In vitro pilot study of polydopamine nanoparticles as protective antioxidant agents on fibroblasts cells derived from ARSACS patients

Reactive oxygen species (ROS) are active molecules involved in several biological functions. When the production of ROS is not counterbalanced by the action of protective antioxidant mechanisms present in living organisms, a condition of oxidative stress can arise with consequent damage to biological structures. The brain is one of the main ROS-generating organs in the human body, with the consequence that most neurological disorders are associated with the overproduction of ROS. Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disease associated with mutations in the sacsin gene (SACS). At a cellular level, ARSACS is characterized by mitochondrial impairments, a reduction of bioenergetic processes, and by both an over-production of and an over sensitivity to ROS. Several antioxidant molecules have been proposed as a potential treatment for ARSACS, such as idebenone and resveratrol. Polydopamine nanoparticles (PDNPs) gained significant attention in recent years owing to their peculiar physic-chemical properties, and especially because of their antioxidant activity. PDNPs have shown a great ROS scavenging capacity that, combined with their completely organic nature that grants them the ability to be degraded and excreted by living organisms, make them a promising candidate in the treatment of oxidative stress-related disorders. In this work we assessed the effect of PDNPs upon human fibroblasts; in particular, we investigated the effects of PDNPs on populations of fibroblasts derived from healthy subjects and of fibroblasts derived from ARSACS patients, in terms of antioxidant properties and protein expression. PDNPs interaction with fibroblasts was analyzed in terms of biocompatibility, internalization and uptake pathway, reduction of ROS levels, prevention of ROS-induced apoptosis/necrosis, and protective action upon ROS-induced mitochondrial dysfunctions. Moreover, a complete proteomic analysis of the cells was performed to assess differences in terms of protein expression upon different treatments. Altogether, our data showed that PDNPs can partially counteract ROS-induced damages in both healthy and ARSACS patients-derived fibroblasts, making them a potential therapeutic candidate to treat or at least ameliorate the condition of oxidative stress associated with ARSACS disease.

活性氧（Reactive oxygen species, ROS）是参与多种生物学功能的活性分子。当生物体内活性氧的产生无法被保护性抗氧化机制所抵消时，便会引发氧化应激状态，进而对生物结构造成损伤。大脑是人体中主要产生活性氧的器官之一，因此多数神经系统疾病均与活性氧的过量产生密切相关。夏尔科-萨格奈常染色体隐性痉挛性共济失调（Autosomal recessive spastic ataxia of Charlevoix-Saguenay, ARSACS）是一种与sacsin基因（SACS）突变相关的神经退行性疾病。在细胞层面，ARSACS的病理特征表现为线粒体功能损伤、生物能代谢过程减弱，同时存在活性氧过量产生与敏感性升高的情况。目前已有多种抗氧化分子被提议作为ARSACS的潜在治疗药物，例如艾地苯醌（idebenone）与白藜芦醇（resveratrol）。聚多巴胺纳米颗粒（Polydopamine nanoparticles, PDNPs）近年来凭借其独特的理化性质，尤其是抗氧化活性，受到了广泛关注。PDNPs具备优异的活性氧清除能力，加之其完全有机的属性使其可被生物体降解并排泄，这使其成为治疗氧化应激相关疾病的极具潜力的候选方案。本研究评估了PDNPs对人成纤维细胞的作用；具体而言，我们从抗氧化特性与蛋白质表达两个维度，研究了PDNPs对健康受试者来源成纤维细胞与ARSACS患者来源成纤维细胞的影响。我们从生物相容性、细胞内化与摄取途径、活性氧水平降低、活性氧诱导的细胞凋亡/坏死预防，以及对活性氧诱导的线粒体功能障碍的保护作用等方面，分析了PDNPs与成纤维细胞的相互作用。此外，我们还对细胞开展了全面的蛋白质组学分析，以评估不同处理条件下细胞蛋白质表达的差异。综合所有实验结果，本研究表明PDNPs能够在健康受试者与ARSACS患者来源的成纤维细胞中部分抵消活性氧诱导的细胞损伤，使其成为治疗乃至至少改善ARSACS疾病相关氧化应激状态的潜在候选治疗手段。