UNDERSTANDING THE ROLE OF RETINOL DEHYDROGENASES RDH11 AND RDH12 IN VISION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 视黄醇脱氢酶RDH 12被鉴定为Leber先天性黑蒙的致病基因，这是最早和最严重的遗传性视网膜营养不良。RDH 12的生理作用尚不清楚。我们假设RDH 12使光感受器中氧化应激过程中产生的毒性分子失活。我们还假设密切相关的酶RDH 11具有相同的功能。明亮的光诱导光感受器中的氧化应激和脂质过氧化，导致毒性4-羟基壬烯醛（4-HNE）的形成。4-HNE与破坏重要细胞功能的蛋白质形成加合物。加合物在光感受器细胞凋亡之前的强光暴露期间在光感受器中积累。RDH 11和RDH 12在体外显示出减少4-HNE，并且我们发现它们保护培养的细胞和光感受器免受4-HNE诱导的加合物形成和凋亡的证据。 以下具体目标将使我们能够进一步检验我们的假设。目的1：在体外和小鼠视网膜中研究RDH 11和RDH 12对4-HNE的催化活性。目的2：确定RDH 11和RDH 12是否对体内4-HNE-蛋白加合物的形成和光感受器的凋亡具有保护作用。目的3：测试小鼠视网膜中RDH 11补偿RDH 12的假设。如果我们成功地证明RDH 11和RDH 12的生理作用是在光感受器内节中解毒4-HNE，这将产生临床影响，因为它将为治疗由于RDH 12突变而导致视力逐渐丧失的患者提供策略。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The retinol dehydrogenase RDH12 was identified as a disease-causing gene for Leber Congenital Amaurosis, the earliest and most severe inherited retinal dystrophy. The physiological role of RDH12 is unknown. We hypothesize that RDH12 inactivates toxic molecules produced during oxidative stress in photoreceptors. We also hypothesize that the closely related enzyme, RDH11, has the same function. Bright light induces oxidative stress and lipid peroxidation in photoreceptors, leading to the formation of toxic 4-hydroxynonenal (4-HNE). 4-HNE forms adduct with proteins disrupting important cellular functions. Adducts accumulate in photoreceptors during bright light exposure prior to photoreceptor apoptosis. RDH11 and RDH12 were shown to reduce 4-HNE in vitro and we found evidences that they protect cultured cells and photoreceptors against 4-HNE-induced adduct formation and apoptosis. The following specific aims will allow us to further test our hypothesis. Aim 1: Characterize the catalytic activities of RDH11 and RDH12 towards 4-HNE in vitro and in mouse retina. Aim 2: Determine whether RDH11 and RDH12 are protective against the formation of 4-HNE-protein adducts and apoptosis of photoreceptors in vivo. Aim 3: Test the hypothesis that RDH11 compensates for RDH12 in the mouse retina. If we successfully demonstrate that the physiological role of RDH11 and RDH12 is to detoxify 4-HNE in photoreceptor inner segments, this will have a clinical impact because it will provide a strategy for the treatment of patients with a progressive loss of vision due to RDH12 mutations.