PDF(Sci-hub)
Abstract：
Retinitis Pigmentosa represents a group of genetic disorders that cause progressive vision loss via degeneration of photoreceptors, but there is in principle no treatment available. For any therapy development, a deeper comprehension of the disease-leading mechanism(s) at the molecular level is needed. Here we focused on the cGMP-PKG system, which has been suggested to be a driver in several models of the disease. To gain insights in its downstream signaling we manipulated the cGMP-PKG system with the aid of organotypic retinal explant cultures from either a mouse-based disease model, i.e. the rd1 mouse, or its healthy wild-type counterpart (wt), by adding different types of cGMP analogues to either inhibit or activate PKG in retinal explants from rd1 and wt, respectively. An RNA sequencing was then performed to study the cGMP-PKG dependent transcriptome. Expression changes of gene sets related to specific pathways or functions, that fulfilled criteria involving that the changes should match PKG activation and inhibition, were determined via bioinformatics. The analyses highlighted that several gene sets linked to oxidative phosphorylation and mitochondrial pathways were regulated by this enzyme system. Specifically, the expression of such pathway components was upregulated in the rd1 treated with PKG inhibitor and downregulated in the wt with PKG activator treatment, suggesting that cGMP-PKG act as a negative regulator in this context. Downregulation of energy production pathways may thus play an integral part in the mechanism behind the degeneration for at least several RP mutations.
摘要：
色素性视网膜炎代表一组遗传性疾病，通过光感受器的变性导致进行性视力丧失，但原则上没有可用的治疗方法。对于任何治疗发展，需要在分子水平上更深入地理解疾病主导机制。这里我们关注的是cGMP-PKG系统,它被认为是几种疾病模型的驱动因素。为了深入了解其下游信号，我们借助基于小鼠的疾病模型的器官型视网膜外植体培养物操纵了cGMP-PKG系统。即rd1鼠标，或其健康的野生型对应物（wt），通过添加不同类型的cGMP类似物来抑制或激活来自rd1和wt的视网膜外植体中的PKG，分别。然后进行RNA测序以研究cGMP-PKG依赖性转录组。与特定途径或功能相关的基因集的表达变化，符合涉及变化应匹配PKG激活和抑制的标准，是通过生物信息学确定的。分析强调，与氧化磷酸化和线粒体途径相关的几个基因集受该酶系统调节。具体来说,这些途径组分的表达在用PKG抑制剂处理的rd1中上调，在用PKG激活剂处理的wt中下调，这表明cGMP-PKG在这种情况下是负调节因子。因此，能量产生途径的下调可能在至少几个RP突变的变性背后的机制中起着不可或缺的作用。
