Diabetic retinopathy (DR) is a common diabetic complication known to cause vision impairment and blindness. Previous studies have demonstrated that proanthocyanidins (PACs), polyphenols that are naturally found in several plants and fruits, have powerful antioxidant and anti-inflammatory effects on various cells. However, the effects and underlying mechanism of PACs against DR pathogenesis remain unknown. Here, we investigated the proliferation, apoptosis, and mechanisms of ARPE-19 cells in response to oxidative stress and inflammation under high-glucose conditions with or without PACs treatment. The Cell-Counting Kit-8 assay and western blot analysis showed that treatment with 10 μl PACs significantly increased cell proliferation and the expression level of Bcl-2 in ARPE-19 cells under highglucose conditions. Moreover, PACs attenuated the high glucose-induced apoptosis, and the increased expression levels of caspase-3 and Bax. Under high-glucose conditions, the generation of reactive oxygen species (ROS) and levels of malondialdehyde increased, whereas the superoxide dismutase content decreased.Moreover, the expression level of the NLRP3 inflammasome, and the release of interleukin 1β (IL-1β) and IL-18 increased. PACs reversed all of these high glucoseinduced effects on ARPE-19 cells. Additionally, exposure to nigericin sodium salt, an agonist of the NLRP3 inflammasome, upregulated expression of the NLRP3 inflammasome accompanied by the release of IL-1β and IL-18. Again, treatment with PACs markedly downregulated these effects. Collectively, these results demonstrate that PACs can prevent retinal pigment epithelial cells from high glucose-induced injury via inhibiting the generation of ROS and activation of the NLRP3 inflammasome, suggesting PACs as a potential candidate for the management of DR.
Nanoparticle-mediated laser-induced breakdown (LIB) can be used for
Nanoparticle synthesis, cell nanosurgery and laser-induced breakdown
spectroscopy (LIBS). To investigate the photo-thermal conversion of gold
nanoparticles during pulsed laser irradiation, the electron-phonon
two-temperature model was established in this study. The impact of laser
energy density and pulse width on the thermal conversion and morphology
change of gold nanorods were investigated and compared with experimental
observations. The results show that the melting threshold of gold nanorods
under nanosecond laser irradiation is about twenty times that of femtosecond
laser irradiation. The mechanisms of nanorod fragmentation are
different between fem to and nanosecond laser irradiation: particle melting is
more likely to occur in nanosecond laser irradiation, while the Coulomb
explosion is highly likely to occur in femtosecond laser irradiation.
Background: SD-OCT is becoming commonplace in everyday practice. Vitreomacular adhesions (VMAs) are being more routinely diagnosed. Predictive studies to the natural course of VMA are thus clinically significant. Spectral domain-optical coherence tomography (SD-OCT) was presently utilized to analyze the incidence of floaters, the complete vitreomacular separation or VMA, the VMA complication, the vitreomacular angle (VMAng), and the complication mechanism. Methods: Monthly SD-OCT was performed on patients with/without symptomatic floaters. OCT allowed VMA and vitreomacular separation to be compared. The incidence was assessed applying one-tailed Fisher's exact tests. The VMAngs between the inner retina and posterior hyaloid were measured, and the complication mechanism was studied using OCT image. For macular hole (MH), pre-and/or post-operative best corrected visual acuities (BCVAs; LogMAR), refractions and photoreceptor conditions were also evaluated. Results: Totally, 124 eyes were included; there were 116 eyes with VMA and 8 eyes with vitreomacular separation. Considering the percentages over 124 eyes, floaters were present in 14.5% of enrolled eyes (=18/124), consisting of 12.9% of eyes with VMA (16/124) and 1.6% of eyes with vitreomacular separation (2/124). Moreover, there were twelve eyes (9.7%) with VMA-associated vision-threatening complications, including MH (n = 8; 6.5%), retinal detachment (RD; n = 2; 1.6%), vitreomacular traction (VMT; n = 1; 0.8%) and macular pucker (MP; n = 1; 0.8%). Eyes with initial VMA had a significantly greater possibility of complications than eyes with initial vitreomacular separation (p = 0.03). Among these eyes with MH (n = 8), the pre-operative BCVA (LogMAR) was 1.1 ± 0.5, which was insignificantly (p = 0.35) improved to 0.8 ± 0.7 post-operatively. The VMAng of VMA eyes with MHs was 24.2 ± 24.9°( n = 8). The critical VMAng was 13.3°.
(Continued on next page)Conclusions: A minority of eyes with VMA or vitreomacular separation had floaters. Moreover, the use of SD-OCT could identify vision-threatening sequelae, namely MH, RD, MP and VMT, and this was significantly more frequent in eyes with VMA than in eyes with complete vitreomacular separation. Therefore, SD-OCT might be a useful way of identifying either identity, and evaluating VMA-associated complications. Whether VMA eyes with MH (n = 8) that have a VMAng greater than critical VMAng have a greater likelihood of tangential traction and subsequent MH needs further investigation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.