Dae-Geun Song

Dr. Dae-Geun Song

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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24 September 2018 in Journal of Clinical Investigation
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SNSeo Hee Nam
Seo Hee Nam
DKDoyeun Kim
Doyeun Kim
DLDoohyung Lee
Doohyung Lee
Hye-Mi LeeHye-Mi Lee
Hye-Mi Lee
DSDae-Geun Song
Dae-Geun Song
JLJung Weon Weon Lee
Jung Weon Weon Lee
Lysyl-tRNA synthetase (KRS) functions canonically in cytosolic translational processes. However, KRS is highly expressed in colon cancer, and localizes to distinct cellular compartments upon phosphorylations (i.e., the plasma membranes after T52 phosphorylation and the nucleus after S207 phosphorylation), leading to probably alternative noncanonical functions. It is unknown how other subcellular KRSs crosstalk with environmental cues during cancer progression. Here, we demonstrate that the KRS-dependent metastatic behavior of colon cancer spheroids within 3D gels requires communication between cellular molecules and extracellular soluble factors and neighboring cells. Membranous KRS and nuclear KRS were found to participate in invasive cell dissemination of colon cancer spheroids in 3D gels. Cancer spheroids secreted GAS6 via a KRS-dependent mechanism and caused the M2 polarization of macrophages, which activated the neighboring cells via secretion of FGF2/GROα/M-CSF to promote cancer dissemination under environmental remodeling via fibroblast-mediated laminin production. Analyses of tissues from clinical colon cancer patients and Krs–/+ animal models for cancer metastasis supported the roles of KRS, GAS6, and M2 macrophages in KRS-dependent positive feedback between tumors and environmental factors. Altogether, KRS in colon cancer cells remodels the microenvironment to promote metastasis, which can thus be therapeutically targeted at these bidirectional KRS-dependent communications of cancer spheroids with environmental cues.

29 March 2021 in Frontiers in Microbiology
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Noel GahamanyiNoel Gahamanyi
Noel Gahamanyi
DSDae-Geun Song
Dae-Geun Song
KYKye-Yoon Yoon
Kye-Yoon Yoon
LMLeonard MBOERA
Leonard MBOERA
MMMecky Matee
Mecky Matee
CPCheol-Ho Pan
Cheol-Ho Pan
ThermophilicCampylobacterspecies are among the major etiologies of bacterial enteritis globally. This study aimed at assessing the antimicrobial resistance (AMR) profiles, virulence genes, and genetic diversity of thermophilicCampylobacterspecies isolated from a layer poultry farm in South Korea. One hundred fifty-three chicken feces were collected from two layer poultry farms in Gangneung, South Korea. TheCampylobacterspecies were isolated by cultural techniques, while PCR and sequencing were used for species confirmation. Antimicrobial susceptibility testing for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)] was carried out by broth microdilution. Three AMR and nine virulence genes were screened by PCR. Genotyping was performed byflaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Of the 153 samples,Campylobacterspp. were detected in 55 (35.9%), withCampylobacter jejuniandCampylobacter colibeing 49 (89.1%) and six (10.9%), respectively. High-level resistance was observed for CIP (100%), NAL (100%), and TET (C. jejuni, 93.9%;C. coli: 83.3%). No resistance was observed for SIT. The missense mutation (C257T) ingyrA gene was confirmed by sequencing, while thetet(O) gene was similar to known sequences in GenBank. The rate of multidrug-resistant (MDR) strains was 8.2%, and they all belonged toC. jejuni. AllCampylobacterisolates possessed five virulence genes (cdtB,cstII,flaA,cadF, anddnaJ), but none possessedggt, while the rates for other genes (csrA,ciaB, andpldA) ranged between 33.3 and 95.9%. TheflaA-RFLP yielded 26flaA types (C. jejuni: 21 andC. coli: five), while the MLST showed 10 sequence types (STs) forC. jejuniand three STs forC. coli, with CC-607 (STs 3611) and CC-460 (ST-460) being predominant. Among the 10 STs ofC. jejuni, three were newly assigned. The findings of this study highlight the increased resistance to quinolones and TET, the virulence potential, and the diverse genotypes amongCampylobacterstrains isolated from the layer poultry farm.

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JWJessica Winarto
Jessica Winarto
DSDae-Geun Song
Dae-Geun Song
CPCheol-Ho Pan
Cheol-Ho Pan
Chronic liver disease (CLD) has emerged as a leading cause of human deaths. It caused 1.32 million deaths in 2017, which affected men more than women by a two-to-one ratio. There are various causes of CLD, including obesity, excessive alcohol consumption, and viral infection. Among them, non-alcoholic fatty liver disease (NAFLD), one of obesity-induced liver diseases, is the major cause, representing the cause of more than 50% of cases. Fucoxanthin, a carotenoid mainly found in brown seaweed, exhibits various biological activities against NAFLD. Its role in NAFLD appears in several mechanisms, such as inducing thermogenesis in mitochondrial homeostasis, altering lipid metabolism, and promoting anti-inflammatory and anti-oxidant activities. The corresponding altered signaling pathways are the β3-adorenarine receptor (β3Ad), proliferator-activated receptor gamma coactivator (PGC-1), adenosine monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor (PPAR), sterol regulatory element binding protein (SREBP), nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), SMAD2/3, and P13K/Akt pathways. Fucoxanthin also exhibits anti-fibrogenic activity that prevents non-alcoholic steatohepatitis (NASH) development.

22 December 2023 in Cancer Communications
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Journal Article
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JKJi Eon Kim
Ji Eon Kim
SPSo‐Young Park
So‐Young Park
CKChulhwan Kwak
Chulhwan Kwak
YLYOONJI LEE
YOONJI LEE
DSDae-Geun Song
Dae-Geun Song
JLJung Weon Weon Lee
Jung Weon Weon Lee
Background: Transmembrane 4 L six family member 5 (TM4SF5) translocates subcellularly and functions metabolically, although it is unclear how intracellular TM4SF5 translocation is linked to metabolic contexts. It is thus of interests to understand how the traffic dynamics of TM4SF5 to subcellular endosomal membranes are correlated to regulatory roles of metabolisms. Methods: Here, we explored the metabolic significance of TM4SF5 localization at mitochondria‐lysosome contact sites (MLCSs), using in vitro cells and in vivo animal systems, via approaches by immunofluorescence, proximity labelling based proteomics analysis, organelle reconstitution etc. Results: Upon extracellular glucose repletion following depletion, TM4SF5 became enriched at MLCSs via an interaction between mitochondrial FK506‐binding protein 8 (FKBP8) and lysosomal TM4SF5. Proximity labeling showed molecular clustering of phospho‐dynamic‐related protein I (DRP1) and certain mitophagy receptors at TM4SF5‐enriched MLCSs, leading to mitochondrial fission and autophagy. TM4SF5 bound NPC intracellular cholesterol transporter 1 (NPC1) and free cholesterol, and mediated export of lysosomal cholesterol to mitochondria, leading to impaired oxidative phosphorylation but intact tricarboxylic acid (TCA) cycle and β‐oxidation. In mouse models, hepatocyte Tm4sf5 promoted mitophagy and cholesterol transport to mitochondria, both with positive relations to liver malignancy. Conclusions: Our findings suggested that TM4SF5‐enriched MLCSs regulate glucose catabolism by facilitating cholesterol export for mitochondrial reprogramming, presumably while hepatocellular carcinogenesis, recapitulating aspects for hepatocellular carcinoma metabolism with mitochondrial reprogramming to support biomolecule synthesis in addition to glycolytic energetics.

18 February 2024 in Marine Drugs
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Journal Article
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QTQuyen To Truong
Quyen To Truong
YPYun JI Park
Yun JI Park
JWJessica Winarto
Jessica Winarto
PHPhuong Kim Huynh
Phuong Kim Huynh
JMJinyoung Moon
Jinyoung Moon
Sang Min KimSang Min Kim
Sang Min Kim
This study aimed to investigate the regulation of fucoxanthin (FX) biosynthesis under various nitrogen conditions to optimize FX productivity in Phaeodactylum tricornutum. Apart from light, nitrogen availability significantly affects the FX production of microalgae; however, the underlying mechanism remains unclear. In batch culture, P. tricornutum was cultivated with normal (NN, 0.882 mM sodium nitrate), limited (LN, 0.22 mM), and high (HN, 8.82 mM) initial nitrogen concentrations in f/2 medium. Microalgal growth and photosynthetic pigment production were examined, and day 5 samples were subjected to fucoxanthin–chlorophyll a/c-binding protein (FCP) proteomic and transcriptomic analyses. The result demonstrated that HN promoted FX productivity by extending the exponential growth phase for higher biomass and FX accumulation stage (P1), showing a continuous increase in FX accumulation on day 6. Augmented FX biosynthesis via the upregulation of carotenogenesis could be primarily attributed to enhanced FCP formation in the thylakoid membrane. Key proteins, such as LHC3/4, LHCF8, LHCF5, and LHCF10, and key genes, such as PtPSY, PtPDS, and PtVDE, were upregulated under nitrogen repletion. Finally, the combination of low light and HN prolonged the P1 stage to day 10, resulting in maximal FX productivity to 9.82 ± 0.56 mg/L/day, demonstrating an effective strategy for enhancing FX production in microalgae cultivation.

9 November 2020 in Antibiotics
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Noel GahamanyiNoel Gahamanyi
Noel Gahamanyi
DSDae-Geun Song
Dae-Geun Song
KCKwang Hyun Cha
Kwang Hyun Cha
KYKYE-YOON YOON
KYE-YOON YOON
LMLeonard MBOERA
Leonard MBOERA
CPCheol-Ho Pan
Cheol-Ho Pan
Campylobacter species have developed resistance to existing antibiotics. The development of alternative therapies is, therefore, a necessity. This study evaluates the susceptibility of Campylobacter strains to selected natural products (NPs) and frontline antibiotics. Two C. jejuni strains (ATCC® 33560TM and MT947450) and two C. coli strains (ATCC® 33559TM and MT947451) were used. The antimicrobial potential of the NPs, including plant extracts, essential oils, and pure phytochemicals, was evaluated by broth microdilution. The growth was measured by spectrophotometry and iodonitrotetrazolium chloride. Antibiotic resistance genes (tet(O) and gyrA) were characterized at the molecular level. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) ranged from 25 to 1600 µg/mL. Cinnamon oil, (E)-Cinnamaldehyde, clove oil, eugenol, and baicalein had the lowest MIC and MBC values (25–100 µg/mL). MT947450 and MT947451 were sensitive to erythromycin and gentamicin but resistant to quinolones and tetracycline. Mutations in gyrA and tet(O) genes from resistant strains were confirmed by sequencing. The findings show that NPs are effective against drug-sensitive and drug-resistant Campylobacter strains. The resistance to antibiotics was confirmed at phenotypic and genotypic levels. This merits further studies to decipher the action mechanisms and synergistic activities of NPs.