Purchase this article with an account.
Toshiyuki Oshitari, Natsuyo Yoshida-Hata, Shuichi Yamamoto; Effect Of NT-4 On ER Stress-related Neuronal Apoptosis In Cultured Rat Retinas Exposed To High-glucose. Invest. Ophthalmol. Vis. Sci. 2011;52(14):5935.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the effect of neurotrophin-4 (NT-4) on the endoplasmic reticulum (ER) stress-related neuronal apoptosis in cultured rat retinas exposed to high-glucose (HG).
All of the procedures were performed in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. The retinas of six adult male Sprague-Dawley rats were used. After the rats were euthanized, the retinas were isolated and cultured in serum-free medium. One group of explants was cultured in 7.5 mM normal glucose (NG) and the other groups in 45 mM HG medium with and without 100 ng/ml NT-4. For osmotic control, a 7.5 mM glucose with 37.5 mM D-mannitol (NG+M) solution was used. After 7 days in culture, the explants were fixed, cryosectioned, and stained by TdT-dUTP terminal nick-end labeling (TUNEL), and also immunostained for PERK and CHOP/GADD153.
The numbers of TUNEL-positive, and PERK- and CHOP-immunopositive cells in the ganglion cell layer (GCL) were significantly higher in retinas culture in HG medium than in the NG medium and in the NG+M medium (32.5±11.6% vs. 19.9±7.2%, P=0.0007: 32.5±11.6% vs. 20.3±9.4%, P=0.0052; 30.5±17.4% vs. 12.0±4.0%, P=0.003; 30.5±17.4% vs. 12.5±7.1%, P=0.007; 21.2±7.4% vs. 11.6±8.0%, P=0.0183; 21.2±7.4% vs. 11.5±6.2%, P=0.0072). In retinas incubated in HG medium supplemented with NT-4, the numbers of TUNEL-positive, and PERK- and CHOP-immunopositive cells were significantly lower than in the HG medium without the NT-4 (14.9±5.3% vs. 32.5±11.6%, P<0.0001; 7.0±3.8% vs. 30.5±17.4%, P=0.0004; 6.9±2.9% vs. 21.2±6.5%, P=0.0004).
The neuronal cell death in retinas exposed to HG is, in part, caused by ER stress. The decrease in the number of apoptotic cells in the HG medium containing NT-4 is correlated with the suppression of the expression of PERK and CHOP, both ER stress-related factors.
This PDF is available to Subscribers Only