Department of Anatomy and the State Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
PLoS One. 2013 Jul 19;8(7):e68881. doi: 10.1371/journal.pone.0068881. Print 2013.
Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP) are neuroprotective for retinal ganglion cells (RGCs) in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT) model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT) model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK) pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1). This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina.
我们的研究小组已经表明，从枸杞（枸杞）中提取的多糖对不同动物模型的视网膜神经节细胞（RGC）具有神经保护作用。保护 RGC 免受继发性变性是治疗青光眼管理的一个有前途的方向。完全视神经横断（CONT）模型可用于研究 RGC 的原发性变性，而部分视神经横断（PONT）模型可用于研究 RGC 的继发性变性，因为在该模型中，RGC 的原发性变性和继发性变性可以在同一视网膜的位置上分开；在其他情况下，这两种类型的变性很难区分。为了研究枸杞可以延迟哪种变性，本研究同时使用了 CONT 和 PONT 模型。从手术前 7 天开始，大鼠每天喂食枸杞或载体，直到不同时间点处死，并评估 RGC 的存活数量。用 Western-blot 分析检测与炎症、氧化应激和 c-jun N 末端激酶（JNK）途径相关的几种蛋白质的表达。枸杞既不能延迟 CONT 后 RGC 的原发性变性，也不能延迟 PONT 后 RGC 的继发性变性。我们发现，枸杞通过抑制氧化应激和 JNK/c-jun 途径以及短暂增加胰岛素样生长因子-1（IGF-1）的产生，似乎发挥了这些保护作用。这项研究表明，枸杞可以延迟 RGC 的继发性变性，这种作用可能与抑制视网膜中的氧化应激和 JNK/c-jun 途径有关。
