[환경] Analysis of polychlorinated biphenyls in shellfish collected from a market

Ga-Jeong Lee,Ji Yong Moon,Eun-Hwa Lee,Hye-Sook Ha,Gi Ho Jeong 한국분석과학회 2005 분석과학 Vol.18 No.6

MEKs/ERKs-mediated FBXO1/E2Fs interaction interference modulates G1/S cell cycle transition and cancer cell proliferation

Ga-Eun Lee,Dohyun Jeung,Weidong Chen,Jiin Byun,Joo Young Lee,Han Chang Kang,Hye Suk Lee,Dae Joon Kim,Jin-Sung Choi,Cheol-Jung Lee,Hyun-Jung An,Yong-Yeon Cho 대한약학회 2023 Archives of Pharmacal Research Vol.46 No.1

E2F 1, 2, and 3a, (refer to as E2Fs) are a subfamily of E2F transcription factor family that play essential roles in cell-cycle progression, DNA replication, DNA repair, apoptosis, and differentiation. Although the transcriptional regulation of E2Fs has focused on pocket protein retinoblastoma protein complex, recent studies indicate that post-translational modification and stability regulation of E2Fs play key roles in diverse cellular processes. In this study, we found that FBXO1, a component of S-phase kinase-associated protein 1 (SKP1)-cullin 1-F-box protein (SCF) complex, is an E2Fs binding partner. Furthermore, FBXO1 to E2Fs binding induced K48 ubiquitination and subsequent proteasomal degradation of E2Fs. Binding domain analysis indicated that the Arg (R)/Ile (I) and R/Val (V) motifs, which are located in the dimerization domain of E2Fs, of E2F 1 and 3a and E2F2, respectively, acted as degron motifs (DMs) for FBXO1. Notably, RI/AA or RV/AA mutation in the DMs reduced FBXO1-mediated ubiquitination and prolonged the half-lives of E2Fs. Importantly, the stabilities of E2Fs were affected by phosphorylation of threonine residues located near RI and RV residues of DMs. Phosphorylation prediction database analysis and specific inhibitor analysis revealed that MEK/ERK signaling molecules play key roles in FBXO1/E2Fs’ interaction and modulate E2F protein turnover. Moreover, both elevated E2Fs protein levels by knockdown of FBXO1 and decreased E2Fs protein levels by sh-E2F3a delayed G1/S cell cycle transition, resulting in inhibition of cancer cell proliferation. These results demonstrated that FBXO1-E2Fs axis-mediated precise E2Fs stability regulation plays a key role in cell proliferation via G1/S cell cycle transition.

Unusual CD4 ⁺ CD28 ⁻ T Cells and Their Pathogenic Role in Chronic Inflammatory Disorders

Lee, Ga Hye,Lee, Won-Woo 한국조명·전기설비학회 2016 한국조명·전기설비학회 학술대회논문집 Vol. No.

<P>CD28 is a primary co-stimulatory receptor that is essential for successful T cell activation, proliferation, and survival. While ubiquitously expressed on naive T cells, the level of CD28 expression on memory T cells is largely dependent on the T-cell differentiation stage in humans. Expansion of circulating T cells lacking CD28 was originally considered a hallmark of age-associated immunological changes in humans, with a progressive loss of CD28 following replicative senescence with advancing age. However, an increasing body of evidence has revealed that there is a significant age-inappropriate expansion of CD4<SUP>+</SUP>CD28<SUP>−</SUP> T cells in patients with a variety of chronic inflammatory diseases, suggesting that these cells play a role in their pathogenesis. In fact, expanded CD4<SUP>+</SUP>CD28<SUP>−</SUP> T cells can produce large amounts of proinflammatory cytokines such as IFN-γ and TNF-α and also have cytotoxic potential, which may cause tissue damage and development of pathogenesis in many inflammatory disorders. Here we review the characteristics of CD4<SUP>+</SUP>CD28<SUP>−</SUP> T cells as well as the recent advances highlighting the contribution of these cells to several disease conditions.</P>

Effect of Polar Amino Acid Residue Substitution by Site-Directed Mutagenesis in the N-terminal Domain of Pseudomonas sp. Phytase on Enzyme Activity

( Ga Hye Lee ),( Won Je Jang ),( Soyeong Kim ),( Yoonha Kim ),( In-soo Kong ) 한국미생물 · 생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.7

The N-terminal domain of the Pseudomonas sp. FB15 phytase increases low-temperature activity and catalytic efficiency. In this study, the 3D structure of the N-terminal domain was predicted and substitutions for the amino acid residues of the region assumed to be the active site were made. The activity of mutants, in which alanine (A) was substituted for the original residue, was investigated at various temperatures and pH values. Significant differences in enzymatic activity were observed only in mutant E263A, suggesting that the amino acid residue at position 263 of the N-terminal domain is important in enzyme activity.

Dysregulated CREB3 cleavage at the nuclear membrane induces karyoptosis-mediated cell death

Lee Ga-Eun,Bang Geul,Byun Jiin,Lee Cheol-Jung,Chen Weidong,Jeung Dohyun,An Hyun-Jung,Kang Han Chang,Lee Joo Young,Lee Hye Suk,Hong Young-Soo,Kim Dae Joon,Keniry Megan,Kim Jin Young,Choi Jin-Sung,Fanto 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

Cancer cells often exhibit resistance to apoptotic cell death, but they may be vulnerable to other types of cell death. Elucidating additional mechanisms that govern cancer cell death is crucial for developing new therapies. Our research identified cyclic AMP-responsive element-binding protein 3 (CREB3) as a crucial regulator and initiator of a unique cell death mechanism known as karyoptosis. This process is characterized by nuclear shrinkage, deformation, and the loss of nuclear components following nuclear membrane rupture. We found that the N-terminal domain (aa 1-230) of full-length CREB3 (CREB3-FL), which is anchored to the nuclear inner membrane (INM), interacts with lamins and chromatin DNA. This interaction maintains a balance between the outward force exerted by tightly packed DNA and the inward constraining force, thereby preserving INM integrity. Under endoplasmic reticulum (ER) stress, aberrant cleavage of CREB3-FL at the INM leads to abnormal accumulation of the cleaved form of CREB3 (CREB3-CF). This accumulation disrupts the attachment of CREB3-FL to the INM, resulting in sudden rupture of the nuclear membrane and the onset of karyoptosis. Proteomic studies revealed that CREB3-CF overexpression induces a DNA damage response akin to that caused by UVB irradiation, which is associated with cellular senescence in cancer cells. These findings demonstrated that the dysregulation of CREB3-FL cleavage is a key factor in karyoptotic cell death. Consequently, these findings suggest new therapeutic strategies in cancer treatment that exploit the process of karyoptosis.

The Affected Factors on the Health Status of Middle-aged Male Workers

Ga Eon Lee,Yeon Hyang Lee,Hye Jung Jun 한국간호과학회 2019 한국간호과학회 학술대회 Vol.2019 No.10

FBXW7-mediated stability regulation of signal transducer and activator of transcription 2 in melanoma formation

Lee, Cheol-Jung,An, Hyun-Jung,Kim, Seung-Min,Yoo, Sun-Mi,Park, Juhee,Lee, Ga-Eun,Kim, Woo-Young,Kim, Dae Joon,Kang, Han Chang,Lee, Joo Young,Lee, Hye Suk,Cho, Sung-Jun,Cho, Yong-Yeon National Academy of Sciences 2020 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.117 No.1

<P><B>Significance</B></P><P>The physiological relevance of STAT2 (a member of STAT family) in melanoma formation is clearly shown using a human skin tissue array. Moreover, FBXW7-mediated STAT2 protein stability regulation via ubiquitination is shown to play an essential role in melanoma cell proliferation in monolayer and anchorage-independent 3D culture systems. The molecular mechanisms that regulate STAT2 protein stability by FBXW7 include the interaction between CCD and DBD domains of STAT2 and the WD40 domain of FBXW7. STAT2 phosphorylation at the putative degron motifs that contain Ser381, Thr385, and Ser393 might be mediated by GSK3β. These serve as critical amino acids that form hydrogen bonds with the WD40 domain of FBXW7. Thus, the FBXW7–STAT2 signaling axis is an important target for melanoma treatment.</P><P>In this study, we provide critical evidence that STAT2 stability regulation plays an essential role in melanoma cell proliferation and colony growth. We found that the interaction of FBXW7 and STAT2 induced STAT2 destabilization via a ubiquitination-mediated proteasomal degradation pathway. Notably, GSK3β-mediated STAT2 phosphorylation facilitated STAT2–FBXW7 interactions via the DNA binding domain of STAT2 and domains 1, 2, 6, and 7 of FBXW7 WD40. Importantly, the inverse correlation between protein levels of STAT2 and FBXW7 were observed not only in human melanoma cells but also in a human skin cancer tissue array. The relationship between protein levels of STAT2 and FBXW7, cell proliferation, and colony growth were similarly observed in the melanoma cell lines SK-MEL-2, -5, and -28. Moreover, STAT2 knockdown in melanoma cells suppressed melanoma cell proliferation and colony formation. These data demonstrated that FBXW7-mediated STAT2 stability regulation plays an essential role in melanoma cell proliferation and cancer growth.</P>

Clinical Features and Risk Factors for Development of Breakthrough Gram-Negative Bacteremia during Carbapenem Therapy

Lee, Ji-Yong,Kang, Cheol-In,Ko, Jae-Hoon,Lee, Woo Joo,Seok, Hye-Ri,Park, Ga Eun,Cho, Sun Young,Ha, Young Eun,Chung, Doo Ryeon,Lee, Nam Yong,Peck, Kyong Ran,Song, Jae-Hoon American Society for Microbiology 2016 Antimicrobial Agents and Chemotherapy Vol.60 No.11

<B>ABSTRACT</B><P>With the increasing use of carbapenems, carbapenem-resistant Gram-negative bacteria have become a major concern in health care-associated infections. The present study was performed to evaluate the clinical and microbiological features of breakthrough Gram-negative bacteremia (GNB) during carbapenem therapy and to assess risk factors for development of breakthrough GNB. A case-control study was performed at a tertiary hospital from 2005 to 2014. Case patients were defined as individuals whose blood cultures grew Gram-negative bacteria while the patients were receiving carbapenems for at least 48 h before breakthrough GNB. Age-, sex-, and date-matched controls were selected from patients who received carbapenem for at least 48 h and did not develop breakthrough GNB during carbapenem treatment. A total of 101 cases of breakthrough GNB were identified and compared to 100 controls. The causative microorganisms for breakthrough GNB wereStenotrophomonas maltophilia(<I>n</I>= 33),Acinetobacter baumannii(<I>n</I>= 32),Pseudomonas aeruginosa(<I>n</I>= 21), and others (<I>n</I>= 15). Approximately 90% ofS. maltophiliaisolates were susceptible to levofloxacin and trimethoprim-sulfamethoxazole. The most common infection types were primary bacteremia (38.6%) and respiratory infections (35.6%). More than half of the patients died within a week after bacteremia, and the 30-day mortality rate was 70.3%. In a multivariate analysis, a longer hospital stay, hematologic malignancy, persistent neutropenia, immunosuppressant use, and previous colonization by causative microorganisms were significantly associated with breakthrough GNB. Our data suggest thatS. maltophilia,A. baumannii, andP. aeruginosaare the major pathogens of breakthrough GNB during carbapenem therapy, in association with a longer hospital stay, hematologic malignancy, persistent neutropenia, immunosuppressant use, and previous colonization.</P>

Anti-inflammatory mechanisms of suppressors of cytokine signaling target ROS via NRF-2/thioredoxin induction and inflammasome activation in macrophages

( Ga-young Kim ),( Hana Jeong ),( Hye-young Yoon ),( Hye-min Yoo ),( Jae Young Lee ),( Seok Hee Park ),( Choong-eun Lee ) 생화학분자생물학회 2020 BMB Reports Vol.53 No.12

Suppressors of cytokine signaling (SOCS) exhibit diverse antiinflammatory effects. Since ROS acts as a critical mediator of inflammation, we have investigated the anti-inflammatory mechanisms of SOCS via ROS regulation in monocytic/macrophagic cells. Using PMA-differentiated monocytic cell lines and primary BMDMs transduced with SOCS1 or shSOCS1, the LPS/TLR4- induced inflammatory signaling was investigated by analyzing the levels of intracellular ROS, antioxidant factors, inflammasome activation, and pro-inflammatory cytokines. The levels of LPS-induced ROS and the production of pro-inflammatory cytokines were notably down-regulated by SOCS1 and up-regulated by shSOCS1 in an NAC-sensitive manner. SOCS1 up-regulated an ROS-scavenging protein, thioredoxin, via enhanced expression and binding of NRF-2 to the thioredoxin promoter. SOCS3 exhibited similar effects on NRF-2/thioredoxin induction, and ROS downregulation, resulting in the suppression of inflammatory cytokines. Notably thioredoxin ablation promoted NLRP3 inflammasome activation and restored the SOCS1-mediated inhibition of ROS and cytokine synthesis induced by LPS. The results demonstrate that the anti-inflammatory mechanisms of SOCS1 and SOCS3 in macrophages are mediated via NRF-2-mediated thioredoxin upregulation resulting in the downregulation of ROS signal. Thus, our study supports the anti-oxidant role of SOCS1 and SOCS3 in the exquisite regulation of macrophage activation under oxidative stress. [BMB Reports 2020; 53(12): 640-645]

Elderly Patients Exhibit Stronger Inflammatory Responses during Gout Attacks

Lee, Jae Hyun,Yang, Ji Ae,Shin, Kichul,Lee, Ga Hye,Lee, Won-Woo,Lee, Eun Young,Song, Yeong Wook,Lee, Eun Bong,Park, Jin Kyun KOREAN ACADEMY OF MEDICAL SCIENCE 2017 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.32 No.12

<P>Gout attacks are often accompanied by systemic inflammatory response. The aim of the retrospective study was to compare gout patients in different age groups in terms of their clinical features at gout attacks. Patients, who were treated for gout attack in two tertiary medical centers between January 2000 and April 2014, were divided into young (≤ 50 years), middle-aged, and elderly (> 65 years) groups. Patients in three age groups were compared in terms of presence of fever (> 37.8°C), C-reactive protein (CRP) levels, and erythrocyte sedimentation ratio (ESR) at the gout attacks. Monocytes, which were isolated from 10 consecutive patients who previously experienced gout attacks, were stimulated with monosodium urate (MSU) crystals and cytokine production was measured by flow cytometry. Among 254 patients analyzed in this study, 48 were young, 65 were middle-aged, and 141 were elderly. The elderly patients were more likely to have fever (51.1%) during the attack than the young (20.8%) and middle-aged (30.8%) patients (<I>P</I> < 0.001 by χ<SUP>2</SUP> test). They were also more likely to have higher ESR and CRP levels than the young patients (<I>P</I> = 0.002 for ESR, <I>P</I> < 0.001 for CRP). Patients' age correlated significantly with CRP and ESR levels (both <I>P</I> < 0.001). After stimulation with MSU, the production of interleukin-1β by monocytes increased with patients' age (<I>r</I> = 0.670, <I>P</I> = 0.03). In conclusion, gout attacks in elderly patients are associated with fever and higher ESR and CRP levels, often resembling a septic arthritis.</P>