D609 protects retinal pigmented epithelium as a potential therapy for age-related macular degeneration

Abstract

Accumulated oxidative damage may lead to irreversible retinal pigmented epithelium (RPE) cell death, which is considered to be the primary cause of dry age-related macular degeneration (AMD), leading to blindness in the elderly. However, an effective therapy for this disease is lacking. Here, we described a robust high-content screening procedure with a library of 814 protective compounds and found that D609 strongly protected RPE cells from sodium iodate (SI)-induced oxidative cell death and prolonged their healthy survival. D609 effectively attenuated excessive reactive oxygen species (ROS) and prevented severe mitochondrial loss due to oxidative stress in the RPE cells. Surprisingly, the potent antioxidative effects of D609 were not achieved through its own reducibility but were primarily dependent on its ability to increase the expression of metallothionein. The injection of this small water-soluble molecule also showed an explicit protective effect of the RPE layer in an SI-induced AMD mouse model. These findings suggested that D609 could serve as a novel antioxidative protector of RPE cells both in vitro and in vivo and unveiled a novel antioxidative mechanism of D609, which may ultimately have clinical applications for the treatment of AMD.Signal Transduction and Targeted Therapy (2020) 5:20; https://doi.

D609 inhibition of phosphatidylcholine-specific phospholipase C attenuates prolonged insulin stimulation-mediated GLUT4 downregulation in 3T3-L1 adipocytes

“…They were in agreement with those of earlier reports indicating that PC-PLC activity is regulated in a redox-dependent manner [ 16 ] and implicate in the NADPH oxidase cascade that regulates cigarette smoke extract induce heme oxygenase-1 expression in mouse brain endothelial cells [ 24 ]. A recent study reported that in the retinal pigmented epithelium, D609 achieves its antioxidant effects primarily through elevating the expression of the metallothionein (MT) family, which is well known for its ability to eliminate oxidative risk factors [ 33 ]. In our study, the real-time measurement results of pHyPer fluorescence also show that D609 blocked insulin-generated oxidative stress in 3T3-L1 adipocytes.…”

“…Tricyclodecan-9-yl-xanthogenate (D609) has antioxidant properties in many cell types [ 30 , 33 , 36 ] and scavenges H 2 O 2 [ 14 ]. It is also a selective competitive inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC) which breaks down phosphatidylcholine (PC) to 1, 2-diacylglycerol (DG) and phosphocholine (PCho).…”

TLR4-Dependent DUOX2 Activation Triggered Oxidative Stress and Promoted HMGB1 Release in Dry Eye

“…The level of ROS was measured using a 2',7'-dichlorofluorescein diacetate (H2DCFDA) assay kit as described in our previous study ( 21 ). In brief, HCE cells were seeded in 6-well plates.…”

Antioxidant Defenses in the Human Eye: A Focus on Metallothioneins

“…In connection with the above, Choudhary et al, 2005 [ 313 ] reported that ARPE-19 treated with a thionein hexapeptide H-Lys-Cys-Thr-Cys-Cys-Ala-OH, which is a fragment of mouse liver MT1 [ 314 , 315 ] significantly protected against H 2 O 2 and 4-hydroxynonenal (HNE)-induced mitochondrial depolarization and ameliorated H 2 O 2 and HNE-induced apoptosis. Additional evidence about the antioxidant properties of MTs were collected in the recent work of Wang et al, 2020 [ 316 ] on ARPE-19 cells exposed to sodium iodate-induced oxidative damage. In this study, cells transfected with overexpression plasmids of MT2A and MT1G genes showed a higher cell survival rate than control cells after exposure to sodium iodate (10 µM for 18 h).…”