scholarly journals Rodent Anterior Ischemic Optic Neuropathy (rAION) Induces Regional Retinal Ganglion Cell Apoptosis with a Unique Temporal Pattern

2008 ◽  
Vol 49 (8) ◽  
pp. 3671 ◽  
Author(s):  
Bernard J. Slater ◽  
Zara Mehrabian ◽  
Yan Guo ◽  
Allan Hunter ◽  
Steven L. Bernstein
Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1466
Author(s):  
Jia-Ying Chien ◽  
Yu-Yau Chou ◽  
Jhih-Wei Ciou ◽  
Fang-Yun Liu ◽  
Shun-Ping Huang

Nonarteritic anterior ischemic optic neuropathy (NAION) is one of the most common acute optic neuropathies that affect the over 55-year-old population. NAION causes the loss of visual function, and it has no safe and effective therapy. Bardoxolone methyl (methyl 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oate; CDDO-Me; RTA 402) is a semisynthetic triterpenoid with effects against antioxidative stress and inflammation in neurodegeneration and kidney disease that activates the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Moreover, RTA 402 is an FDA-approved compound for the treatment of solid tumors, lymphoid malignancies, melanoma, and chronic kidney disease. Omaveloxolone (RTA 408) is an activator of Nrf2 and an inhibitor of NFκB, possessing antioxidative and anti-inflammatory activities in mitochondrial bioenergetics. RTA 408 is also under clinical investigation for Friedreich ataxia (FA). In this study, a rodent anterior ischemic optic neuropathy (rAION) model induced by photothrombosis was used to examine the therapeutic effects of RTA 402 and RTA 408. Treatment with RTA402 results in antiapoptotic, antioxidative stress, anti-inflammatory, and myelin-preserving effects on retinal ganglion cell (RGC) survival and visual function via regulation of NQO1 and HO-1, reduced IL-6 and Iba1 expression in macrophages, and promoted microglial expression of TGF-β and Ym1 + 2 in the retina and optic nerve. However, these effects were not observed after RTA 408 treatment. Our results provide explicit evidence that RTA 402 modulates the Nrf2 and NFκB signaling pathways to protect RGCs from apoptosis and maintain the visual function in an rAION model. These findings indicate that RTA 402 may a potential therapeutic agent for ischemic optic neuropathy.


2021 ◽  
Vol 9 (1) ◽  
pp. 28-33
Author(s):  
L.P. Novak ◽  
O.V. Tumanova

Decrease and loss of vision are extremely important problems, quite common conditions that lead to disability. The most common causes are ischemic optic neuropathy, diabetic retinopathy, and amblyopia. The pathogenesis of these disea­ses is characterized by neurodegeneration, loss of structure and function of neurons. Citicoline may be considered for neuroprotection as the drug of choice in these clinical situations. Citicoline has antioxidant and anti-inflammatory properties, it reduces lipid peroxidation and the formation of free radicals, has anti-apoptotic and membrane-protective effects. The drug has a neuromodulatory effect and also contributes to the pre­servation of sphingomyelin, which ensures signal transmission in nerve cells. In ischemic optic neuropathy, oral citicoline can reduce nerve fiber loss and improve retinal ganglion cell function and visual tract function. In diabetic retinopathy, citicoline prevents synapse loss and improves macular and retinal ganglion cell function. In amblyopia, citicoline stimulates the function of neurotransmitters and neuromodulators, including an increase in the activity of endogenous dopamine and, at the same time, an improvement in the vascular aspects of neurological function. Axobrex is a convenient oral form of citicoline. With oral administration, the bioavailability of citicoline exceeds 90 %, Axobrex is non-toxic and very well-tolerated. The dosage regimen of Axobrex is simple, which contributes to satisfactory patient adherence to treatment. The use of Axobrex in patients with ischemic optic neuropathy, diabetic retinopathy, and amblyopia has an optimal balance of benefits and safety and is advisable for neuroprotection.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 902
Author(s):  
Jia-Ying Chien ◽  
Shu-Fang Lin ◽  
Yu-Yau Chou ◽  
Chi-Ying F. Huang ◽  
Shun-Ping Huang

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common cause of acute vision loss in older people, and there is no effective therapy. The effect of the systemic or local application of steroids for NAION patients remains controversial. Oroxylin A (OA) (5,7-dihydroxy-6-methoxyflavone) is a bioactive flavonoid extracted from Scutellariae baicalensis Georgi. with various beneficial effects, including anti-inflammatory and neuroprotective effects. A previous study showed that OA promotes retinal ganglion cell (RGC) survival after optic nerve (ON) crush injury. The purpose of this research was to further explore the potential actions of OA in ischemic injury in an experimental anterior ischemic optic neuropathy (rAION) rat model induced by photothrombosis. Our results show that OA efficiently attenuated ischemic injury in rats by reducing optic disc edema, the apoptotic death of retinal ganglion cells, and the infiltration of inflammatory cells. Moreover, OA significantly ameliorated the pathologic changes of demyelination, modulated microglial polarization, and preserved visual function after rAION induction. OA activated nuclear factor E2 related factor (Nrf2) signaling and its downstream antioxidant enzymes NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase 1 (HO-1) in the retina. We demonstrated that OA activates Nrf2 signaling, protecting retinal ganglion cells from ischemic injury, in the rAION model and could potentially be used as a therapeutic approach in ischemic optic neuropathy.


2018 ◽  
Vol 12 ◽  
Author(s):  
Wanjing Huang ◽  
Fengjuan Gao ◽  
Fangyuan Hu ◽  
Jiancheng Huang ◽  
Min Wang ◽  
...  

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