLUSIONS: This meta-analysis suggested that SFCT increased since 1 week after the cataract surgery and the increase lasted for at least 3 months. Asians and patients without NSAIDs in postoperative medication were more likely to have a thicker SFCT after cataract surgery, whereas DM patients were less likely to increase in SFCT.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA