Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Exp Eye Res ; 165: 47-58, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28893564

RESUMO

The principle reason of high failure rate of glaucoma filtration surgery is the loss of filtration function caused by postoperative scar formation. We investigated the effects of 5-aza-2'-deoxycytidine (5-Aza-dc), a DNA methyltransferases inhibitor, on human Tenon's capsule fibroblasts (HTFs) differentiation and fibrosis and its mechanism of action, especially in relation to transforming growth factor (TGF)-ß1 signaling. TGF-ß1 was used to induce differentiation of cultured HTFs. 5-Aza-dc suppressed DNA methyltransferases (DNMTs) activity 6 h after treatment with a course corresponding to that of TGF-ß1-induced reduction of DNMT activity without affecting cell viability as measured by Cell Counting Kit-8 assay. 5-Aza-dc also reduced DNMT1 and DNMT3a protein expression from 24 to 48 h. HTFs migration evaluated by scratch-wound assay were significantly increased 24 h after 5-Aza-dc treatment, a time course similar to that of TGF-ß1. Treatment with 5-Aza-dc significantly increased the mRNA and protein levels of α-smooth muscle actin (α-SMA), collagen-1A1 (Col1A1), fibronectin (FN) and TGF-ß type I receptor (TGFßRI). Furthermore, the effects of 5-Aza-dc on DNMT activity suppression, cell migration, and fibrosis were all reversed by a TGFßRI inhibitor- SB-431542. Meanwhile, knockdown of DNMT1 upregulated TGFßRI expression and had the same fibrosis-inducing effect in HTFs, which was also inhibited by SB-431542. Thus, the results indicate that DNA hypomethylation induces HTFs differentiation and fibrosis through up-regulation of TGFßRI. DNA methylation status plays an important role in subconjunctival wound healing.


Assuntos
Azacitidina/análogos & derivados , Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibrose/patologia , Cápsula de Tenon/citologia , Adulto , Azacitidina/farmacologia , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , DNA (Citosina-5-)-Metiltransferase 1/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA/efeitos dos fármacos , DNA Metiltransferase 3A , Decitabina , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Proteínas Repressoras/metabolismo , Cápsula de Tenon/metabolismo , Fator de Crescimento Transformador beta , Regulação para Cima/efeitos dos fármacos
2.
Nat Commun ; 14(1): 5144, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37620313

RESUMO

Human reasoning is grounded in an ability to identify highly abstract commonalities governing superficially dissimilar visual inputs. Recent efforts to develop algorithms with this capacity have largely focused on approaches that require extensive direct training on visual reasoning tasks, and yield limited generalization to problems with novel content. In contrast, a long tradition of research in cognitive science has focused on elucidating the computational principles underlying human analogical reasoning; however, this work has generally relied on manually constructed representations. Here we present visiPAM (visual Probabilistic Analogical Mapping), a model of visual reasoning that synthesizes these two approaches. VisiPAM employs learned representations derived directly from naturalistic visual inputs, coupled with a similarity-based mapping operation derived from cognitive theories of human reasoning. We show that without any direct training, visiPAM outperforms a state-of-the-art deep learning model on an analogical mapping task. In addition, visiPAM closely matches the pattern of human performance on a novel task involving mapping of 3D objects across disparate categories.

3.
Cogn Sci ; 47(9): e13347, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37718474

RESUMO

Advances in artificial intelligence have raised a basic question about human intelligence: Is human reasoning best emulated by applying task-specific knowledge acquired from a wealth of prior experience, or is it based on the domain-general manipulation and comparison of mental representations? We address this question for the case of visual analogical reasoning. Using realistic images of familiar three-dimensional objects (cars and their parts), we systematically manipulated viewpoints, part relations, and entity properties in visual analogy problems. We compared human performance to that of two recent deep learning models (Siamese Network and Relation Network) that were directly trained to solve these problems and to apply their task-specific knowledge to analogical reasoning. We also developed a new model using part-based comparison (PCM) by applying a domain-general mapping procedure to learned representations of cars and their component parts. Across four-term analogies (Experiment 1) and open-ended analogies (Experiment 2), the domain-general PCM model, but not the task-specific deep learning models, generated performance similar in key aspects to that of human reasoners. These findings provide evidence that human-like analogical reasoning is unlikely to be achieved by applying deep learning with big data to a specific type of analogy problem. Rather, humans do (and machines might) achieve analogical reasoning by learning representations that encode structural information useful for multiple tasks, coupled with efficient computation of relational similarity.


Assuntos
Inteligência Artificial , Inteligência , Humanos , Conhecimento , Resolução de Problemas
4.
Artigo em Inglês | MEDLINE | ID: mdl-35865343

RESUMO

Objective: To assess Interlukin-11 (IL11) expression in the tears of patients after filtration surgery and to find out its pro-transdifferentiational and pro-fibrotic functions and mechanisms on subconjunctival human Tenon's capsule fibroblasts (HTFs) induced by transforming growth factor beta1 (TGF-ß1). Methods: Tears were collected from glaucoma patients with or without filtration surgery. The expression of IL11 in tears was examined by enzyme-linked immunosorbent assay. Primary HTFs were prepared as an expansion culture of human Tenon's explants from patients undergoing cataract surgery. TGF-ß1 and IL11 were used to stimulate the cultured HTFs. Quantitative RT-PCR and western blot analyzed the roles of TGF-ß1 in IL11 and DNA methyltransferase (DNMT) expression and the effects of IL11 on collagen-1A1 and α-smooth muscle actin expression. The effects of IL11 on human HTFs' migration were tested via the scratch-wound assay. MassARRAY platform of Sequenom was applied for analyzing the quantitative methylation of the IL11 promoter region. Result: Our data presented significantly high levels of IL11 in the tears of patients who underwent filtration surgery with uncontrolled intraocular pressure (IOP) compared with those who underwent filtration surgery with controlled IOP. The up-regulation of IL11 was related to TGF-ß1. We also found that TGF-ß induced IL11 up-regulation in the HTFs, which activates the HTFs and enhanced the translation of the pro-fibrotic protein expression. This is correlated with inhibiting the activity and expression of DNMTs and demethylating the IL11 promoter. Therefore, IL11 may be an ideal target to be regulated to control the filtering pathway scar formation.

5.
Radiol Artif Intell ; 2(6): e190220, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33330848

RESUMO

PURPOSE: To evaluate the feasibility of a multiscale deep learning algorithm for quantitative visualization and measurement of traumatic hemoperitoneum and to compare diagnostic performance for relevant outcomes with categorical estimation. MATERIALS AND METHODS: This retrospective, single-institution study included 130 patients (mean age, 38 years; interquartile range, 25-50 years; 79 men) with traumatic hemoperitoneum who underwent CT of the abdomen and pelvis at trauma admission between January 2016 and April 2019. Labeled cases were separated into five combinations of training (80%) and test (20%) sets, and fivefold cross-validation was performed. Dice similarity coefficients (DSCs) were compared with those from a three-dimensional (3D) U-Net and a coarse-to-fine deep learning method. Areas under the receiver operating characteristic curve (AUCs) for a composite outcome, including hemostatic intervention, transfusion, and in-hospital mortality, were compared with consensus categorical assessment by two radiologists. An optimal cutoff was derived by using a radial basis function-based support vector machine. RESULTS: Mean DSC for the multiscale algorithm was 0.61 ± 0.15 (standard deviation) compared with 0.32 ± 0.16 for the 3D U-Net method and 0.52 ± 0.17 for the coarse-to-fine method (P < .0001). Correlation and agreement between automated and manual volumes were excellent (Pearson r = 0.97, intraclass correlation coefficient = 0.93). The algorithm produced intuitive and explainable visual results. AUCs for automated volume measurement and categorical estimation were 0.86 and 0.77, respectively (P = .004). An optimal cutoff of 278.9 mL yielded accuracy of 84%, sensitivity of 82%, specificity of 93%, positive predictive value of 86%, and negative predictive value of 83%. CONCLUSION: A multiscale deep learning method for traumatic hemoperitoneum quantitative visualization had improved diagnostic performance for predicting hemorrhage-control interventions and mortality compared with subjective volume estimation. Supplemental material is available for this article. © RSNA, 2020.

6.
Alzheimers Dement (Amst) ; 11: 405-414, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31206006

RESUMO

INTRODUCTION: The aim of this study was to investigate retinal thickness as a biomarker for identifying patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). METHODS: The retinal thickness, utilizing the spectral domain optical coherence tomography, was compared among 73 patients with AD, 51 patients with MCI, 67 cognitive normal control (NC) subjects. RESULTS: The retinal thickness of ganglion cell complex and peripapillary retinal nerve fiber layer decreased in both AD and MCI patients, in comparison with NC subjects (AD vs. NC, P < .01; MCI vs. NC, P < .01). The inner retinal layers in macular area in MCI exhibited significant thinning compared with NC (P < .001). Remarkable association was found between the retinal thickness and brain volume (P < .05). Better correlation was seen between the inner perifovea retinal thickness and the hippocampal and entorhinal cortex volume (r: 0.427-0.644, P < .01). DISCUSSION: The retinal thickness, especially the inner retinal layer thickness, is a potentially early AD marker indicating neurodegeneration.

7.
Exp Ther Med ; 15(1): 210-216, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29250149

RESUMO

Primary open-angle glaucoma (POAG) with complex pathogenesis is one of the many major causes of blindness. It is widely accepted that the major cause of POAG is the dysregulation of the trabecular meshwork (TM), which regulates the resistance to aqueous humour outflow. Intraocular pressure is elevated with increasing outflow resistance in the conventional pathway, which consists of the TM and Schlemm's canal. The TM is a filter made up of extracellular matrix (e.g., collagens), most of which is organized into a network of beams covered by endothelial-like trabecular cells. Currently, lack of effective anti-glaucoma drugs acting on TM to normalize trabecular outflow represents a bottleneck for POAG therapy. Atorvastatin, a lipid-lowering drug, has been proven to be of benefit for POAG. The present study aimed to investigate the possible mechanisms of action of atorvastatin on the TM by using a porcine aqueous humour outflow model in vivo and TM cells in vitro. Perfusion of enucleated porcine eyes with atorvastatin (50-200 µM) for 2 h increased aqueous humour outflow (P<0.05, n=6), possibly via regulating the morphology of TM cells and the distribution of the cytoskeleton. Atorvastatin decreased adhesion molecules at the mRNA and protein level. No cytotoxicity of atorvastatin on TM cells was observed at concentrations of <100 µM. The atorvastatin-induced effects mentioned above were reversible after removal of the compound only if the atorvastatin concentration was <100 µM. The present study demonstrated that atorvastatin efficaciously elevated aqueous humour outflow, possibly due to affecting TM-cell morphology, cytoskeleton and cell junctions. Statins may be potential therapeutic agents for lowering intraocular pressure in POAG.

8.
Invest Ophthalmol Vis Sci ; 58(14): 6123-6132, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29214311

RESUMO

Purpose: The purpose of this study was to evaluate the inhibitory mechanism of fingolimod and the involvement of sphingosine-1-phosphate receptors (S1PRs) and cytokines-matrix metalloproteinases (MMPs)/MAP kinases (MAPKs) signaling in a dry eye disease (DED) mouse model. Methods: Sixty-four male NOD mice (DED model) and 16 age-matched BALB/c mice were used. In a preliminary experiment, 16 NOD mice were randomly divided into a positive control group and fingolimod-treated groups, with 8 BALB/c mice serving as wild-type control. In a subsequent, separate study, 48 NOD mice were randomly divided into 6 groups: fingolimod-treated groups at three different concentrations (0.05%, 0.005%, and 0.001%), normal saline group, untreated group, and fingolimod+W146 group. Animals received normal saline or fingolimod eyedrops three times daily until euthanasia 2 months later. Mice in the fingolimod+W146 group received daily intraperitoneal injections of W146 (0.1 mg/kg/day). Proinflammatory mediators were assessed by a protein array. Activities of MMP-2 and MMP-9 were evaluated by zymography. MAPKs and S1PRs were examined by Western blots and immunohistochemistry. Infiltrating cells and inhibitory mechanisms were assessed. Results: In the positive control group, levels of inflammatory mediators and S1PRs were upregulated. By comparison, fingolimod treatment significantly suppressed such markers which were significantly reversed by W146 (P < 0.01). Importantly, by double immunofluorescence staining, leukocytes were confirmed involved in DED in the NOD mouse model. Conclusions: Leukocytes are involved in DED in the NOD mouse model. The therapeutic mechanisms of fingolimod may be associated with inhibitory roles of "cytokines-MMPs/MAPKs" cycle in NOD mouse ocular surface tissues by mediating S1PRs in infiltrating leukocytes.


Assuntos
Síndromes do Olho Seco/tratamento farmacológico , Cloridrato de Fingolimode/farmacologia , Leucócitos/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/patologia , Imuno-Histoquímica , Imunossupressores/farmacologia , Leucócitos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Esfingosina
9.
Invest Ophthalmol Vis Sci ; 58(3): 1478-1486, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28273314

RESUMO

Purpose: To examine the effects of losartan on scar formation after trabeculectomy and on fibrotic changes of human Tenon's fibroblasts (HTFs). Methods: Trabeculectomy was performed on New Zealand rabbits. They were randomized to receive one of the following treatments: 0.9% normal saline, mitomycin-C, or one of the three doses of losartan. Bleb morphology, IOP, and histopathology examination were performed. Primary cultured HTFs were treated with losartan or vehicle, with or without angiotensin II (Ang II). Cell proliferation was assessed by Cell Counting Kit-8 assay, and cell migration was detected by scratch wound and transwell assay. Transdifferentiation was evaluated through the expression of α-smooth muscle actin (α-SMA) by immunofluorescence, real-time PCR, and Western blot. The expression of fibronectin (FN) was evaluated by real-time PCR and Western blot. Results: An amount of 5 mg/mL of losartan subconjunctival injection significantly decreased IOP postoperatively and attenuated wound healing of the filtering bleb in the rabbit model. Immunostaining results showed less myofibroblast and collagen deposition around the bleb area in the losartan-treated eyes. Losartan (10-5 M) in vitro significantly attenuated Ang II's stimulatory effects on proliferation and migration of HTFs. Expressions of α-SMA and FN in these cells were also decreased by losartan pretreatment. Conclusions: Losartan attenuates scar formation of filtering bleb after trabeculectomy likely via decreasing proliferation, migration, transdifferentiation, and extracellular matrix deposition of Tenon's fibroblasts. These results indicate that losartan may be an effective therapeutic agent in preventing bleb scar formation and in improving surgical outcome after trabeculectomy.


Assuntos
Cicatriz/tratamento farmacológico , Glaucoma/cirurgia , Losartan/administração & dosagem , Complicações Pós-Operatórias/tratamento farmacológico , Trabeculectomia/efeitos adversos , Actinas/genética , Actinas/metabolismo , Idoso , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Animais , Western Blotting , Movimento Celular , Proliferação de Células , Células Cultivadas , Cicatriz/diagnóstico , Cicatriz/etiologia , Modelos Animais de Doenças , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Regulação da Expressão Gênica , Glaucoma/patologia , Glaucoma/fisiopatologia , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , RNA/genética , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Cápsula de Tenon/metabolismo , Cápsula de Tenon/patologia
10.
Curr Eye Res ; 42(7): 1018-1028, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28632033

RESUMO

PURPOSE: To investigate the involvement of activin receptor-like kinase 5 (ALK5) in human Tenon's capsule fibroblasts (HTFs) transdifferentiation and fibrosis. METHODS: (1) Cultured HTFs were treated with transforming growth factor beta 1 (TGF-ß1) at different concentrations for different durations, mRNA expression of ALK5 and plasminogen activator inhibitor-1 (PAI-1) was measured by quantitative polymerase chain reaction (PCR) while protein expression of ALK5, α-smooth muscle actin (α-SMA), and extracellular matrix deposition including fibronectin (FN) and collagen I (Col1) was assessed by western blot. HTFs with or without TGF-ß1 were also treated with an ALK5 activity inhibitor, SB-431542, and fibrosis-related genes were assessed. (2) HTFs were transduced with ALK5 lentivirus (ALK5-OE group) or empty lentivirus (NC-OE) with or without the treatment of SB-431542. Protein expression of ALK5, α-SMA, FN, and Col1 was evaluated. (3) HTFs in the ALK5-OE group and NC-OE group were subjected to a scratch-wound assay and their migratory activities assessed. RESULTS: (1) TGF-ß1, in a concentration-dependent manner, upregulated ALK5 and PAI-1 expressions in the HTFs, which peaked between 24 and 36 h. These changes were associated with increases in protein levels of FN, Col1, and α-SMA. These TGF-ß1 effects were blocked by the ALK5 inhibitor SB-431542. (2) Similarly, overexpression of ALK5 by lentiviral vector significantly increased protein expression of α-SMA, FN, and Col1. Addition of TGF-ß1 to the ALK5-OE cells did not produce additional expression of any of the marker proteins. The upregulation of extracellular matrix and α-SMA can be reduced by SB-431542. (3) In ALK5-OE group, HTFs migration was significantly increased compared with normal control and TGF-ß1 could still promote ALK5-OE cells migration. CONCLUSIONS: Our findings suggest that ALK5 is an important mediator of HTFs fibrosis. ALK5 is a potential therapeutic target to suppress scar formation after filtration surgery.


Assuntos
Fibroblastos/patologia , Regulação da Expressão Gênica , Glaucoma/genética , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Cápsula de Tenon/patologia , Adulto , Western Blotting , Transdiferenciação Celular , Células Cultivadas , Fibroblastos/metabolismo , Fibrose/genética , Fibrose/metabolismo , Fibrose/patologia , Glaucoma/metabolismo , Glaucoma/patologia , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/biossíntese , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Cápsula de Tenon/metabolismo
11.
Invest Ophthalmol Vis Sci ; 56(2): 855-64, 2015 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-25564450

RESUMO

PURPOSE: To examine the expression of Angiotensin II (Ang II) and its type I, and type II receptors (AT1R, AT2R) in rabbit Tenon's capsule fibroblasts after trabeculectomy, and to investigate the effects of Ang II on cultured human Tenon's capsule fibroblasts (HTFs) proliferation, migration, phenotype transition, and extracellular matrix (ECM) synthesis. METHODS: In the rabbit, expression of Ang II, AT1R, and AT2R in Tenon's capsule fibroblasts of eyes after trabeculectomy was evaluated by immunohistochemistry. Ang II levels in aqueous humor and plasma were assessed by ELISA. Cultured HTFs, obtained from patients undergoing cataract surgery, were treated with Ang II, TGF-ß1, or vehicle control. Cell proliferation and migration were evaluated by Cell Counting Kit-8 and Transwell assay, and wound scratch assay, respectively. Protein expressions of α-smooth muscle actin (α-SMA) and fibronectin (FN) were measured by Western blot and immunofluorescence. Messenger RNA expressions of α-SMA and FN were measured by real-time PCR. RESULTS: In the rabbit, the expression of Ang II and AT1R increased from 1 day after surgery while AT2R increased from 7 days. In cultured HTFs, Ang II promoted cell proliferation and migration significantly (P < 0.05). Interestingly, the effect of 10(-7) M Ang II was more prominent than higher concentrations (10(-5) M; P < 0.05). Ang II also markedly induced the expression of α-SMA and FN, suggesting a phenotypic transition to myofibroblasts. CONCLUSIONS: Our results show that trabeculectomy alter the levels of Ang II and its receptors in Tenon's capsule fibroblasts, and that Ang II increase HTFs proliferation, migration, and phenotype transition, suggesting that Ang II may play a role in wound healing after trabeculectomy.


Assuntos
Angiotensina II/genética , Regulação da Expressão Gênica , Glaucoma/genética , RNA Mensageiro/genética , Cápsula de Tenon/metabolismo , Cicatrização , Angiotensina II/biossíntese , Animais , Humor Aquoso/metabolismo , Western Blotting , Movimento Celular , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Fibroblastos/metabolismo , Fibroblastos/patologia , Glaucoma/metabolismo , Glaucoma/cirurgia , Imuno-Histoquímica , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Cápsula de Tenon/patologia , Trabeculectomia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa