RAN LEE

Dr. RAN LEE

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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 February 2022 in Toxins
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RLRAN LEE
RAN LEE
DKDong-Wook Kim
Dong-Wook Kim
WLWon-Young Lee
Won-Young Lee
HPHyun Jung Park
Hyun Jung Park
Zearalenone (ZEN), a widely known mycotoxin, is mainly produced by various Fusarium species, and it is a potent estrogenic metabolite that affects reproductive health in livestock and humans. In this study, the molecular mechanisms of toxicity and cell damage induced by ZEN in GC-1 spermatogonia (spg) cells were evaluated. Our results showed that cell viability decreased and apoptosis increased in a dose-dependent manner when GC-1 spg cells were exposed to ZEN. In addition, the key proteins involved in apoptosis, cleaved caspase-3 and -8, BAD, BAX, and phosphorylation of p53 and ERK1/2, were significantly increased in ZEN-exposed GC-1 spg cells for 24 h, and cytochrome c was released from mitochondria by ZEN. Interestingly, ZEN also triggered autophagy in GC-1 spg cells. The expression levels of the autophagy-related genes Atg5, Atg3, Beclin 1, LC3, Ulk1, Bnip 3, and p62 were significantly higher in ZEN-treated GC-1 spg cells, and the protein levels of both LC3A/B and Atg12 were remarkably increased in a dose-dependent manner in ZEN-exposed GC-1 spg cells compared to the control. In addition, immunostaining results showed that ZEN-treated groups showed a remarkable increase in LC 3A/B positive puncta as compared to the control in a dose-dependent manner based on confocal microscopy analysis in GC-1 spg cells. Our findings suggest that ZEN has toxic effects on tGC-1 spg cells and induces both apoptosis and autophagy.

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HPHyun Jung Park
Hyun Jung Park
JKJi-Soo Kim
Ji-Soo Kim
RLRAN LEE
RAN LEE
Hyuk SongHyuk Song
Hyuk Song
Chemotherapy is used for childhood cancer but may lead to infertility in patients. Spermatogonia stem cells are present in the testes of prepubertal boys, although they do not produce sperm at this age. Herein, we evaluated the toxicity of cisplatin, a known medicine for cancer treatment, in neonatal mouse testes using in vitro organ culture. Mouse testicular fragments (MTFs) derived from 5.5-d postpartum mouse testes were exposed to 1–10 μg/mL cisplatin. The results showed that cisplatin significantly downregulated the expression of germ cell marker genes, including differentiated and undifferentiated, in a dose-dependent manner. In particular, a high dose of cisplatin (10 μg/mL) led to germ cell depletion. In addition, the expression levels of the Sertoli cell marker gene, the number of SOX9+ Sertoli cells, and the levels of SOX9 protein were markedly decreased in cisplatin-treated MTFs compared to controls. The mRNA expression of steroidogenic enzyme-related genes significantly increased in cisplatin-treated MTFs, except for estrogen receptor 1 (Esr1). Consistently, 3β-hydroxysteroid dehydrogenase protein was also observed in the interstitial regions of cisplatin-treated MTFs. Altogether, our findings showed a significant impairment in germ cell development, Sertoli cell survival, and steroidogenesis in the MTFs of cisplatin-treated mice.

21 April 2023 in Toxics
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WLWon-Young Lee
Won-Young Lee
RLRAN LEE
RAN LEE
HPHyun Jung Park
Hyun Jung Park
Tebuconazole (TEB) is a triazole fungicide used to increase crop production by controlling fungi, insects, and weeds. Despite their extensive use, people are concerned about the health risks associated with pesticides and fungicides. Numerous studies have defined the cellular toxicity of triazole groups in pesticides, but the mechanisms of TEB toxicity in bovine mammary gland epithelial cells (MAC-T cells) have not yet been studied. Damage to the mammary glands of dairy cows directly affects milk production. This study investigated the toxicological effects of TEB on MAC-T cells. We found that TEB decreases both cell viability and proliferation and activates apoptotic cell death via the upregulation of pro-apoptotic proteins, such as cleaved caspases 3 and 8 and BAX. TEB also induced endoplasmic reticulum (ER) stress via the upregulation of Bip/GRP78; PDI; ATF4; CHOP; and ERO1-Lα. We found that TEB induced mitochondria-mediated apoptotic MAC-T cell death by activating ER stress. This cell damage eventually led to a dramatic reduction in the expression levels of the milk-protein-synthesis-related genes LGB; LALA; CSN1S1; CSN1S2; and CSNK in MAC-T cells. Our data suggest that the exposure of dairy cows to TEB may negatively affect milk production by damaging the mammary glands.

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HSHyeon Woo Sim
Hyeon Woo Sim
WLWon-Young Lee
Won-Young Lee
RLRAN LEE
RAN LEE
SYSeo Young Yang
Seo Young Yang
YHYoun-Kyung Ham
Youn-Kyung Ham
HPHyun Jung Park
Hyun Jung Park
Brassica oleracea var. italica (broccoli), a member of the cabbage family, is abundant with many nutrients, including vitamins, potassium, fiber, minerals, and phytochemicals. Consequently, it has been used as a functional food additive to reduce oxidative stress and inflammatory responses. In the current study, the effects of sulforaphane-rich broccoli sprout extract (BSE) on the inflammatory response were investigated in vitro and in vivo. Comparative high-performance liquid chromatography analysis of sulforaphane content from different extracts revealed that 70% ethanolic BSE contained more sulforaphane than the other extracts. qPCR and enzyme immunoassay analyses revealed that BSE markedly reduced the expression of proinflammatory cytokines and mediators, including cyclooxygenase 2, interleukin (IL)-1β, IL-6, IL-1, inducible nitric oxide synthase (iNOS), and tumor necrosis factor-α (TNF-α), in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Pretreatment with BSE improved the survival rate and suppressed alanine aminotransferase and aspartate aminotransferase expression in LPS-induced endotoxemic mice, while proinflammatory cytokines such as IL-1β, TNF-α, IL-6, cyclooxygenase-2, and iNOS decreased dramatically in the LPS-induced liver injury model via BSE treatment. Additionally, F4/80 immunostaining showed that BSE suppressed hepatic macrophage infiltration in the liver after lipopolysaccharide injection. In conclusion, BSE may be a potential nutraceutical for preventing and regulating excessive immune responses in inflammatory disease.

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RLRAN LEE
RAN LEE
WLWon-Young Lee
Won-Young Lee
HPHyun Jung Park
Hyun Jung Park
Melatonin, a hormone secreted by the pineal gland of vertebrates, regulates sleep, blood pressure, and circadian and seasonal rhythms, and acts as an antioxidant and anti-inflammatory agent. We investigated the protective effects of melatonin against markers of D-galactose (D-Gal)-induced hepatocellular aging, including liver inflammation, hepatocyte structural damage, and non-alcoholic fatty liver. Mice were divided into four groups: phosphate-buffered saline (PBS, control), D-Gal (200 mg/kg/day), melatonin (20 mg/kg), and D-Gal (200 mg/kg) and melatonin (20 mg) cotreatment. The treatments were administered once daily for eight consecutive weeks. Melatonin treatment alleviated D-Gal-induced hepatocyte impairment. The AST level was significantly increased in the D-Gal-treated groups compared to that in the control group, while the ALT level was decreased compared to the melatonin and D-Gal cotreated group. Inflammatory genes, such as IL1-β, NF-κB, IL-6, TNFα, and iNOS, were significantly increased in the D-Gal aging model, whereas the expression levels of these genes were low in the D-Gal and melatonin cotreated group. Interestingly, the expression levels of hepatic steatosis-related genes, such as LXRα, C/EBPα, PPARα, ACC, ACOX1, and CPT-1, were markedly decreased in the D-Gal and melatonin cotreated group. These results suggest that melatonin suppresses hepatic steatosis and inflammation in a mouse model of D-Gal-induced aging.

Verified
Journal Article
Open access
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WLWon-Young Lee
Won-Young Lee
RLRAN LEE
RAN LEE
HPHyun Jung Park
Hyun Jung Park
The fungicide tebuconazole (TEB) poses risks to human and animal health via various exposure routes. It induces toxicity in multiple organs and disrupts reproductive health by affecting steroid hormone synthesis and fetal development. In this study, we investigated the impact of TEB on fetal testes using in vitro models, focusing on germ, Sertoli, and Leydig cells, and explored the mechanisms underlying cellular damage. The results revealed significant damage to germ cells and disruption of Leydig cell development. TEB exposure led to a decrease in germ cell numbers, as indicated by histological and immunostaining analyses. TEB induced the up- and down-regulation of the expression of fetal and adult Leydig cell markers, respectively. Additionally, TEB-treated fetal testes exhibited increased expression of oxidative-stress-related genes and proteins. However, co-treatment with the antioxidant N-acetylcysteine mitigated TEB-induced germ cell damage and prevented abnormal Leydig cell development. These findings suggest that administration of antioxidants can prevent the intratesticular damage typically caused by TEB exposure.