In Vitro Assay to Assess Chemical Toxicity in Retinal Primary Cell Cultures

描述(由申请人提供)：美国人均含有100多种工业化合物、污染物和化学品的可检测水平，但预测这种暴露的相对风险，特别是随着时间的推移，是具有挑战性的(美国疾控中心，2003)。下一代低成本高性能化合物毒性预测技术的成功开发和商业化将有助于评估环境暴露的安全水平，从而降低国家医疗成本并创造更安全的工作/生活环境。这种对环境毒素的暴露在衰老和氧化过程中发挥着重要作用，这是导致黄斑变性的关键风险因素，而黄斑变性是最终导致失明的过程。然而，重要的是，目前还没有公认的或实际的测试来直接测量化合物的视网膜毒性。进行视网膜毒性的体内评估时，需要大量的动物，既耗时又昂贵，而且不提供毒性进展的数据。在体外制备稳定的原代混合视网膜培养物的能力将允许以快速和经济有效的方式筛选和优先进行进一步的毒性测试。理想情况下，这样的系统应该能够区分光依赖毒性[光毒性]和一般毒性效应，并将模拟体内毒性。因此，这个多阶段SBIR项目的总体目标是开发、验证Acucela专有视网膜培养筛选系统Ocuscreen(Tm)并将其商业化，作为下一代体外系统，用于对环境毒素的相对(照片)毒性进行排名，并将该检测纳入化学品商业化监管框架的一部分。该项目第一阶段的具体目标是识别一组已知的视网膜毒物，证明对其(照片)毒性潜力进行排名的可行性，并最终显示这些排名与体内文献数据的相关性。证明我们可以预测一小类代表性化合物的(照片)毒性(或缺乏毒性)，这将在第一阶段概念验证项目的有限范围内建立我们新系统的预测潜力，并将为更大的第二阶段示范工作奠定基础。第一阶段还将为Ocuscreen被提名为替代方法验证机构间协调委员会(ICCVAM)的替代测试方法提供足够的数据，并将使我们能够确定Ocuscreen达到ICCVAM性能标准的程度。第二阶段的工作将涉及建立一个大型的化学品光感受器毒性数据库--根据现有知识和我们的检测系统的结果建立--以提高化合物安全性的预测准确性。该项目的第三阶段将侧重于建立光感受器毒性的商业筛查服务。即使没有正式的监管采用，准确预测有毒潜力的能力也将为化学公司提供令人信服的服务，并将代表着保护人类健康的重要一步。在美国，人均含有100多种可检测到的工业化合物、污染物和化学品，但预测这种暴露的风险，特别是眼睛毒性，是具有挑战性的。目前的预测方法需要大量的动物，既耗时又昂贵，而且没有提供毒性进展的数据。该项目的总体目标是开发、验证Acucela的专有视网膜培养筛选系统，并将其商业化，作为评估环境毒物对健康影响的下一代实用体外系统。

DESCRIPTION (provided by applicant): The average person in the U.S. contains detectable levels of more than 100 industrial compounds, pollutants, and chemicals, but predicting the relative risk of this exposure, especially over time, is challenging (US CDC, 2003). Successful development and commercialization of next-generation, low-cost, high-performance technology for predicting compound toxicity would help assess safe levels of environmental exposure-thereby reducing national healthcare costs and producing safer working/living environments. This exposure to environmental toxins plays an important role in aging and oxidation processes, which are key risk factors of macular degeneration, a process that eventually leads to blindness. Importantly, however, there are currently no accepted or practical tests for measuring the retinal toxicity of compounds directly. In vivo assessments of retinal toxicity, when performed, require large numbers of animals, are time-consuming and expensive, and do not provide data on toxicity progression. The ability to prepare stable primary mixed retinal cultures in vitro would allow screening and prioritization of further toxicity testing in a rapid and cost-effective manner. Ideally, such a system should allow differentiation of light-dependent toxicity [phototoxicity] and general toxic effects, and would mimic in vivo toxicity. Therefore, the overall goal of this multi-phase SBIR project is to develop, validate, and commercialize Ocuscreen(tm), Acucela's proprietary retinal culture screening system, as a next-generation in vitro system for ranking the relative (photo)toxicity of environmental toxins, and to have this assay incorporated as a part of the regulatory framework for the commercialization of chemicals. The Specific Aims for Phase I of this project are to identify a group of known retinal toxicants, to prove the feasibility of ranking their (photo)toxic potential, and finally to show these rankings correlate with in vivo literature data. Demonstrating that we can predict (photo)toxicity (or lack thereof) in a small class of representative compounds will establish the predictive potential of our new system within the limited scope of the Phase I proof-of-concept project, and will set the stage for a larger Phase II demonstration effort. Phase I will also provide sufficient data for Ocuscreen to be nominated as an alternative test method to the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), and will allow us to determine how well Ocuscreen meets ICCVAM performance standards. Phase II work will involve establishing a large photoreceptor toxicity database of chemicals-built both from existing knowledge and results from our assay system-to improve the predictive accuracy of compound safety. Phase III of the project will be focused on establishing a commercial screening service for photoreceptor toxicity. Even without formal regulatory adoption, the ability to accurately predict toxic potential will provide a compelling service to chemical companies and will represent an important step in protecting human health. The average person in the U.S. contains detectable levels of more than 100 industrial compounds, pollutants, and chemicals, but predicting the risk of this exposure, especially to eye toxicity, is challenging. Current prediction methods require large numbers of animals, are time-consuming and expensive, and do not provide data on toxicity progression. The overall goal of this project is to develop, validate, and commercialize Acucela's proprietary retinal culture screening system as a next-generation, practical in vitro system for evaluating the health effects of environmental toxicants.