| Summary: | 碩士 === 國立臺灣大學 === 臨床醫學研究所 === 107 === Objective:
The development of Graves’ ophthalmopathy (GO) is associated with autoimmune dysfunction. Recent findings in GO indicate that IL-17A, inflammasome and related cytokines may also be involved in the autoimmunity of GO. We sought to investigate the pathogenic functions of IL-17A and NLRP3 inflammasome in GO.
Methods:
Orbital fat specimens were collected from 30 GO patients and 30 Non-GO controls. Immunohistochemical staining of orbital fat tissues and cell cultures of orbital fibroblasts were conducted in GO and Non-GO groups. Then, IL-17A was added to the fibroblast cultures, and cytokine expression, signaling pathways, and inflammasome mechanism were investigated using real-time RT-PCR, ELISA, Western blot, and small interfering RNA (siRNA).
Results:
Immunohistochemical staining of orbital fat specimen showed more expression of NLRP3 in orbital tissue of GO, compared with normal subjects. Interleukin-17A upregulated the mRNA levels of pro-IL-1β and the protein level of IL-1β in GO group. Furthermore, IL-17A was validated to enhance caspase-1 and NLRP3 protein expression in orbital fibroblasts, suggesting NLRP3 inflammasome activation. Inhibiting caspase-1 activity could also decrease IL-1β secretion. When siRNA transfected the orbital fibroblasts, NLRP3 expression was knockdown significantly and IL-17A-mediated pro-IL-1β mRNA release was also downregulated.
Conclusions:
Our observations illustrate that IL-17A could promote IL-1β production from orbital fibroblasts via the NLRP3 inflammasome in Graves’ ophthalmopathy, and subsequent cytokines may induce more inflammation and autoimmunity. This gives us the clues to target therapeutic potential for GO in the future.
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