Publications by authors named "Ok-Kyung Yoo"

KELCH-ECH-associated protein 1 (KEAP1) is an adaptor protein of Cullin 3 (CUL3) E3 ubiquitin ligase that targets a redox sensitive transcription factor, NF-E2-related factor 2 (NRF2). BRCA1-associated protein 1 (BAP1) is a tumor suppressor and deubiquitinase whose mutations increase the risk of several types of familial cancers. In the present study, we have identified that BAP1 deubiquitinates KEAP1 by binding to the BTB domain.

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The skin is constantly exposed to various types of chemical stresses that challenge the immune cells, leading to the activation of T cell-mediated hypersensitivity reactions including atopic dermatitis. Previous studies have demonstrated that a variety of natural compounds are effective against development of atopic dermatitis by modulating immune responses. Cardamonin is a natural compound abundantly found in cardamom spices and many other medicinal plant species.

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NF-E2-related factor 2 (NRF2) is a master regulator of redox homeostasis and provides cellular protection against oxidants and electrophiles by inducing the expression of a wide array of phase II cytoprotective genes. Until now, a number of NRF2 activators have been developed for treatment of chronic diseases and some are under evaluation in the clinical studies. On the other hand, accumulating evidence indicates that NRF2 confers chemoresistance and radioresistance, and its expression is correlated with poor prognosis in cancer patients.

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Homoharringtonine, known as omacetaxine mepesuccinate, is a pharmaceutical drug substance approved for treatment of chronic myeloid leukemia. Here, we report that homoharringtonine (HHT) is a novel chemical inhibitor of NRF2. HHT significantly suppressed NRF2 and ARE-dependent gene expression in human lung carcinoma A549 cells.

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We attempted to examine anti-inflammatory and anti-oxidant effects of 4'-O-β-D-glucosyl-5-O-methylvisamminol (GOMV), the first epigenetic inhibitor of histone phosphorylation at Ser10. While GOMV did not affect the viability of murine macrophage RAW 264.7 cells, it significantly suppressed lipopolysaccharide (LPS)-induced generation of prostaglandin E (PGE) and nitric oxide (NO) through transcriptional inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS).

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NF-E2-related factor 2 (NRF2) regulates transcription of phase II cytoprotective enzymes to protect normal cells against oxidative stress. However, a high level of NRF2 offers a growth advantage, chemoresistance, and radioresistance in cancer. In the present study, we have identified convallatoxin as a novel inhibitor of NRF2/ARE.

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Heme oxygenase-1 (HO-1) catalyzes the enzymatic degradation of heme to produce three anti-oxidant molecules: carbon monoxide (CO), ferrous ion (Fe), and biliverdin. Induction of HO-1 is currently considered as a feasible strategy to treat oxidative stress-related diseases. In the present study, we identified marliolide as a novel inducer of HO-1 in human normal keratinocyte HaCaT cells.

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Unlabelled: Keratinocytes are constantly exposed to extracellular insults, such as ultraviolet B, toxic chemicals and mechanical stress, all of which can facilitate the aging of keratinocytes via the generation of intracellular reactive oxygen species (ROS). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a critical role in protecting keratinocytes against oxidants and xenobiotics by binding to the antioxidant response element (ARE), a cis-acting element existing in the promoter of most phase II cytoprotective genes. In the present study, we have attempted to find novel ethanol extract(s) of indigenous plants of Jeju island, Korea that can activate the Nrf2/ARE-dependent gene expression in human keratinocyte HaCaT cells.

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