A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals

The ubiquitin-proteasome system (UPS) is a major proteolytic pathway that safeguards protein homeostasis. The main 26S proteasome consists of a 20S catalytic core proteasome and a 19S substrate recognition proteasome. UPS dysfunction underlies many important clinical diseases involving inflammation,...

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Main Authors: Xue-Hua Ling, Shang-Kwei Wang, Yun-Hsuan Huang, Min-Jay Huang, Chang-Yih Duh
Format: Article
Language:English
Published: MDPI AG 2018-10-01
Series:Marine Drugs
Subjects:
Online Access:http://www.mdpi.com/1660-3397/16/10/395
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author Xue-Hua Ling
Shang-Kwei Wang
Yun-Hsuan Huang
Min-Jay Huang
Chang-Yih Duh
author_facet Xue-Hua Ling
Shang-Kwei Wang
Yun-Hsuan Huang
Min-Jay Huang
Chang-Yih Duh
author_sort Xue-Hua Ling
collection DOAJ
description The ubiquitin-proteasome system (UPS) is a major proteolytic pathway that safeguards protein homeostasis. The main 26S proteasome consists of a 20S catalytic core proteasome and a 19S substrate recognition proteasome. UPS dysfunction underlies many important clinical diseases involving inflammation, tumors, and neurodegeneration. Currently, three 20S proteasome inhibitors, bortezomib, carfilzomib, and ixazomib, have been approved for the treatment of multiple myeloma. We aim to screen UPS inhibitors for biomedical purposes. The protein interaction network of human cytomegalovirus UL76 targets UPS, resulting in aggregations of ubiquitinated proteins termed aggresomes. In this study, we demonstrated that cell-based high-content measurements of EGFP-UL76 aggresomes responded to bortezomib and MG132 treatment in a dose-dependent manner. Employing this high-content screening (HCS) assay, we screened natural compounds purified from Formosan soft corals. Four cembrane-based compounds, sarcophytonin A (1), sarcophytoxide (2), sarcophine (3), and laevigatol A (4), were found to enhance the high-content profiles of EGFP-UL76 aggresomes with relative ratios of 0.2. By comparison to the mechanistic action of proteasome inhibitors, compounds 1 and 3 modulated the accumulation of ubiquitinated proteins, with a unique pattern likely targeting 19S proteasome. We confirmed that the EGFP-UL76 aggresome-based HCS system greatly improves the efficacy and sensitivity of the identification of proteasome inhibitors.
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spelling doaj.art-ab7cf534d8154f8f9e597cd45abd998e2022-12-22T04:21:16ZengMDPI AGMarine Drugs1660-33972018-10-01161039510.3390/md16100395md16100395A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft CoralsXue-Hua Ling0Shang-Kwei Wang1Yun-Hsuan Huang2Min-Jay Huang3Chang-Yih Duh4Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 80441, TaiwanDepartment of Microbiology and Immunology, Kaohsiung Medical University, Kaohsiung 80708, TaiwanDepartment of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 80441, TaiwanDepartment of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 80441, TaiwanDepartment of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 80441, TaiwanThe ubiquitin-proteasome system (UPS) is a major proteolytic pathway that safeguards protein homeostasis. The main 26S proteasome consists of a 20S catalytic core proteasome and a 19S substrate recognition proteasome. UPS dysfunction underlies many important clinical diseases involving inflammation, tumors, and neurodegeneration. Currently, three 20S proteasome inhibitors, bortezomib, carfilzomib, and ixazomib, have been approved for the treatment of multiple myeloma. We aim to screen UPS inhibitors for biomedical purposes. The protein interaction network of human cytomegalovirus UL76 targets UPS, resulting in aggregations of ubiquitinated proteins termed aggresomes. In this study, we demonstrated that cell-based high-content measurements of EGFP-UL76 aggresomes responded to bortezomib and MG132 treatment in a dose-dependent manner. Employing this high-content screening (HCS) assay, we screened natural compounds purified from Formosan soft corals. Four cembrane-based compounds, sarcophytonin A (1), sarcophytoxide (2), sarcophine (3), and laevigatol A (4), were found to enhance the high-content profiles of EGFP-UL76 aggresomes with relative ratios of 0.2. By comparison to the mechanistic action of proteasome inhibitors, compounds 1 and 3 modulated the accumulation of ubiquitinated proteins, with a unique pattern likely targeting 19S proteasome. We confirmed that the EGFP-UL76 aggresome-based HCS system greatly improves the efficacy and sensitivity of the identification of proteasome inhibitors.http://www.mdpi.com/1660-3397/16/10/395proteasome inhibitorsoft coralhigh-content screeningcembrane
spellingShingle Xue-Hua Ling
Shang-Kwei Wang
Yun-Hsuan Huang
Min-Jay Huang
Chang-Yih Duh
A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
Marine Drugs
proteasome inhibitor
soft coral
high-content screening
cembrane
title A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
title_full A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
title_fullStr A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
title_full_unstemmed A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
title_short A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals
title_sort high content screening assay for the discovery of novel proteasome inhibitors from formosan soft corals
topic proteasome inhibitor
soft coral
high-content screening
cembrane
url http://www.mdpi.com/1660-3397/16/10/395
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