NF-E2 related factor 2 (Nrf2) is a key transcription factor that plays a pivotal role in endogenous protection against oxidative stress. However, the role of Nrf2 in visual disorders remains unclear. It has been reported that oxidative stress is thought of as one of the causes of glaucoma. Here, we investigate whether the function of Nrf2 in oxidative stress-induced retinal ganglion cell (RGC) death. This study used adult male Nrf2 deficient mice (Nrf2 KO) and age-and sex-matched wild-type (WT) mice. We dissociated and purified N-4-[4-didecylaminostryryl]-N-methyl-pyridinium iodide-labeled RGCs with fluorescence-activated cell sorting, and tried to detect the Nrf2 and Keap1 genes. In the absence of nerve crush (NC), the number of RGCs in Nrf2 KO mice was almost same as that in WT mice. 1-(2-cyano-3-, 12-dioxooleana-1, 9 (11)-dien-28-oyl) imidazole (CDDO-Im), an Nrf2 activator, prevented NCinduced loss of RGCs in WT mice. Seven days after NC, without treatment, the number of RGCs in Nrf2 KO mice was significantly lower than in WT mice. In addition, after CDDO-Im treatment, quantitative RT-PCR showed increased expression of antioxidant and phase II detoxifying enzymes. These results suggest that up-regulation of Nrf2 signaling after CDDO-Im treatment may be a novel therapeutic strategy for the protection of RGCs, especially in glaucoma.
The results indicated that oral K-115 administration delayed RGC death. Although K-115 may be mediated through Nox1 downregulation, we found that it did not suppress ROS production directly. Our findings show that K-115 has a potential use in neuroprotective treatment for glaucoma and other neurodegenerative diseases.
Calpain, an intracellular cysteine protease, has been widely reported to be involved in neuronal cell death. The purpose of this study is to investigate the role of calpain activation in axonal damage-induced retinal ganglion cell (RGC) death. Twelve-week-old male calpstatin (an endogenous calpain inhibitor) knockout mice (CAST KO) and wild-type (WT) mice were used in this study. Axonal damage was induced by optic nerve crush (NC) or tubulin destruction induced by leaving a gelatin sponge soaked with vinblastine (VB), a microtubule disassembly chemical, around the optic nerve. Calpain activation was assessed by immunoblot analysis, which indirectly quantified the cleaved α-fodrin, a substrate of calpain. RGCs were retrogradely labeled by injecting a fluorescent tracer, Fluoro-Gold (FG), and the retinas were harvested and flat-mounted retinas prepared. The densities of FG-labeled RGCs harvested from the WT and CAST KO groups were assessed and compared. Additionally, a calpain inhibitor (SNJ-1945, 100 mg/kg/day) was administered orally, and the density of surviving RGCs was compared with that of the vehicle control group. The mean density of surviving RGCs in the CAST KO group was significantly lower than that observed in the WT group, both in NC and in VB. The mean density of surviving RGCs in the SNJ-1945-treated group was significantly higher than that of the control group. The calpain inhibitor SNJ-1945 has a neuroprotective effect against axonal damage-induced RGC death. This pathway may be an important therapeutic target for preventing this axonal damage-induced RGC death, including glaucoma and diabetic optic neuropathy and other CNS diseases that share a common etiology.
The detection rates and levels of various cytokines had different patterns in POAG and NVG patients, suggesting distinctive alterations in the microenvironment in different types of glaucoma.
Abstract:We demonstrate a prototype system of polarization-sensitive optical coherence tomography (PS-OCT) designed for clinical studies of the anterior eye segment imaging. The system can measure Jones matrices of the sample with depth-multiplexing of two orthogonal incident polarizations and polarization-sensitive detection. An optical clock is generated using a quadrature modulator and a logical circuit to double the clock frequency. Systematic artifacts in measured Jones matrices are theoretically analyzed and numerically compensated using signals at the surface of the sample. Local retardation images of filtering blebs after trabeculectomy show improved visualization of subconjunctival tissue, sclera, and scar tissue of the bleb wall in the anterior eye segment. 37. B. Braaf, K. A. Vermeer, M. de Groot, K. V. Vienola, and J. F. de Boer, "Fiber-based polarization-sensitive OCT of the human retina with correction of system polarization distortions," Biomed.
We found a close relationship between cpRNFLT, MD, tissue MBR, SAF and 8-OHdG, suggesting that systemic oxidative stress is associated with decreased ocular blood flow and may be involved in the pathogenesis of NTG.
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