6.Kap1 Regulates Protein Stability of Nanog by Interfering with Fbxw8-Dependent Ubiquitination
Hye Ji MOON ; Nayeon LEE ; Bo Seok LEE ; Min Seok PARK ; Yoon Ji JUNG ; Ye Seul KIM ; Jae Ho KIM
International Journal of Stem Cells 2025;18(4):401-411
Nanog is a key transcription factor that regulates the self-renewal and pluripotency of embryonic stem cells (ESCs).Although Kap1 has been demonstrated to regulate the stability of stemness factors, including Oct4 and Lin28A, its role in regulating Nanog protein stability in ESCs remains unexplored. In the present study, we examined the interaction between Kap1 and Nanog and its role in stabilizing the Nanog protein. Immunoprecipitation assays revealed that Nanog specifically interacted with the coiled-coil domain of Kap1. Kap1 overexpression increased the stability of the Nanog protein by inhibiting its ubiquitination and proteasomal degradation, whereas Kap1 silencing accelerated Nanog degradation. Furthermore, Kap1 overexpression inhibits Nanog degradation by interfering with the binding of Nanog to Fbxw8, an E3 ubiquitin ligase that promotes Nanog degradation via a proteasome-dependent process. These results indicate that Kap1 acts as a key regulator to preserve ESC properties by modulating the protein stability of stemness factors, including Oct4, Lin28A, and Nanog.
7.Impact of anti-tumor necrosis factor treatment on lipid profiles in Korean patients with ankylosing spondylitis
Inbeom KWON ; Nayeon CHOI ; Ji Hui SHIN ; Seunghun LEE ; Bora NAM ; Tae-Hwan KIM
Journal of Rheumatic Diseases 2024;31(1):41-48
Objective:
To investigate the effects of anti-tumor necrosis factor (TNF) treatment on lipid profiles and identify risk factors for an increase in total cholesterol (TC) after the anti-TNF treatment in ankylosing spondylitis (AS) patients.
Methods:
This retrospective cohort study analyzed AS patients who received the first-line anti-TNF treatment. Patients with at least nine months of follow-up were included; those who were under 18 years or on any lipid-lowering agent were excluded. A linear mixed model was used to assess the impact of anti-TNF inhibitors on disease activity and lipid profile (TC, low-density lipoprotein [LDL], high-density lipoprotein [HDL], and triglycerides [TG]). Univariable and multivariable linear regression were used to identify risk factors for an increase in TC after 3 months of anti-TNF treatment.
Results:
A total of 315 AS patients were enrolled (78.1% male, median age 32.0 [26.0~41.0]). TC, HDL, and TG levels significantly increased particularly within the first 3 months of anti-TNF treatment, while LDL level did not show significant changes.Changes in inflammatory markers and lipid particles (TC, LDL, TG) were correlated over time, but HDL showed no significant correlation. Older age, higher baseline erythrocyte sedimentation rate, and lower baseline LDL level were related to an increase in TC after 3 months of the anti-TNF treatment.
Conclusion
In AS patients, anti-TNF treatment has been found to increase lipid particles, potentially due to its anti-inflammatory effects. Future research should explore the underlying mechanism and the clinical implications of dyslipidemia, particularly the occurrence of cardiovascular events, following anti-TNF treatment in AS patients.
8.Evaluation of Disinfection Efficacy in Flexible Laryngoscopy According to Cidex Ortho-Phthalaldehyde Immersion Time: A Multicenter Study
Young Chan LEE ; Hae Sang PARK ; Heejin KIM ; Nayeon CHOI ; Sang Hyuk LEE ; Sei Young LEE ; Kwang Jae CHO
Journal of the Korean Society of Laryngology Phoniatrics and Logopedics 2024;35(3):89-93
Background and Objectives:
Flexible laryngoscopes are indispensable tools in otolaryngology, but their frequent use makes them vulnerable to contamination, thus posing a risk of cross-infection. Unlike gastrointestinal endoscopes, flexible laryngoscopes currently lack standardized disinfection protocols. This study evaluates the efficacy of Cidex OPA (0.55% ortho-phthalaldehyde) to establish an effective, practical disinfection protocol for flexible laryngoscopes.Materials and Method This multicenter study involved the use of flexible laryngoscopes in otolaryngology outpatient clinics across five university hospitals. Laryngoscopes were immersed in Cidex OPA for 1, 5, or 12 minutes, with an additional group treated using Tristel wipes and foam after a 12-minute immersion. Swab samples were collected from the distal 15 cm of each laryngoscope following disinfection and cultured on blood agar plates under aerobic conditions at 35°C–37°C with 5% CO2 for 72 hours. Positive controls included laryngoscopes directly contaminated with saliva or laryngeal secretions.
Results:
Six out of ten positive control samples demonstrated bacterial growth. However, no bacterial growth was observed in any sample from the Cidex OPA immersion groups (1, 5, or 12 minutes), including the group treated with Tristel. These findings indicate that even a 1-minute immersion in Cidex OPA effectively eliminates bacterial contamination.
Conclusion
This study provides evidence supporting an efficient disinfection method that can enhance infection control and streamline clinical workflow. Further research with a larger sample size and varied disinfection techniques is needed to establish comprehensive disinfection guidelines for flexible laryngoscopes.
9.Comprehensive ultrasonographic evaluation of normal and fibrotic kidneys in a mouse model with an ultra-high-frequency transducer
Myoung Seok LEE ; Jeong Yeon CHO ; Min Hoan MOON ; Jeonghwan LEE ; Jung Pyo LEE ; Nayeon SHIN ; Wencheng JIN ; Ara CHO
Ultrasonography 2024;43(5):314-326
Purpose:
This study aimed to establish baseline morphological and functional data for normal mouse kidneys via a clinical 33 MHz ultra-high-frequency (UHF) transducer, compare the data with the findings from fibrotic mice, and assess correlations between ultrasonography (US) parameters and fibrosis-related markers.
Methods:
This retrospective study aggregated data from three separate experiments (obstructive nephropathy, diabetic nephropathy, and acute-to-chronic kidney injury models). Morphological parameters (kidney size, parenchymal thickness [PT]) and functional (shear-wave speed [SWS], stiffness, resistive index [RI], and microvascular imaging-derived vascular index [VI]) were assessed and compared between normal and fibrotic mouse kidneys. Semi-quantitative histopathologic scores were calculated and molecular markers (epithelial cadherin), Collagen 1A1 [Col1A1], transforming growth factor-β, and α-smooth muscle actin [α-SMA]) were evaluated using western blots. Correlations with US parameters were explored.
Results:
Clinical UHF US successfully imaged the kidneys of the experimental mice. A three-layer configuration was prevalent in the normal mouse kidney parenchyma (34/35) but was blurred in most fibrotic mouse kidneys (33/40). US parameters, including size (11.14 vs. 10.70 mm), PT (2.07 vs. 1.24 mm), RI (0.64 vs. 0.77), VI (22.55% vs. 11.47%, only for non-obstructive kidneys), SWS (1.67 vs. 2.06 m/s), and stiffness (8.23 vs. 12.92 kPa), showed significant differences between normal and fibrotic kidneys (P<0.001). These parameters also demonstrated strong discriminative ability in receiver operating characteristic curve analysis (area under the curve, 0.76 to 0.95; P<0.001). PT, VI, and RI were significantly correlated with histological fibrosis markers (ρ=-0.64 to -0.68 for PT and VI, ρ=0.71-0.76 for RI, P<0.001). VI exhibited strong negative correlations with Col1A1 (ρ=-0.76, P=0.006) and α-SMA (ρ=-0.75, P=0.009).
Conclusion
Clinical UHF US effectively distinguished normal and fibrotic mouse kidneys, indicating the potential of US parameters, notably VI, as noninvasive markers for tracking fibrosis initiation and progression in mouse kidney fibrosis models.
10.Comprehensive ultrasonographic evaluation of normal and fibrotic kidneys in a mouse model with an ultra-high-frequency transducer
Myoung Seok LEE ; Jeong Yeon CHO ; Min Hoan MOON ; Jeonghwan LEE ; Jung Pyo LEE ; Nayeon SHIN ; Wencheng JIN ; Ara CHO
Ultrasonography 2024;43(5):314-326
Purpose:
This study aimed to establish baseline morphological and functional data for normal mouse kidneys via a clinical 33 MHz ultra-high-frequency (UHF) transducer, compare the data with the findings from fibrotic mice, and assess correlations between ultrasonography (US) parameters and fibrosis-related markers.
Methods:
This retrospective study aggregated data from three separate experiments (obstructive nephropathy, diabetic nephropathy, and acute-to-chronic kidney injury models). Morphological parameters (kidney size, parenchymal thickness [PT]) and functional (shear-wave speed [SWS], stiffness, resistive index [RI], and microvascular imaging-derived vascular index [VI]) were assessed and compared between normal and fibrotic mouse kidneys. Semi-quantitative histopathologic scores were calculated and molecular markers (epithelial cadherin), Collagen 1A1 [Col1A1], transforming growth factor-β, and α-smooth muscle actin [α-SMA]) were evaluated using western blots. Correlations with US parameters were explored.
Results:
Clinical UHF US successfully imaged the kidneys of the experimental mice. A three-layer configuration was prevalent in the normal mouse kidney parenchyma (34/35) but was blurred in most fibrotic mouse kidneys (33/40). US parameters, including size (11.14 vs. 10.70 mm), PT (2.07 vs. 1.24 mm), RI (0.64 vs. 0.77), VI (22.55% vs. 11.47%, only for non-obstructive kidneys), SWS (1.67 vs. 2.06 m/s), and stiffness (8.23 vs. 12.92 kPa), showed significant differences between normal and fibrotic kidneys (P<0.001). These parameters also demonstrated strong discriminative ability in receiver operating characteristic curve analysis (area under the curve, 0.76 to 0.95; P<0.001). PT, VI, and RI were significantly correlated with histological fibrosis markers (ρ=-0.64 to -0.68 for PT and VI, ρ=0.71-0.76 for RI, P<0.001). VI exhibited strong negative correlations with Col1A1 (ρ=-0.76, P=0.006) and α-SMA (ρ=-0.75, P=0.009).
Conclusion
Clinical UHF US effectively distinguished normal and fibrotic mouse kidneys, indicating the potential of US parameters, notably VI, as noninvasive markers for tracking fibrosis initiation and progression in mouse kidney fibrosis models.

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