Reduced Retinal Degeneration in an Oxidative Stress Organ Culture Model through an iNOS-Inhibitor
by
, and
Ana M. Mueller-Buehl
1,†, 
Teresa Tsai
1,†,
José Hurst
2,
Carsten Theiss
3
,
Laura Peters
1,
Lisa Hofmann
1,
Fenja Herms
1,4,
Sandra Kuehn
1,
Sven Schnichels
2,*,†
and
Stephanie C. Joachim
1,*,†
1
Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23–25, 44892 Bochum, Germany
2
Center for Ophthalmology Tübingen, University Eye Hospital Tübingen, 72076 Tübingen, Germany
3
Department of Cytology, Institute of Anatomy, Ruhr-University Bochum, 44801 Bochum, Germany
4
Clinic for Small Mammals, Reptiles and Birds, University of Veterinary Medicine, 30559 Hannover, Germany
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Biology 2021, 10(5), 383; https://doi.org/10.3390/biology10050383
Submission received: 22 February 2021
/
Revised: 9 April 2021
/
Accepted: 26 April 2021
/
Published: 28 April 2021
(This article belongs to the Special Issue Glaucoma – Pathophysiology and Therapeutic Options)
Simple Summary
There is an urgent need to develop new therapeutic approaches for diseases of the retina, like glaucoma. In their pathogenesis, oxidative stress and the corresponding defense reactions play an important role. In porcine retinal organ cultures, hydrogen peroxide can be used to simulate oxidative stress. In the present study, we investigated whether the treatment with an inducible nitric oxide synthase inhibitor protects retinal cells from oxidative stress. Therefore, porcine retinal explants were damaged with hydrogen peroxide and treated with the nitric oxide synthase inhibitor. Analyzes of the retina at four and eight days showed that a inhibitor was able to prevent degeneration in porcine retinas, since retinal ganglion cells were protected to some extent. Moreover, in the later course, there was also protection of other retinal cells (bipolar cells). Hence, this inhibitor seems to be a promising treatment option for retinal diseases.
Abstract
In retinal organ cultures, H2O2 can be used to simulate oxidative stress, which plays a role in the development of several retinal diseases including glaucoma. We investigated whether processes underlying oxidative stress can be prevented in retinal organ cultures by an inducible nitric oxide synthase (iNOS)-inhibitor. To this end, porcine retinal explants were cultivated for four and eight days. Oxidative stress was induced via 300 µM H2O2 on day one for three hours. Treatment with the iNOS-inhibitor 1400 W was applied simultaneously, remaining for 72 h. Retinal ganglion cells (RGC), bipolar and amacrine cells, apoptosis, autophagy, and hypoxia were evaluated immunohistologically and by RT-qPCR. Additionally, RGC morphology was analyzed via transmission electron microscopy. H2O2-induced RGCs loss after four days was prevented by the iNOS-inhibitor. Additionally, electron microscopy revealed a preservation from oxidative stress in iNOS-inhibitor treated retinas at four and eight days. A late rescue of bipolar cells was seen in iNOS-inhibitor treated retinas after eight days. Hypoxic stress and apoptosis almost reached the control situation after iNOS-inhibitor treatment, especially after four days. In sum, the iNOS-inhibitor was able to prevent strong H2O-induced degeneration in porcine retinas. Hence, this inhibitor seems to be a promising treatment option for retinal diseases.
