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1.
Int J Mol Sci ; 22(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502323

RESUMO

The aim of the study was the multi-elemental analysis of aqueous humor (AH) collected from patients undergoing cataract surgery. The study included: 16 patients with age-related macular degeneration AMD (99 controls), 10 patients with retinopathy (105 controls), 61 patients with hypertension (54 controls), and 33 patients with coexisting diabetes (82 controls). The control groups were recruited from patients with a lack of co-existing disease characterizing the specified studied group. The measurements were performed by the use of inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was carried out using non-parametric testing (Mann-Whitney U). The level of significance was set at p = 0.05. The data obtained revealed substantial variations in elemental composition between the test groups in comparison to the controls. However, the significant variations concerned only a few elements. The phosphorous (P) level and the ratio of P/Ca were significant in retinopathy and diabetes, whereas cobalt (0.091 ± 0.107 mg/L vs. 0.031 ± 0.075 mg/L; p = 0.004) was significant in AMD. In co-existing hypertension, the levels of tin (0.293 ± 0.409 mg/L vs. 0.152 ± 0.3 mg/L; p = 0.031), titanium (0.096 ± 0.059 mg/L vs. 0.152 ± 0.192 mg/L; p = 0.045), and ruthenium (0.035 ± 0.109 mg/L vs. 0.002 ± 0.007 mg/L; p = 0.006) varied in comparison to the controls. The study revealed inter-elemental interactions. The correlation matrices demonstrated the domination of the positive correlations, whereas negative correlations mainly concerned sodium.


Assuntos
Humor Aquoso/metabolismo , Catarata/metabolismo , Diabetes Mellitus/fisiopatologia , Retinopatia Diabética/fisiopatologia , Elementos Químicos , Hipertensão/fisiopatologia , Degeneração Macular/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Catarata/epidemiologia , Catarata/patologia , Catarata/terapia , Extração de Catarata , Feminino , Seguimentos , Humanos , Cristalino/cirurgia , Masculino , Pessoa de Meia-Idade , Polônia/epidemiologia , Prognóstico
2.
Sci Rep ; 11(1): 17401, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465795

RESUMO

Cataracts, named for pathological light scattering in the lens, are known to be associated with increased large protein aggregates, disrupted protein phase separation, and/or osmotic imbalances in lens cells. We have applied synchrotron phase contrast X-ray micro-computed tomography to directly examine an age-related nuclear cataract model in Cx46 knockout (Cx46KO) mice. High-resolution 3D X-ray tomographic images reveal amorphous spots and strip-like dense matter precipitates in lens cores of all examined Cx46KO mice at different ages. The precipitates are predominantly accumulated in the anterior suture regions of lens cores, and they become longer and dense as mice age. Alizarin red staining data confirms the presence of calcium precipitates in lens cores of all Cx46KO mice. This study indicates that the spatial and temporal calcium precipitation is an age-related event associated with age-related nuclear cataract formation in Cx46KO mice, and further suggests that the loss of Cx46 promotes calcium precipitates in the lens core, which is a new mechanism that likely contributes to the pathological light scattering in this age-related cataract model.


Assuntos
Cálcio/metabolismo , Catarata/metabolismo , Animais , Catarata/patologia , Cristalino/metabolismo , Camundongos , Camundongos Knockout , Microtomografia por Raio-X
3.
Biomolecules ; 11(8)2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34439816

RESUMO

Cataracts are a leading cause of blindness worldwide. Surgical removal of cataracts is a safe and effective procedure to restore vision. However, a large number of patients later develop vision loss due to regrowth of lens cells and subsequent degradation of the visual axis leading to visual disability. This postsurgical complication, known as posterior capsular opacification (PCO), occurs in up to 30% of cataract patients and has no clinically proven pharmacological means of prevention. Despite the availability of many compounds capable of preventing early steps in PCO development, there is currently no effective means to deliver such therapies into the eye for a suitable duration. To model a solution to this unmet medical need, we fabricated acrylic substrates as intraocular lens (IOL) mimics scaled to place into the capsular bag of the mouse lens following a mock-cataract surgery. Substrates were coated with a hydrophilic crosslinked acrylate nanogel designed to elute Sorbinil, an aldose reductase inhibitor previously shown to suppress PCO. Insertion of the Sorbinil-eluting device into the lens capsule at the time of cataract surgery resulted in substantial prevention of cellular changes associated with PCO development. This model demonstrates that a cataract inhibitor can be delivered into the postsurgical lens capsule at therapeutic levels.


Assuntos
Opacificação da Cápsula/prevenção & controle , Extração de Catarata/efeitos adversos , Portadores de Fármacos , Inibidores Enzimáticos/farmacologia , Imidazolidinas/farmacologia , Lentes Intraoculares , Actinas/genética , Actinas/metabolismo , Animais , Caderinas/genética , Caderinas/metabolismo , Opacificação da Cápsula/etiologia , Opacificação da Cápsula/genética , Opacificação da Cápsula/patologia , Catarata/genética , Catarata/metabolismo , Catarata/patologia , Extração de Catarata/métodos , Modelos Animais de Doenças , Fibronectinas/genética , Fibronectinas/metabolismo , Regulação da Expressão Gênica , Humanos , Cristalino/metabolismo , Cristalino/patologia , Cristalino/cirurgia , Camundongos , Nanogéis/administração & dosagem , Nanogéis/química , Transdução de Sinais , Vimentina/genética , Vimentina/metabolismo
4.
Aging (Albany NY) ; 13(13): 17568-17591, 2021 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-34226295

RESUMO

The homeostasis of the ocular lens is maintained by a microcirculation system propagated through gap junction channels. It is well established that the intercellular communications of the lens become deteriorative during aging. However, the molecular basis for this change in human lenses has not been well defined. Here, we present evidence to show that over 90% of Cx46 and Cx50 are lost in the fiber cells of normal human lenses aged 50 and above. From transparent to cataractous lenses, while Cx43 was upregulated, both Cx46 and Cx50 were significantly down-regulated in the lens epithelia. During aging of mouse lenses, Cx43 remained unchanged, but both Cx46 and Cx50 were significantly downregulated. Under oxidative stress treatment, mouse lenses develop in vitro cataractogenesis. Associated with this process, Cx43 was significantly upregulated, in contrast, Cx46 and Cx50 were sharply downregulated. Together, our results for the first time reveal that downregulation in Cx46 and Cx50 levels appears to be the major reason for the diminished coupling conductance, and the aging-dependent loss of Cx46 and Cx50 promotes senile cataractogenesis.


Assuntos
Envelhecimento/fisiologia , Catarata/genética , Catarata/patologia , Conexinas/biossíntese , Conexinas/genética , Cristalino/patologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Epitélio Corneano/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade
5.
Exp Eye Res ; 210: 108697, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34233175

RESUMO

Hyperbaric oxygen (HBO) treatment of animals or ocular lenses in culture recapitulates many molecular changes observed in human age-related nuclear cataract. The guinea pig HBO model has been one of the best examples of such treatment leading to dose-dependent development of lens nuclear opacities. In this study, complimentary mass spectrometry methods were employed to examine protein truncation after HBO treatment of aged guinea pigs. Quantitative liquid chromatography-mass spectrometry (LC-MS) analysis of the membrane fraction of guinea pig lenses showed statistically significant increases in aquaporin-0 (AQP0) C-terminal truncation, consistent with previous reports of accelerated loss of membrane and cytoskeletal proteins. In addition, imaging mass spectrometry (IMS) analysis spatially mapped the acceleration of age-related αA-crystallin truncation in the lens nucleus. The truncation sites in αA-crystallin closely match those observed in human lenses with age. Taken together, our results suggest that HBO accelerates the normal lens aging process and leads to nuclear cataract.


Assuntos
Envelhecimento/fisiologia , Catarata/etiologia , Cristalinas/metabolismo , Oxigenação Hiperbárica/efeitos adversos , Núcleo do Cristalino/metabolismo , Proteólise/efeitos dos fármacos , Animais , Aquaporinas/metabolismo , Catarata/metabolismo , Catarata/patologia , Cromatografia Líquida , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Proteínas do Olho/metabolismo , Cobaias , Núcleo do Cristalino/patologia , Espectrometria de Massas em Tandem , Cadeia A de alfa-Cristalina/metabolismo
6.
Exp Eye Res ; 210: 108704, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34302851

RESUMO

Advanced glycation end products (AGEs) accumulate with age in human lens capsules. AGEs in lens capsules potentiate the transforming growth factor beta-2-mediated mesenchymal transition of lens epithelial cells, which suggests that they play a role in posterior capsule opacification after cataract surgery. We measured AGEs by liquid chromatography-mass spectrometry in capsulorhexis specimens obtained during cataract surgery from nondiabetic and diabetic patients with and without established retinopathy. Our data showed that the levels of most AGEs (12 out of 13 measured) were unaltered in diabetic patients and diabetic patients with retinopathy compared to nondiabetic patients. There was one exception: glucosepane, which was significantly higher in diabetic patients, both with (6.85 pmol/µmol OH-proline) and without retinopathy (8.32 pmol/µmol OH-proline), than in nondiabetic patients (4.01 pmol/µmol OH-proline). Our study provides an explanation for the similar incidence of posterior capsule opacification between nondiabetic and diabetic cataract patients observed in several studies.


Assuntos
Catarata/metabolismo , Retinopatia Diabética/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Cápsula do Cristalino/metabolismo , Idoso , Glicemia/metabolismo , Capsulorrexe , Catarata/patologia , Cromatografia Líquida , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Retinopatia Diabética/patologia , Feminino , Hemoglobina A Glicada/metabolismo , Humanos , Cápsula do Cristalino/patologia , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem
7.
Sci Rep ; 11(1): 13771, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215815

RESUMO

Autophagy is a degradation process of cytoplasmic proteins and organelles trafficked to degradation vesicles known as autophagosomes. The conversion of LC3-I to LC3-II is an essential step of autophagosome formation, and FYCO1 is a LC3-binding protein that mediates autophagosome transport. The p62 protein also directly binds to LC3 and is degraded by autophagy. In the present study, we demonstrated that disrupting the FYCO1 gene in mice resulted in cataract formation. LC3 conversion decreased in eyes from FYCO1 knockout mice. Further, FYCO1 interacted with αA- and αB-crystallin, as demonstrated by yeast two-hybrid screening and immunoprecipitation analyses. In eyes from knockout mice, the soluble forms of αA- and αB-crystallin, the lens's major protein components, decreased. In addition, p62 accumulated in eyes from FYCO1 knockout mice. Collectively, these findings suggested that FYCO1 recruited damaged α-crystallin into autophagosomes to protect lens cells from cataract formation.


Assuntos
Autofagia/genética , Catarata/genética , Proteínas Associadas aos Microtúbulos/genética , Proteína Sequestossoma-1/genética , Animais , Autofagossomos/genética , Catarata/patologia , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Knockout , Cadeia A de alfa-Cristalina/genética , Cadeia B de alfa-Cristalina/genética
8.
Aging (Albany NY) ; 13(11): 15255-15268, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34096886

RESUMO

Cataract is the leading cause of visual impairment globally. Racemization of lens proteins may contribute to cataract formation in aging individuals. As a special type of age-related cataract (ARC), diabetic cataract (DC) is characterized by the early onset of cortical opacification and finally developed into a mixed type of cortical and nuclear opacification. We compared racemization of Asp 58 residue, a hotspot position in αA-crystallin, from the cortex and nucleus of diabetic and age-matched senile cataractous lenses, by identifying L-Asp/L-isoAsp/D-Asp/D-isoAsp by mass spectrometry. Compared to nondiabetic cataractous lenses, DC lenses showed a significantly increased cortex/nucleus ratio of D-Asp 58, which originated primarily from an increased percentage of D-Asp 58 in the lens cortex of DC. Moreover, patients diagnosed with diabetes for over 10 years showed a lower cortex/nucleus ratio of D-isoAsp 58 in the lens compared with those who had a shorter duration of diabetes, which originated mainly from an increased percentage of D-isoAsp 58 in the lens nucleus of DC with increasing time of hyperglycemia. Further analysis confirmed decreased protein solubility in diabetic cataractous lenses. The different racemization pattern in DC may be distinguished from ARC and influence its phenotype over the protracted duration of diabetes.


Assuntos
Ácido Aspártico/metabolismo , Catarata/patologia , Cristalinas/química , Cristalino/patologia , Idoso , Envelhecimento/patologia , Núcleo Celular/metabolismo , Feminino , Humanos , Isomerismo , Masculino , Solubilidade
9.
Genes (Basel) ; 12(5)2021 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-34065151

RESUMO

BACKGROUND: Congenital aniridia is a complex ocular disorder, usually associated with severe visual impairment, generally caused by mutations on the PAX6 gene. The clinical phenotype of PAX6 mutations is highly variable, making the genotype-phenotype correlations difficult to establish. METHODS: we describe the phenotype of eight patients from seven unrelated families with confirmed mutations in PAX6, and very different clinical manifestations. RESULTS: Only two patients had the classical aniridia phenotype while the other two presented with aniridia-related manifestations, such as aniridia-related keratopathy or partial aniridia. Congenital cataracts were the main manifestation in three of the patients in this series. All the patients had nystagmus and low visual acuity. CONCLUSIONS: The diagnosis of mild forms of aniridia is challenging, but these patients have a potentially blinding hereditary disease that might present with a more severe phenotype in future generations. Clinicians should be aware of the mild aniridia phenotype and request genetic testing to perform an accurate diagnosis.


Assuntos
Aniridia/genética , Catarata/genética , Distrofias Hereditárias da Córnea/genética , Nistagmo Congênito/genética , Fator de Transcrição PAX6/genética , Fenótipo , Adolescente , Adulto , Aniridia/patologia , Catarata/patologia , Criança , Distrofias Hereditárias da Córnea/patologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Nistagmo Congênito/patologia
10.
J Photochem Photobiol B ; 221: 112248, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34192628

RESUMO

Melatonin is mainly secreted by the pineal gland, and it is also produced by various ocular structures such as the lens. It has been recently demonstrated that melatonin ocular synthesis can be induced by blocking the blue component of white light by means of filters. Melatonin exhibits antioxidant properties that can be useful to face light-induced oxidative stress as well as oxidative events associated to ocular pathologies like cataracts. Moreover, as oxidative stress is a main event in cataract development, changes in melatonin levels could happen and be relevant in the progression of this pathology, a subject that remains uncertain. The goal of this work was to analyze the ability of a short wavelength light blocking (yellow) filter to modulate endogenous melatonin concentration and the antioxidant and cytoprotective actions induced by yellow filter's use in lens. Furthermore, we evaluated the potential changes in aqueous humor melatonin concentration from patients with cataracts. In human lens epithelial cells, white light-emitting diode (LED) light challenge reduced melatonin secretion, protein levels of the enzymes involved in melatonin synthesis (hydroxyindole-O-methyltransferase and unphosphorylated and phosphorylated forms of arylalkylamine N-acetyltransferase) and cell viability whereas increased reactive oxygen species production. Yellow filter exposure precluded melatonin secretion reduction and protected cells from oxidative damage. Consistent with cataract patient's results, significantly lower levels of melatonin were observed in aqueous humor of alloxan-induced diabetic cataract rabbits as compared to those of control rabbits. In contrast, aqueous humor melatonin levels of diabetic cataract animals maintaining in cages covered with a yellow filter resembled control values. This recovery seems to be mediated by the induction of melatonin biosynthetic enzymes protein expression. Yellow filter also preserved Nrf2 lens protein expression and superoxide dismutase protein levels and activity in diabetic animals. Modulation of endogenous ocular melatonin concentration using blocking filters might be a promising approach to prevent premature lens opacification.


Assuntos
Humor Aquoso/metabolismo , Melatonina/metabolismo , Substâncias Protetoras/metabolismo , Idoso , Animais , Catarata/metabolismo , Catarata/patologia , Sobrevivência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/efeitos da radiação , Feminino , Humanos , Cristalino/citologia , Luz , Masculino , Melatonina/farmacologia , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Coelhos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para Cima/efeitos dos fármacos
11.
Sci Rep ; 11(1): 12685, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135449

RESUMO

The aim of this study is to investigate the impact of age-related lens opacities and advanced cataract, quantified by LOCS III grading, on quantitative autofluorescence (qAF) measurements in patients before and after cataract surgery. Images from a randomized controlled trial evaluating the impact of femtosecond-laser assisted cataract surgery (FLACS) on retinal thickness were analyzed post-hoc. One-hundred and twenty eyes from 60 consecutive patients with age-related cataract were included and assessed with qAF and optical coherence tomography (OCT) before, 1, 3 and 6 weeks after cataract surgery (randomized 1:1 to FLACS or phacoemulsification). LOCS III grading was performed before surgery. Pre- to post-surgical qAF values, as well as the impact of LOCS III gradings, surgery technique, gender, axial length and age on post-surgery qAF values was investigated using generalized linear mixed models. For this analysis, 106 eyes from 53 patients were usable. No difference in qAF was found between FLACS and phacoemulsification (p > 0.05) and results were pooled for the total cohort. Mean pre-surgical qAF was 89.45 ± 44.9 qAF units, with a significant mean increase of 178.4-191.6% after surgery (p < 0.001). No significant difference was found between the three follow-up visits after surgery (p > 0.05). Higher LOCS III cortical opacity quantifications were associated with a significantly greater increase in qAF after surgery (estimate: 98.56, p = 0.006) and nuclear opacities showed a trend toward an increased change (estimate: 48.8, p = 0.095). Considerable interactions were identified between baseline qAF and cortical opacities, nuclear opacities and posterior subcapsular opacities, as well as nuclear opacities and cortical opacities (p = 0.012, p = 0.064 and p = 0.069, respectively). Quantitative autofluorescence signals are significantly reconstituted after cataract surgery and LOCS III gradings are well associated with post-surgical qAF values. Careful consideration of age-related lens opacities is vital for the correct interpretation of qAF, especially in retinal diseases affecting the elderly.ClinicalTrials.gov Identifier: NCT03465124.


Assuntos
Extração de Catarata , Catarata/patologia , Cristalino/patologia , Imagem Óptica , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Facoemulsificação , Tomografia de Coerência Óptica
12.
Sci Rep ; 11(1): 11514, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075156

RESUMO

The aim of the study is to explore the distribution patterns and internal correlations of the morphological parameters of the cornea in patients with age-related cataract. The Pentacam HR was used to measure anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), total corneal astigmatism (TCA) and keratometric corneal astigmatism (KCA). With age, the proportion of with-the-rule (WTR) ACA decreased from 65.31% to 23.63%, while the against-the-rule (ATR) ACA increased from 26.53% to 56.20%. PCA exceeded 0.50 D in 9.14% of eyes, while 76.35% of them were ATR. The magnitude of ACA was positively correlated with PCA in the whole sample, with a more significant correlation in WTR eyes (sr = 0.349, P < 0.001). The vector summation effect of PCA to ACA changed from compensation to augmentation with aging. In 57.53% of WTR eyes, KCA was overestimated by an average of 0.21 ± 0.17 D, while it was underestimated by 0.38 ± 0.27 D in 87.62% of ATR eyes. In conclusion, among age-related cataract patients, ACA and TCA gradually shifted from WTR to ATR with aging, while most PCA remained as ATR. Ignoring the age-related changes and real PCA might cause overestimation of WTR astigmatism and underestimation of ATR astigmatism.


Assuntos
Envelhecimento/patologia , Astigmatismo , Catarata , Adulto , Idoso , Idoso de 80 Anos ou mais , Astigmatismo/etiologia , Astigmatismo/patologia , Astigmatismo/fisiopatologia , Catarata/complicações , Catarata/patologia , Catarata/fisiopatologia , Topografia da Córnea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
PLoS One ; 16(6): e0252640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086796

RESUMO

BACKGROUND: Transparent and complete publications of randomised controlled trials (RCT) ought to comply with the guidelines of the CONSORT Statement, which stipulates sample size calculation as an important aspect of trial planning. The objective of this study was to analyse and compare the reporting of statistical sample size calculations in RCT papers on the treatment of age-related macular degeneration (AMD), glaucoma and cataract published in 2018. MATERIAL AND METHODS: This study comprises a total of 113 RCT papers (RCT-P) published in 2018 (AMD: 14, glaucoma: 28, cataract: 71), in English or German, and identified through an internet-based literature search in PubMed and EMBASE. The primary outcome measure of the study was the number of trials providing a complete description of the underlying sample case calculation on the basis of the variables required (significance level, expected outcomes, power, and resulting sample size). RESULTS: Of the RCTs reviewed, 64% (AMD), 61% (glaucoma) and 31% (cataract) provided a justification of the number of patients included. A complete description of the described studies' sample size calculation including all the necessary values (primary outcome measure of this study) was described by 21% of the AMD, 29% of the cataract and 18% of the glaucoma RCT publications (in total: 24 of 113 (21%) at a confidence interval of 95%: [13%; 29%]). CONCLUSION: All three treatment areas analysed lacked reporting quality regarding the justification of the number of patients included in a clinical trial based on a sample size calculation required for ethical reasons. More than half of all RCT publications reviewed did not provide all of the required information on statistical sample size calculation, and thus lacked transparency and completeness. It is therefore urgently required to involve methodologists in a study's planning and publishing processes to ensure that methodology descriptions are transparent and of high quality.


Assuntos
Catarata/terapia , Glaucoma/terapia , Degeneração Macular/terapia , Editoração/estatística & dados numéricos , Tamanho da Amostra , Catarata/patologia , Bases de Dados Factuais , Glaucoma/patologia , Humanos , Modelos Logísticos , Degeneração Macular/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
FASEB J ; 35(6): e21593, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33991133

RESUMO

Diabetes is a major risk factor for cataract, the leading cause of blindness worldwide. There is an unmet need for a realistic model of diabetic cataract for mechanistic and longitudinal studies, as existing models do not reflect key aspects of the complex human disease. Here, we introduce and characterize diabetic cataract in the Nile grass rat (NGR, Arvicanthis niloticus), an established model of metabolic syndrome and type 2 diabetes (T2D). We conducted a longitudinal study of cataract in over 88 NGRs in their non-diabetic, pre-diabetic, and diabetic stages of metabolism. Oral glucose tolerance test (OGTT) results distinguished the metabolic stages. Diverse cataract types were observed in the course of diabetes, including cortical, posterior subcapsular (PSC), and anterior subcapsular (ASC), all of which succeeded a characteristic dotted ring stage in all animals. The onset ages of diabetes and cataract were 44 ± 3 vs 29 ± 1 (P < .001) and 66 ± 5 vs 58 ± 6 (not significant) weeks in females and males, respectively. Histological analysis revealed fiber disorganization, vacuolar structures, and cellular proliferation and migration in cataractous lenses. The lens epithelial cells (LECs) in non-diabetic young NGRs expressed the stress marker GRP78, as did LECs and migrated cells in the lenses of diabetic animals. Elucidating mechanisms underlying LEC proliferation and migration will be clinically valuable in prevention and treatment of posterior capsule opacification, a dreaded complication of cataract surgery. Marked changes in N-cadherin expression emphasized a role for LEC integrity in cataractogenesis. Apoptotic cells were dispersed in the equatorial areas in early cataractogenesis. Our study reveals diverse cataract types that spontaneously develop in the diabetic NGR, and which uniquely mirror the cataract and its chronic course of development in individuals with diabetes. We provide mechanistic insights into early stages of diabetic cataract. These unique characteristics make NGR highly suited for mechanistic studies, especially in the context of metabolism, diabetes, and aging.


Assuntos
Catarata/patologia , Complicações do Diabetes/patologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Células Epiteliais/patologia , Cristalino/patologia , Animais , Catarata/etiologia , Movimento Celular , Proliferação de Células , Complicações do Diabetes/etiologia , Feminino , Estudos Longitudinais , Masculino , Fenótipo , Ratos
15.
Chem Biol Interact ; 344: 109495, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33961834

RESUMO

Cataracts, a clouding of the eye lens, are a leading cause of visual impairment and are responsible for one of the most commonly performed surgical procedures worldwide. Although generally safe and effective, cataract surgery can lead to a secondary lens abnormality due to transition of lens epithelial cells to a mesenchymal phenotype (EMT) and opacification of the posterior lens capsular bag. Occurring in up to 40% of cataract cases over time, posterior capsule opacification (PCO) introduces additional treatment costs and reduced quality of life for patients. Studies have shown that PCO pathogenesis is driven in part by TGF-ß, signaling through the action of the family of Smad coactivators to effect changes in gene transcription. In the present study, we evaluated the ability of Smad-7, a well characterized inhibitor of TGF-ß -mediated Smad signaling, to suppress the EMT response in lens epithelial cells associated with PCO pathogenesis. Treatment of lens epithelial cells with a cell-permeable form of Smad7 variant resulted in suppressed expression of EMT markers such as alpha smooth muscle actin and fibronectin. A single application of cell-permeable Smad7 variant in the capsular bag of a mouse cataract surgery model resulted in suppression of gene transcripts encoding alpha smooth muscle actin and fibronectin. These results point to Smad7 as a promising biotherapeutic agent for prevention or substantial reduction in the incidence of PCO following cataract surgery.


Assuntos
Opacificação da Cápsula/prevenção & controle , Peptídeos Penetradores de Células/uso terapêutico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Produtos do Gene tat/uso terapêutico , Cristalino/efeitos dos fármacos , Proteína Smad7/uso terapêutico , Actinas/metabolismo , Animais , Opacificação da Cápsula/etiologia , Opacificação da Cápsula/patologia , Catarata/complicações , Catarata/patologia , Células Epiteliais/efeitos dos fármacos , Cristalino/patologia , Camundongos Transgênicos , Domínios Proteicos , Proteínas Recombinantes/uso terapêutico
16.
Biomolecules ; 11(4)2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807297

RESUMO

Cells encounter a myriad of endogenous and exogenous stresses that could perturb cellular physiological processes. Therefore, cells are equipped with several adaptive and stress-response machinery to overcome and survive these insults. One such machinery is the heat shock response (HSR) program that is governed by the heat shock factors (HSFs) family in response towards elevated temperature, free radicals, oxidants, and heavy metals. HSF4 is a member of this HSFs family that could exist in two predominant isoforms, either the transcriptional repressor HSFa or transcriptional activator HSF4b. HSF4 is constitutively active due to the lack of oligomerization negative regulator domain. HSF4 has been demonstrated to play roles in several physiological processes and not only limited to regulating the classical heat shock- or stress-responsive transcriptional programs. In this review, we will revisit and delineate the recent updates on HSF4 molecular properties. We also comprehensively discuss the roles of HSF4 in health and diseases, particularly in lens cell development, cataract formation, and cancer pathogenesis. Finally, we will posit the potential direction of HSF4 future research that could enhance our knowledge on HSF4 molecular networks as well as physiological and pathophysiological functions.


Assuntos
Catarata/patologia , Fatores de Transcrição de Choque Térmico/metabolismo , Neoplasias/patologia , Catarata/metabolismo , Diferenciação Celular , Fatores de Transcrição de Choque Térmico/classificação , Fatores de Transcrição de Choque Térmico/genética , Humanos , Cristalino/citologia , Cristalino/metabolismo , Neoplasias/metabolismo , Filogenia , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína
17.
J Biochem Mol Toxicol ; 35(7): e22789, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33847027

RESUMO

Previously, we established several facts regarding hypertension-associated cataractogenesis. As a follow-on study, we evaluated the role of the renin-angiotensin system (RAS) in angiotensin-II (Ang-II)-induced cataract formation in experimental hypertensive rats. Sprague-Dawley male albino rats (150-180 g) were used for the present experiment. The animals were divided into four groups, with six animals in each group. During the 12 weeks of the experimental protocol, the normal group received sterile water (1 ml/kg/day, subcutaneously (sc), and the Ang-II control group received angiotensin (1 mg/kg/day) subcutaneously. The ARB (O) group received olmesartan (2 mg/kg/day) orally, and the ARB (T) group received two drops of olmesartan (5 mM) topically on the cornea; concurrently, both groups were treated with Ang-II (1 mg/kg/day, sc) to induce hypertension. Biweekly, the systolic and the diastolic blood pressures were recorded, and the eyes were examined; moreover, cataractogenic parameters, such as oxidative stress markers and protein contents in the lenses, were evaluated after completion of the experimental protocol. Twelve weeks of olmesartan administered, orally or topically, significantly reduced the progression of cataract formation and restored antioxidants, lipid peroxidation, nitrite content, and protein contents in the lenses of the mice in groups O and T, respectively, as compared with those in the Ang-II control group. On the basis of our results, we conclude that the ocular RAS exacerbates the lenticular oxidative stress that may lead to cataract formation. The results showed that the RAS has an independent and important role in cataract formation under hypertensive conditions.


Assuntos
Angiotensina II/efeitos adversos , Catarata , Sistema Renina-Angiotensina/efeitos dos fármacos , Angiotensina II/farmacologia , Animais , Catarata/induzido quimicamente , Catarata/metabolismo , Catarata/patologia , Imidazóis/farmacologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Tetrazóis/farmacologia
18.
PLoS One ; 16(4): e0250277, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33857260

RESUMO

Post-translational modifications are often detected in age-related diseases associated with protein misfolding such as cataracts from aged lenses. One of the major post-translational modifications is the isomerization of aspartate residues (L-isoAsp), which could be non-enzymatically and spontaneously occurring in proteins, resulting in various effects on the structure and function of proteins including short peptides. We have reported that the structure and function of an αA66-80 peptide, corresponding to the 66-80 (66SDRDKFVIFLDVKHF80) fragment of human lens αA-crystallin, was dramatically altered by the isomerization of aspartate residue (Asp) at position 76. In the current study, we observed amyloid-like fibrils of L-isoAsp containing αA66-80 using electron microscopy. The contribution of each amino acid for the peptide structure was further evaluated by circular dichroism (CD), bis-ANS, and thioflavin T fluorescence using 14 alanine substituents of αA66-80, including L-isoAsp at position 76. CD of 14 alanine substituents demonstrated random coiled structures except for the substituents of positively charged residues. Bis-ANS fluorescence of peptide with substitution of hydrophobic residue with alanine revealed decreased hydrophobicity of the peptide. Thioflavin T fluorescence also showed that the hydrophobicity around Asp76 of the peptide is important for the formation of amyloid-like fibrils. One of the substitutes, H79A (SDRDKFVIFL(L-isoD)VKAF) demonstrated an exact ß-sheet structure in CD and highly increased Thioflavin T fluorescence. This phenomenon was inhibited by the addition of protein-L-isoaspartate O-methyltransferase (PIMT), which is an enzyme that changes L-isoAsp into Asp. These interactions were observed even after the formation of amyloid-like fibrils. Thus, isomerization of Asp in peptide is key to form fibrils of αA-crystallin-derived peptide, and L-isoAsp on fibrils can be a candidate for disassembling amyloid-like fibrils of αA-crystallin-derived peptides.


Assuntos
Amiloide/química , Ácido Aspártico/metabolismo , Ácido Isoaspártico/metabolismo , Processamento de Proteína Pós-Traducional , Cadeia A de alfa-Cristalina/metabolismo , Envelhecimento/genética , Alanina/química , Alanina/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Amiloide/genética , Amiloide/metabolismo , Ácido Aspártico/química , Benzotiazóis/química , Catarata/genética , Catarata/metabolismo , Catarata/patologia , Corantes Fluorescentes/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Ácido Isoaspártico/química , Isomerismo , Cristalino/metabolismo , Cristalino/patologia , Microscopia Eletrônica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/química , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/metabolismo , Eletricidade Estática , Cadeia A de alfa-Cristalina/genética
19.
Cells ; 10(4)2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918979

RESUMO

Decorin (DCN) is involved in a variety of physiological and pathological processes. Epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) has been proposed as a major cause for the development of posterior capsule opacification (PCO) after cataract surgery. We investigated the plausible target gene(s) that suppress PCO. The expression of Dcn was significantly upregulated in rat PCO tissues compared to that observed in the control using a microarray-based approach. LECs treated with fibroblast growth factor (FGF) 2 displayed an enhanced level of DCN expression, while LECs treated with transforming growth factor (TGF)ß-2 showed a decrease in DCN expression. The expression of tropomyosin 1 (Tpm1), a marker of lens EMT increased after the addition of TGFß-2 in human LEC; however, upregulation of Tpm1 mRNA or protein expression was reduced in human LECs overexpressing human DCN (hDCN). No phenotypic changes were observed in the lenses of 8- and 48-week-old transgenic mice for lens-specific hDCN (hDCN-Tg). Injury-induced EMT of the mouse lens, and the expression patterns of α smooth muscle actin, were attenuated in hDCN-Tg mice lenses. Overexpression of DCN inhibited the TGFß-2-induced upregulation of Tpm1 and EMT observed during wound healing of the lens, but it did not affect mouse lens morphology until 48 weeks of age. Our findings demonstrate that DCN plays a significant role in regulating EMT formation of LECs and PCO, and suggest that for therapeutic intervention, maintenance of physiological expression of DCN is essential to attenuate EMT progression and PCO formation.


Assuntos
Opacificação da Cápsula/metabolismo , Decorina/metabolismo , Cristalino/embriologia , Cristalino/metabolismo , Envelhecimento/patologia , Animais , Humor Aquoso/efeitos dos fármacos , Humor Aquoso/metabolismo , Catarata/genética , Catarata/patologia , Decorina/genética , Modelos Animais de Doenças , Regulação para Baixo/genética , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Perfilação da Expressão Gênica , Ontologia Genética , Humanos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Fator de Crescimento Transformador beta2/farmacologia , Tropomiosina/metabolismo , Regulação para Cima/genética , Cicatrização/efeitos dos fármacos
20.
Commun Biol ; 4(1): 325, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33707565

RESUMO

Congenital cataracts are associated with gene mutations, yet the underlying mechanism remains largely unknown. Here we reported an embryonic chick lens model that closely recapitulates the process of cataract formation. We adopted dominant-negative site mutations that cause congenital cataracts, connexin, Cx50E48K, aquaporin 0, AQP0R33C, αA-crystallin, CRYAA R12C and R54C. The recombinant retroviruses containing these mutants were microinjected into the occlusive lumen of chick lenses at early embryonic development. Cx50E48K expression developed cataracts associated with disorganized nuclei and enlarged extracellular spaces. Expression of AQP0R33C resulted in cortical cataracts, enlarged extracellular spaces and distorted fiber cell organization. αA crystallin mutations distorted lens light transmission and increased crystalline protein aggregation. Together, retroviral expression of congenital mutant genes in embryonic chick lenses closely mimics characteristics of human congenital cataracts. This model will provide an effective, reliable in vivo system to investigate the development and underlying mechanism of cataracts and other genetic diseases.


Assuntos
Aquaporinas/genética , Catarata/congênito , Conexinas/genética , Cristalinas/genética , Proteínas do Olho/genética , Cristalino/anormalidades , Mutação , Animais , Aquaporinas/metabolismo , Catarata/metabolismo , Catarata/patologia , Embrião de Galinha , Conexinas/metabolismo , Cristalinas/metabolismo , Modelos Animais de Doenças , Proteínas do Olho/metabolismo , Técnicas de Transferência de Genes , Predisposição Genética para Doença , Vetores Genéticos , Cristalino/metabolismo , Microinjeções , Fenótipo , Retroviridae/genética , Retroviridae/metabolismo
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