| 외안F-027 |
| 제2형 과립형 각막이상증(GCD2) 병리기전에서 소포체 스트레스의 역할 및 4-페닐부티르산의 GCD2 치료제로서의 가능성 |
| 연세대학교 의과대학 안과학교실 시기능연구센터, 각막이상증연구소
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| 이가영, 최문정, 박시윤, 지용우, 최승일, 김태임, 서경률, 김응권 |
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목적 : To date, no prevention or cure has been available for Granular corneal dystrophy type 2 (GCD2). Thus, the development of novel therapies is greatly anticipated. This study aimed to confirm whether ER stress is linked to GCD2 pathogenesis and whether the chemical chaperone, 4-phenylbutyric acid (4-PBA), could be exploited as a therapy for GCD2.
방법 : Wild-type (WT), heterozygous, and homozygous (HO) primary human corneal fibroblasts were prepared. Total RNA was isolated using and TRIzol reagent and cDNA synthesis and DNA amplification were performed. Flow cytometric analysis was performed and the samples were analyzed on a fluorescence-activated cell sorting (FACS) Calibur flow cytometer. Cell lysates from primary cultured corneal fibroblasts was prepared and western blotting were performed. To investigate the roles of UPR activation on GCD2 cell phenotype, cells were treated with the ER stress inducer tunicamycin for 48 hours.
결과 : Western blot analysis showed a significant upregulation of the ER chaperone BiP and foldase protein disulfide isomerase (PDI), indicating ER stress response activation in GCD2. Cell death was increased about 20-fold in GCD2 compared to WT cells treated with tunicamycin. 4-PBA treatment significantly attenuated tunicamycin-mediated BiP induction and reduced the levels of TGFBIp. TGFBIp levels were significantly reduced under ER stress and this reduction was considerably suppressed by the ubiquitin proteasome inhibitor MG132, indicating TGFBIp degradation via the ERAD pathway.
결론 : GCD2 cells were found to be more susceptible to ER stress induced cell death than were wild-type corneal fibroblasts. Treatment with 4-PBA not only protected against the GCD2 cell death induced by ER stress but also significantly suppressed the MG132-mediated increase in TGFBIp levels under ER stress. Together, these results suggest that ER stress might comprise an important factor in GCD2 pathophysiology and that the effects of 4-PBA treatment might have important implications for the development of GCD2 therapeutics.
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