2018-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/683353摘要：芬普尼為世界上普遍使用之廣效性苯唑類殺蟲劑及獸醫用藥。根據國家衛生研究院研究指出芬普尼為本國常見超標使用的農藥，最近因為違法於養雞場作為除&#34766;之使用提高人類暴露芬普尼的健康風險疑慮。研究指出給予芬普尼的實驗動物會出現神經系統紊亂與造成肝、腎臟的氧化性傷害；且其為已知的內分泌干擾物質具有干擾正常生理功能包括免疫系統恆定的潛在毒性作用。然而目前有關其免疫毒性的研究仍顯不足。根據我們團隊使用毒理基因體學研究的策略發現芬普尼交互作用的基因可能會引起免疫相關的疾病，有待利用免疫毒理研究的方法深入探討其免疫毒性的作用濃度與機制。雖然文獻指出芬普尼會抑制人類單核球分泌介白素-1b及腫瘤壞死因子-a，並會造成人類周邊血液淋巴球的染色體傷害，然而目前對於芬普尼如何影響免疫反應仍有待進一步的研究。T 細胞參與許多重要的後天免疫反應的調控，胸腺為免疫系統中重要的器官，為T細胞前驅細胞分化的重要場所，且在有外來刺激環境下具有維持免疫系統恆定的重要功能。胸腺對於許多具有免疫毒性的毒化物非常敏感，可能會藉由導致胸腺萎縮或T細胞發育調控失常而引起免疫抑制或免疫平衡失調。根據目前正在執行的計畫成果顯示芬普尼會干擾成熟T細胞抗原專一性的免疫反應，本延續性的計畫預計探討活體與離體暴露芬普尼對於早期T細胞發育的影響及探討其作用機制。藉由偵測芬普尼引起氧化性物質(ROS)的種類將可幫助找出具有緩解其造成免疫毒性的有效藥物。本計畫的預計工作如下:工作項目一: 探討芬普尼對於胸腺細胞發育的影響與作用機制。四周齡大的BALB/c小鼠會給予不同濃度的芬普尼，並進一步偵測其對胸腺細胞組成、組織病理變化及胸腺細胞功能的影響。有關芬普尼干擾T細胞發育的機轉研究，擬定針對參與胸腺細胞發育重要的細胞激素與趨化因子網絡(例如介白素-2、介白素-7、幹細胞因子、CCR4受器、CCR7受器、介白素-7受器等)及重要的轉錄因子(FoxN1、Lyl1、 Aire及Soxl3)進行探討。工作項目二: 探討氧化性傷害與細胞凋亡參與芬普尼引起免疫毒性之角色。芬普尼已知可造成神經細胞與肝臟細胞的氧化性傷害，由於T細胞對於ROS非常敏感，藉由探討芬普尼於胸腺細胞引起ROS的種類及其參與細胞激素製造與引起凋亡的影響，將有助於尋找具有潛在預防其引起免疫毒性的的抗氧化物質。此外會深入探討芬普尼誘導凋亡的細胞訊息路徑。<br> Abstract: Fipronil (FIP) is widely used as a broad-spectrum phenylpyrazole insecticide and veterinary drug in the world. In Taiwan, it has been reported as one of the most exceed-standard used pesticides by National Health Research Institutes. Recently, the illegal use of fipronil against red mite (Dermanyssus gallinae) on poultry farms raises the concern about the effects of dietary exposure to fipronil on human health. Neurological disturbances, induction of oxidative stress in the liver and kidney have been reported in the fipronil-treated animals. Fipronil is characterized as an endocrine disruptor, which is generally believed to possess adverse effects on non-reproductive tissues, notably the immune system. The current experimental evidence regarding the immunotoxic properties of fipronil was insufficient. Fipronil is inferred to be potentially associated with immune-related diseases by in silico toxicogenomics approaches. Although it has been reported that fipronil may decrease the production of IL-1β and TNF-α by human monocytes and induce DNA damage in human peripheral blood lymphocyte, the influence of fipronil on the immune responses has not been thoroughly studied. In addition, little evidence provides the mechanisms involved in fipronil-mediated immunotoxicity. T cells, the important effector cells of acquired immunity, participate in a wide variety of immune responses. The thymus represents a major component of the immune system, where T cell progenitors undergo differentiation, and plays a crucial role in the maintain homeostasis of immune system under conditions of external threats. The thymus is a very sensitive target for immunotoxic toxicants, which may lead to thymus atrophy and the dysregulation of T cell development. In our current study, the T cell functionality was disturbed by fipronil. The objective of the proposed research project is to further study the immunotoxic effects of fipronil on the early stage of T cells and to elucidate the underlying mechanisms. In addition, to clarify the generation of reactive oxygen species (ROS) by fipronil will help to identify the effective antioxidants to alleviate its immunotoxicity. Specifically, a series of related specific aims (SA) will be addressed, including: SA1: To investigate the effects of fipronil on thymopoiesis in vivo. The four-week young BALB/c mice will be administrated with fipronil. The composition change in thymus and function of thymocytes will be evaluated. The influence of fipronil on the regulation of critical cytokine and chemokine network (e.g. IL-2, IL-7, SCF and receptors of IL-7, CCR4, and CCR7) and transcription factors (e.g. FoxN1, Lyl1, Aire, and Soxl3) of the thymopoiesis will be elucidated. SA2: To study the role of oxidative stress and apoptosis in fipronil-mediated immunotoxicity. Fipronil is known to increase oxidative stress in neural and liver cells. As T cells are sensitive to ROS, to clarify the role of ROS in fipronil-induced immunotoxic effects, such as cytokine production, apoptosis induction, will help to identify the effective antioxidants (e.g. vitamin C, N-acetyl-L-cysteine, superoxide dismutase and anti-inflammatory reagents) to alleviate its immunotoxicity. In addition, the influences of fipronil on intracellular signaling pathways associated with apoptosis will be measured.芬普尼免疫毒性胸腺發育氧化性傷害細胞凋亡轉錄因子調控介白素發育毒性T細胞fipronilimmunotoxicitythymopoiesisoxidative stressapoptosistranscription factorinterleukindevelopmental toxicityT cells