The role of advanced glycation end products in modulating healthspan using C. elegans

摘要 衰老和高血糖导致一系列反应性α-二羰基化合物(α-DC， 例如乙二醛/GO、甲基乙二醛/氧化镁、3-脱氧葡萄糖/3DG)和α-DC衍生的代谢物，称为高级 糖基化终产物(AGEs)。AGEs是由于α-DC与蛋白质、脂质和dna反应而形成的。 细胞应激与特定的年龄相关过程、糖尿病并发症和神经退化有关。 因此，防止α-DC和AGE积聚对于延缓衰老和限制 各种与年龄有关的疾病的进展。理解生物化学背后的一个主要瓶颈 这些并发症的进展，以及因此快速的药物开发，是缺乏遗传上易处理的 可以在短时间内概括α-DC和年龄累积影响的模型。为此，我们 建立了一种基于乙醛酶基因受损的秀丽线虫模型，以研究α-DC和 与年龄相关的病理。这些动物表现出几种让人联想到糖尿病并发症的表型，如 由于氧化镁和年龄的积累，以及感觉过敏(或对触摸的高度敏感)，在两周内 成人期。最有趣的是，它们表明与年龄相关的神经元损伤增加，寿命缩短。 利用这个模型，我们已经确定了TRPA-1的关键作用，TRPA-1是一种瞬时受体电位(Trp)通道。 感知MGO并激活Nrf2(核因子红系2样蛋白，NFE2L2)以抵消 很久以前了。使用这个模型进行的初步药物筛选已经产生了两种有希望的化合物，它们可以改善 线虫的年龄相关病理通过激活TRPA-1/SKN-1。我们建议使用线虫作为一种 无脊椎动物模型，研究两周内年龄积累的影响，这可能需要数年时间才能形成 在人类中，允许快速发现与衰老和年龄相关的遗传和药理靶点 年龄起重要作用的疾病。 在这项建议中，我们将：1)表征TRPA-1/SKN-1在遗传学和药理学上的作用 解毒氧化镁；2)鉴定介导α-DC解毒的SKN-1下游乙醛酶 如MGO和3)研究TRPA-1/SKN-1途径在哺乳动物MGO解毒中的保守性 人类神经细胞。这些目标将有助于破译α-DC戒毒网络并识别 可减轻糖尿病并发症和延长健康寿命的治疗靶点和新化合物 糖尿病患者。

Summary Aging and hyperglycemia results in an accumulation of a series of reactive α-dicarbonyl compounds (α-DCs, e.g. glyoxal/GO, methylglyoxal/MGO, 3-deoxyglucosone/3DG) and α-DC-derived metabolites, called advanced glycation end products (AGEs). AGEs form due to the reaction of α-DCs with proteins, lipids, and DNA causing cellular stress linked with specific age-related processes, diabetic complications and neurodegeneration. Therefore, preventing α-DC and AGE buildup is of quintessential importance for slowing aging and limiting the progression of various age-related diseases. A major bottleneck in understanding the biochemistry behind the progression of these complications, and hence rapid drug development, is the lack of genetically tractable models that can recapitulate the effects of α-DC and AGE accumulation in a short time frame. To that end, we have established a Caenorhabditis elegans model based on an impaired glyoxalase gene to study α-DC and AGE-related pathologies. These animals exhibit several phenotypes reminiscent of diabetic complications, such as accumulation of MGO and AGEs, and hyperesthesia (or hyper sensitivity to touch), within two weeks of adulthood. Most interestingly they demonstrate increased age-related neuronal damage and shortened lifespan. Using this model we have identified a critical role for TRPA-1, a transient receptor potential (TRP) channel in sensing MGO and activating Nrf2 (Nuclear factor erythroid-2 like 2, or NFE2L2) to counteract the effects of AGEs. A preliminary drug screen using this model has resulted in 2 promising compounds that can ameliorate AGE-related pathologies in C. elegans through TRPA-1/SKN-1 activation. We propose to use C. elegans as an invertebrate model to study the effects of AGE accumulation within two weeks which can take years to develop in humans, to allow rapid discovery of genetic and pharmacological targets relevant to aging and age-related diseases where AGEs play an important role. In this proposal we will: 1) Characterize the role of TRPA-1/ SKN-1 both genetically and pharmacologically in detoxifying MGO; 2) Characterize the glyoxalases downstream of SKN-1 that mediate detoxification of α-DCs like MGO and 3) examine the conservation of the TRPA-1/SKN-1 pathway in detoxifying MGO in mammals using human neuronal cells. Together these aims will help to decipher the α-DC detoxification network and identify therapeutic targets and novel compounds that can mitigate diabetic complications and extend healthspan of diabetics.