Current Eye Research最新文献

Purpose: To analyze the role of Slit2 in lens epithelial cell oxidative damage and its underlying mechanism.

Methods: Human lens epithelial cells (SRA01/04 cells) and rat transparent lens were cultured with H₂O₂ to establish cell oxidative stress models and rat cataract models. Immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot assays were employed to detect Slit2 levels within age-related cataracts(ARC) lens anterior capsule samples, rat cataract models, and cell oxidative stress models. In this study, qRT-PCR and Western blot assays were performed to derermine E-cadherin, N-cadherin, occludens1(ZO-1), α-SMA(α‑smooth muscle actin), Bcl-2, Bax, p-AKT, and AKT levels. In addition, Flow cytometry were performed to examine reactive oxygen species (ROS) and cell apoptosis. Cell viability, invasion, and migration were detected by CCK8, Transwell, and Wound healing.

Results: Increased expression of Slit2 was found in ARC lens anterior capsule samples, H₂O₂-induced rat cataract models, and Human lens epithelial cells (HLECs) oxidative stress models. H₂O₂ significantly increased cell apoptosis and ROS generation, also accelerating cell migration, invasion, and epithelial-mesenchymal transition (EMT). In addition, H₂O₂ treatment repressed AKT phosphorylation and cell viability. Knock-down of Slit2 promoted cell viability and AKT phosphorylation levels, as well as repressed cell invasion, migration, apoptosis, ROS production and EMT.

Conclusion: Slit2 promoted lens epithelial cells oxidative stress damage via the AKT signalling pathways, providing a novel insight in ARC treatment.

Purpose: Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered gold standard in the treatment of posterior capsule opacification (PCO). In this laboratory study, we measured spectral transmission to evaluate the image contrast and analyze the impact of Nd:YAG associated defects in presbyopia-correcting intraocular lenses (IOLs).

Methods: Two hydrophobic, acrylic IOLs as classic multifocal lenses with diffractive ring segments and different amount of near addition (A, B), one hydrophilic, trifocal IOL (C), one sector-shaped, plate haptic IOL (D) and one hydrophobic, enhanced depth of focus (EDOF) IOL (E) were studied. Measurements included surface topography characterization, United States Air Force resolution test chart (USAF) analysis, spectral transmittance measurements and through focus contrast measurement. Measurements were done with unaltered samples, damages (n = 7) were intentionally created in the central 3.5 mm zone using a photodisruption laser (2.0 mJ) and measurements were repeated.

Results: Significant differences were shown between unmodified samples and samples with YAG pits. The YAG-pits decreased the image contrast and spectral transmission and changed results of USAF test images. The imaging contrast decreased to 66%, 64%, 60%, 52% and 59% with the YAG shots in samples (A-E). The light transmission decreased to 88%, 87%, 92%, 79% and 91% (A-E) on average between 400 nm to 800 nm. In all IOLs a reduction of the relative intensity of transmitted light was observed.

Conclusion: The image performance of all tested presbyopia-correcting IOLs is significantly influenced and disturbed by YAG-pits. The intensity of transmitted light is reduced in the wavelength between 450-800 nm. USAF test targets show worse results compared to unmodified samples and contrast is significantly deteriorated. No ranking/rating among tested IOLs should be made as many other factors play a role in real world scenario. High care should be taken when performing Nd:YAG capsulotomy on premium IOLs to avoid any damages.

Purpose: To reveal changes in choroidal thickness, retinal vessel density, and serum HIF-1α and TNF-α levels in obstructive sleep apnea syndrome (OSAS) and their correlation.

Methods: This prospective case-control study included 118 patients divided into mild-to-moderate OSAS (n = 40), severe OSAS (n = 39), and a control group (n = 39). Choroidal thickness was evaluated with OCT, vessel density with OCTA, AHI index with polysomnography, and serum HIF-1α and TNF-α levels were analyzed using the enzyme-linked immunosorbent assay.

Results: The serum HIF-1α values of the participants in the mild-moderate OSAS and severe OSAS groups were [893.25(406.7-2068) and 1027(453-2527), respectively], and were both significantly higher than the control group [(521.5(231.6-2741))] (p < 0.001). Serum TNF-α levels did not differ significantly between the groups (p = 0.051).). Subfoveal choroidal thickness (SFCT) values of the severe OSAS groups were significantly lower than the control group (p < 0.05). The superficial and deep capillary plexus vascular density (SVD and DVD) values of the severe OSAS group were lower than the control group (p < 0.05). Serum HIF-1α and TNF-α levels of all participants were negatively correlated with both their SVD values (p < 0.05, r: -0.220 and p < 0.05, r: -0.252, respectively) and their DVD values (p < 0.001, r: -0.324 and p = 0.001, r: -0.299, respectively).

Conclusions: Increased serum levels of inflammatory mediators (HIF-1α ve TNF-α) in OSAS cause a decrease in SFCT, SVD, and DVD, which is an indication of systemic vascular damage. Further research on developing treatment strategies to modulate TNF-α ve HIF-1α may help recede vascular morbidity in OSAS patients.

Purpose: Proliferative vitreoretinopathy (PVR) can cause blindness and the pathogenesis is unclear. Transforming growth factor (TGF)-β-induced epithelial-mesenchymal transition (EMT) of RPE cells is vital. P53 protein 2 (ASPP2) was previously reported to inhibit EMT in PVR rats, but the specific mechanism is unveiled.

Methods: TGF-β was used to induce EMT in ARPE-19 cells, and evaluated by immunofluorescence and western blot. ARPE-19 cells were transfected with scrambled/ASPP2-lentivirus, followed by TGF-β treatment. After that, alterations of EMT and autophagy were measured by western blot and transmission electron microscopy. Moreover, TGF-β and ARPE-19 cells treated with scrambled/ASPP2-lentivirus were employed to establish the PVR model via intravitreal injection to SD rats, and retinal changes as well as EMT and autophagy activity were evaluated accordingly.

Results: ASPP2 expression was decreased during TGF-β-induced EMT in ARPE-19 cells. In vitro, EMT and autophagy was activated by TGF-β, which could be partly reversed by ASPP2 upregulation. In vivo, ASPP2 upregulation protected against structural and functional changes in PVR retinas. Additionally, expressions of EMT and autophagy markers in retinas were inhibited by ASPP2 upregulation.

Conclusions: ASPP2 upregulation inhibited the EMT and autophagy process caused by TGF-β in ARPE-19 cells. Correspondingly, upregulation of ASPP2 alleviated intraocular fibrosis and protected visual function in PVR rats.

Purpose: The objective of this study was to observe the macular pigment optical density (MPOD) and the relationship between MPOD and retinal thickness in Chinese primary angle-closure glaucoma (PACG) patients by the one-wavelength reflectometry method.

Methods: This study was a prospective comparative observational study, including 39 eyes from 39 PACG patients (15 men and 24 women, mean age 61.89 ± 12.30) and 41 eyes from 41 controls (20 men and 21 women, mean age 63.24 ± 14.02). We measured the MPOD 7-degree area by the one-wavelength reflectometry method and analyzed both the max and mean optical density (OD). The central retinal thickness (CRT) and the total thickness of the macular ganglion cell layer (GCL), and inner plexiform layer (IPL)were measured by spectral-domain-optical coherence tomography (SD-OCT). Statistical methods such as Shapiro-Wilk test, Fisher's exact test, chi-square test, two independent samples test and Spearman's correlation coefficient were used to observe the differences in the MPOD between normal subjects and PACG patients and the correlation between the MPOD and retinal thickness.

Results: The max optical density (Max OD) (PACG group: 0.302 ± 0.067d.u, control group: 0.372 ± 0.059d.u., p < .001) and mean optical density (Mean OD) (PACG group: 0.124 ± 0.035d.u., control group: 0.141 ± 0.028d.u., p < 0.05) were significantly reduced in PACG patients compared with control subjects. Significant decreases in GCL + IPL thickness (PACG group: 74.71 ± 39.56 μm, control group:113.61 ± 8.14 μm, p < 0.001) and CRT (PACG group: 254.49 ± 41.47 μm, control group:329.10 ± 18.57 μm, p < 0.001) were also observed in PACG eyes. There was no statistically significant correlation between the MPOD and GCL + IPL thickness (p = .639, p = .828).

Conclusions: MPOD was significantly lower in Chinese PACG patients than in the control group, potentially due to thinning of the GCL + IPL thickness. This study provides insights for the pathophysiology, assessment of PACG and potential guidance for lifestyle modifications.

Purpose: Melatonin has promising protective effects for retinopathy. However, its roles in retinopathy of prematurity (ROP) and the underlying mechanisms remain unknown. We aimed to explore its roles and mechanisms in a ROP model.

Methods: Hematoxylin and eosin staining were used to observe the morphology of the retina. Immunofluorescence was used to detect positive (Nrf2+ and VEGF+) cells. Immunohistochemistry was used to detect the level of nuclear expression of PCNA in retinal tissue. Transmission electron microscope (TEM) was used to observe the morphology and structure of pigment cells. qRT-PCR was used to assay the expression of miR-23a-3p, Nrf2, and HO-1. Western blotting was used to detect the expression of Nrf2, HO-1, β-actin, and Lamin B1.

Results: Melatonin or miR-23a-3p antagomir treatment could ameliorate the Oxygen-induced pathological changes, increased the expression of Nrf2 and HO-1, SOD, and GSH-Px, and decreased the expression of VEGF, miR-23a-3p, MDA and the apoptosis in the ROP model. Further target prediction and luciferase reporter assays confirmed the targeted binding relationship between miR-23a-3p and Nrf2.

Conclusion: Our study showed that melatonin could ameliorate H₂O₂-induced apoptosis and oxidative stress injury in RGC cells by mediating miR-23a-3p/Nrf2 signaling pathway, thereby improving retinal degeneration.

Purpose: Diabetic retinopathy (DR) is one of the most severe and common complications caused by diabetic mellites. Inhibiting NLRP3 inflammasome activation displays a crucial therapeutic value in DR. Studies have shown that KCNQ1OT1 plays a critical role in regulating NLRP3 inflammasome activation and participates in the pathogenesis of diabetic complications. The present study aims to explore the role, and the potential mechanism of KCNQ1OT1 in regulating the activation of NLRP3 inflammasome in DR.

Methods: qRT-PCR was used to detect the expression of KCNQ1OT1, miR-17-5p, TXNIP, NLRP3, ASC, caspase-1 and IL-1β. Western blot was performed to detect the expression of NLRP3, ASC, caspase-1, IL-1β and TXNIP. Immunohistochemistry and immunostaining were performed to detect the expression of caspase-1. The levels of the inflammatory cytokine IL-1β were determined by ELISA assay. FISH was used to detect the subcellular localisation of KCNQ1OT1. Bioinformatic analysis, luciferase reporter assay and in vitro studies were performed to elucidate the mechanism of KCNQ1OT1-mediated dysfunction.

Results: The expression of KCNQ1OT1 and the activation of NLRP3 inflammasome were increased in experimental DR models. KCNQ1OT1 knockdown alleviated NLRP3 inflammasome-associated molecules expression. In addition, KCNQ1OT1 was found to be localized mainly in the cytoplasm of Müller cells and facilitated TXNIP expression by acting as a miR-17-5p sponge. KCNQ1OT1 promoted the activation of NLRP3 inflammasome through miR-17-5p/TXNIP axis.

Conclusions: In conclusion, it was found in this study that KCNQ1OT1 promoted the activation of NLRP3 inflammasome both in vitro and in vivo, which was mediated by miR-17-5p/TXNIP axis. KCNQ1OT1 might be an effective interference target for the prevention and treatment of DR.

Purpose: The purpose of this study was to assess in-vitro efficacy of a suffusion of autologous serum withcyclosporine 0.05% (CsA) and sodium hyaluronate 0.1% (SH).

Methods: The expression of proinflammatory markers interleukin 6 (IL-6) and TNF-Alpha (TNF-α) in limbal epithelial cells was evaluated. Also, assessment of the stability of epithelial growth factor and transforming growth factor-beta (EGF, TGF-β) in the 50% combinations with autologous serum (AS) was done. The characteristics (pH, density, osmolality) of the two combinations were also evaluated. Additionally, cytotoxicity effect of given test compounds was evaluated on human limbal epithelial cells (LEpiC).

Results: The percentage of cells expressing IL-6 subjected to AS + SH and AS + CsA were 6.23% and 5.69% respectively. There was no significant difference in percentage of cells expressing TNF-α between the formulations (5.87%, 5.83% respectively). The growth factors; EGF and TGF-β remained stable forone month duration (on 2 and 4 weeks) at 4 °C without significant difference between the time intervals tested. The results of MTT assay suggested that limbal epithelial cells treated with AS + CsA and AS + SH combinations showed minimal toxicity however it was not significant statistically (p ≤ 0.05).

Conclusion: Two test combinations (AS + CsA, AS + SH) showed stable growth factors (EGF, TGF-β) and good anti-inflammatory property against pro-inflammatory markers. Also, the 2 combinations were found safe on cultured limbal epithelial cells. The novel combination of autologous serum in CsA may provide added benefit in dry eye disease (DED) through their combined anti-inflammatory and epitheliotropic effects.

Purpose: The aim of this study was to examine the impact of an 8-week high-speed circuit resistance training program (HSCT) on choriocapillaris density (CCD) in healthy older adults.

Methods: Eighteen cognitively normal older adults were enrolled and randomly assigned to either the HSCT or the control group (CON). The HSCT group was comprised of 11 participants who trained three times a week for eight weeks, while the CON group consisted of 7 participants who did not engage in formal training. Optical coherence tomography angiography (OCTA) was employed to image both eyes of each subject at baseline and at the 8-week follow-up. The choriocapillaris density (CCD) of 2.5 mm in diameter centered on the fovea was measured.

Results: The average age of the HSCT group was 70.3 ± 5.7 years, which was not different from the CON group (average age: 71.6 ± 5.2 years, p = 0.62). There were no significant changes in CCD between baseline and the 8-week follow-up in either the HSCT or the CON group-specifically, the baseline CCD in the HSCT group was 63.3% ± 5% (Mean ± SD), which did not differ significantly from the 8-week follow-up after HSCT training (64.7% ± 4%, p = 0.19). Likewise, there was no significant difference in CCD between baseline and the 8-week follow-up in the CON group (63.3% ± 3% and 62.7% ± 5%, respectively, p = 0.66).

Conclusion: CCD appeared to remain stable after 8 weeks of HSCT in healthy older individuals, possibly due to autoregulation. Further research with extended training may be necessary to verify these findings.

Purpose: Tear fluid gained attention as a representative biological fluid. Its simple and non-invasive collection methods as well as richness of candidate biomarkers made it a potential diagnostic tool for different diseases such as dry eye. Synchronous fluorescence spectroscopy is a highly sensitive analytical tool that results in narrowing and enhanced peak resolution, and has a potential role in disease diagnosis, biomarker identification, and therapeutic monitoring. We applied synchronous fluorescence spectroscopy to monitor variations of tear fluid composition during the development of dry eye disease and to evaluate the potential effects of phytotherapy.

Methods: Dry eye model was induced in Chinchilla rabbits by instillation of 1% atropine sulfate ophthalmic solution. Then, the tear fluid was collected at 3, 7, and 14 days and subjected to synchronous fluorescence spectroscopy. Phytotherapy was achieved by topical instillation of 20 µl of water extracts of pomegranate peel or green tea powders.

Results: The fluorescence results revealed changes in the structure of tear fluid over time and the eye is subjected to toxification due to oxidative stress. In addition, dry eye disease was found to affect the metabolic/energetic state of the eye. On the other hand, phytotherapy led to enhancement of the metabolic/biosynthesis state due to activation of flavin adenine dinucleotide-associated proteins.

Conclusion: There was change in the electrical conductivity of tear fluid proteins. In the case of dry eyes, they became electrical insulators, while in the case of treatment with extracts, their electrical conductivity properties improved. The effects of phytotherapy can be related to the high content of ellagic acid and anthocyanin of pomegranate extract, while in green tea, they are related to catechins and phenolic compounds.