https://scholar.dgist.ac.kr/handle/20.500.11750/11719 Tue, 11 Aug 2026 10:16:57 GMT 2026-08-11T10:16:57Z https://scholar.dgist.ac.kr/handle/20.500.11750/60505 Title: Paraoxonase 2 as a target for aging-related diseases Author(s): Kim, Hyeong Hwan; Kang, Ye Jin; Lee, Jae Ho; Lee, Hyeong Min; Park, Hyung Soon; Nam, Chang-Hoon Abstract: Paraoxonase 2 (PON2) is an enzyme exhibiting both lactonase and esterase activities, widely distributed across various tissues and localized within cellular mitochondria. It plays a vital role in innate immunity by restricting bacterial infections and has diverse functions, including the regulation of mitochondrial reactive oxygen species levels and the management of endoplasmic reticulum stress. By alleviating oxidative stress, stabilizing mitochondria, and modulating apoptosis, PON2 emerges as a significant factor in the study of cellular senescence. This review consolidates recent findings regarding PON2's physiological roles, its mechanistic connections to senescence, and the therapeutic potential of modulating its activity. Our analysis highlights PON2's considerable promise as a target for aging-related diseases, including neurodegeneration, metabolic disorders, cardiovascular diseases, chronic inflammation, and cancer. Tue, 30 Jun 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60505 2026-06-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60337 Title: Proteomics and phosphoproteomics of human colorectal cancer cells lacking a specific kinase activity reveal kinase-specific compensatory responses Author(s): Han, Bitnara; Lim, Hyun Ji; Kim, Su-Jung; Shin, Jaejin; Kim, Hyeong Hwan; Kim, Kyun-Hwan; Nam, Chang-Hoon; Kim, Kwang Pyo Abstract: Cell signaling regulates cell proliferation, survival, and migration, and abnormal kinase activity is often implicated in cancer. Although kinases are key targets for anticancer therapy, drug-induced compensatory signaling and pathway rewiring often drive acquired resistance. These compensatory responses enable tumor cells to maintain proliferation and survival, contributing to acquired drug resistance. In this study, we investigated adaptive responses following the knockout of four specific kinase genes, ERK2, PLK1, PIK3CA, and PAK4, using HCT-116, a human colorectal cancer cell line. Using CRISPR-Cas9, we generated individual knockout cell lines and conducted quantitative proteomic and phosphoproteomic profiling using isobaric tagging and tandem mass tag (TMTs) to evaluate alterations in the signaling landscape. Our integrated analysis quantified 7,531 proteins and 10,877 phosphopeptides, revealing kinase-specific patterns of compensatory signaling. ERK2 knockout was associated with activation of MAPK- and PI3K/AKT-related kinases, whereas PIK3CA knockout induced extensive proteomic remodeling and engagement of pro-survival phosphorylation programs, illustrating distinct modes of signaling network rewiring. Integration of kinase-substrate enrichment analysis (KSEA) with global proteomic data revealed that adaptive kinase activity was largely uncoupled from protein abundance and uncovered a synthetic lethal interaction between ERK2 loss and RPS6KB1 inhibition. Collectively, these findings elucidate how targeted kinase loss drives homeostatic signaling networks in cancer cells. By systemically characterizing cellular-level signaling changes and contextualizing them within known kinase pathways, our results provide insights into synthetic lethality and identify potential therapeutic targets to counteract adaptive resistance to kinase inhibitors. Sat, 31 Jan 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60337 2026-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59989 Title: Hydrogen Evolution via Oxygen Tolerant [NiFe]-Hydrogenase Immobilized on TiO2 Nanotubes Author(s): Kim, Hwapyong; Kim, Ki Nam; Lee, Sang-Hyeon; Nam, Chang-Hoon; Lee, Young-Sam; In, Su-Il Abstract: [FeFe]-hydrogenase has been of great interest due to its high enzymatic activity for hydrogen evolution reactions (HERs). However, the big challenge of [FeFe]-hydrogenase is a significant performance degradation in aerobic conditions. On the other hand, [NiFe]-hydrogenase of E. coli has an oxygen tolerant property. Therefore, using [NiFe]-hydrogenase is an effective solution to avoid performance degradation in aerobic conditions. Herein, we extracted [NiFe]-hydrogenases from E. coli and immobilized them on the TiO2 nanotube (TNT) electrode prepared by pyrrole-based electropolymerization for application in aerobic conditions. As a result, we can confirm that [NiFe]-hydrogenases coated TNT electrode demonstrates the increased HER activity underaerobic condition than control samples in in-vitro activity test using methylene viologen and linear sweep voltammetry. Wed, 31 Dec 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59989 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59369 Title: Targeting PON2 with Vutiglabridin Restores Mitochondrial Integrity and Attenuates Oxidative Stress-Induced Senescence Author(s): Heo, Jin-Woong; Kim, Hyeong Hwan; Lee, Jae Ho; Lee, Hyeong Min; Park, Hyung Soon; Nam, Chang-Hoon Abstract: Oxidative stress-induced mitochondrial dysfunction has been identified as a central driver of cellular senescence and age-related degeneration. The present study investigated the potential of vutiglabridin, a paraoxonase 2 (PON2) agonist, to mitigate reactive oxygen species (ROS)-induced senescence in human LO2 hepatocytes. The process of senescence was induced by the administration of hydrogen peroxide, followed by the recovery of the cells in fresh medium. The levels of intracellular ROS, the senescence-associated β-galactosidase staining, the p16/p21 expression, and the mitochondrial morphology were the focus of a comprehensive assessment utilizing a range of analytical techniques, including microscopy, quantitative PCR, and Western blotting. The present study demonstrated that the administration of vutiglabridin resulted in a dose-dependent reduction in attenuation of the expression of senescence markers. Transmission electron microscopy (TEM) and stimulated emission depletion (STED) imaging revealed the preservation of mitochondrial structure and network connectivity in cells treated with vutiglabridin. These effects were absent in PON2 knockout cells, confirming that vutiglabridin’s action requires functional PON2. The present study demonstrates that vutiglabridin alleviates oxidative stress-induced cellular senescence by preserving mitochondrial integrity and redox balance via a PON2-dependent mechanism. This study lends further support to the investigation of the PON2 pathway as a therapeutic target in age-related cellular dysfunction. Fri, 31 Oct 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59369 2025-10-31T15:00:00Z