Mueller-Buehl Ana M, Doepper Hannah, Grauthoff Sven, Kiebler Tobias, Peters Laura, Hurst José, Kuehn Sandra, Bartz-Schmidt Karl U, Dick H Burkard, Joachim Stephanie C, Schnichels Sven
Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany.
Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany.
Clin Exp Ophthalmol. 2020 Jul;48(5):666-681. doi: 10.1111/ceo.13731. Epub 2020 Mar 10.
Hydrogen peroxide (H O ) can be used in vitro to simulate oxidative stress. In retinal organ cultures, H O induces strong neurodegeneration of the retina. It is known that oxidative stress plays a role in the development of several retinal diseases including glaucoma and ischemia. Thus, we investigated whether processes underlying oxidative stress can be prevented by hypothermia using an ex vivo organ culture model of porcine retinas.
Porcine retinal explants were cultivated for 5 and 8 days. Oxidative stress was induced via 300 μM H O on day 1 for 3 hours. Hypothermia treatment at 30°C was applied simultaneously with H O , for 3 hours. Retinal ganglion cells (RGCs), apoptosis, bipolar and cholinergic amacrine cells, microglia and macroglia were evaluated immunohistologically. Apoptosis rate was additionally analysed via western blot.
Reduced apoptosis rates through hypothermia led to a preservation of RGCs (P < .001). Amacrine cells were rescued after hypothermia treatment (P = .17), whereas bipolar cells were only protected partly. Additionally, at 8 days, microglial response due to oxidative stress was completely counteracted via hypothermia (P < .001).
H O induced strong degenerative processes in porcine retinas. The role of oxidative stress in the progression of retinal diseases makes this ex vivo organ culture model suitable to investigate new therapeutic approaches. In the present study, the damaging effect of H O to several retinal cell types was counteracted or strongly alleviated through hypothermia treatment. Especially RGCs, which are affected in glaucoma disease, were protected due to a reduced apoptosis rate through hypothermia.
过氧化氢（H₂O₂）可在体外用于模拟氧化应激。在视网膜器官培养中，H₂O₂可诱导视网膜强烈的神经退行性变。已知氧化应激在包括青光眼和缺血在内的几种视网膜疾病的发展中起作用。因此，我们使用猪视网膜的离体器官培养模型研究低温是否可以预防氧化应激相关过程。
猪视网膜外植体培养5天和8天。在第1天通过300μM H₂O₂诱导氧化应激3小时。在给予H₂O₂的同时进行30°C的低温处理，持续3小时。通过免疫组织化学评估视网膜神经节细胞（RGCs）、细胞凋亡、双极细胞和胆碱能无长突细胞、小胶质细胞和大胶质细胞。另外通过蛋白质印迹分析细胞凋亡率。
低温降低细胞凋亡率，从而使RGCs得以保留（P <.001）。低温处理后无长突细胞得到挽救（P = 0.17），而双极细胞仅得到部分保护。此外，在第8天，低温完全抵消了氧化应激引起的小胶质细胞反应（P <.001）。
H₂O₂在猪视网膜中诱导了强烈的退行性变过程。氧化应激在视网膜疾病进展中的作用使得这种离体器官培养模型适合研究新的治疗方法。在本研究中，通过低温处理抵消或显著减轻了H₂O₂对几种视网膜细胞类型的损伤作用。特别是在青光眼疾病中受影响的RGCs，由于低温降低了细胞凋亡率而得到保护。
