1.Nicotinamide mononucleotide attenuates hepatic endoplasmic reticulum stress and modulates circadian rhythms in young mice with diet-induced obesity
So Young KWON ; Khuhee NA ; Yerim HAN ; Seungmin SONG ; Yoon Jung PARK
Nutrition Research and Practice 2026;20(2):220-238
BACKGROUND/OBJECTIVES:
Supplementation of nicotinamide adenine dinucleotide (NAD) precursors has been investigated for its potential to counteract age-related physiological decline. While decreased NAD + level is associated with conditions such as obesity and dyslipidemia, few studies have explored its metabolic impact in relatively young animals.Here, we hypothesized that nicotinamide mononucleotide (NMN) could alleviate highfat diet-induced metabolic stress in young mice and sought to elucidate the underlying mechanisms.MATERIALS/METHODS: We first conducted a secondary analysis of hepatic transcriptome datasets from multiple NMN intervention studies to identify target pathways. Next, 11-weekold lean and obese C57BL/6N mice administrated NMN (500 mg/kg/day) for 1 mon were analyzed for metabolic parameters and gene expression for the target pathways. In vitro study using AML12 cell line was then conducted to confirm the effects of NMN. Additionally, transcriptomic data from liver-specific nicotinamide phosphoribosyltransferase (NAMPT)-deficient mice were analyzed to examine the relationship between NAD + metabolism, endoplasmic reticulum (ER) stress, and circadian rhythm.
RESULTS:
The secondary analysis of hepatic transcriptome datasets revealed potential target pathways related to circadian regulation and hepatic ER stress. In mouse study, short-term NMN administration significantly decreased body weight and fat mass. NMN also alleviated hepatic ER stress response in vivo and in vitro. Additional analysis revealed that the mice with diet-induced metabolic stress or NAMPT deficiency led to phase shifts of the hepatic circadian core clock oscillation by advancing the peak time, while time-restricted feeding shifted the opposite, indicating the metabolic regulation of the circadian phase.
CONCLUSION
Short-term NMN administration effectively attenuated obese condition in young mice and mitigated hepatic ER stress. The altered ER stress was regulated by NAMPT, potentially through the phase shift of the hepatic circadian rhythm.
2.Intertwined relationship of dietary patterns and circadian clock
Jinyoung SHON ; Yerim HAN ; Yoon Jung PARK
Journal of Nutrition and Health 2025;58(6):531-540
Circadian rhythms orchestrate daily fluctuations in feeding behavior, hormonal activity, and metabolic function through coordinated interactions between the central clock and peripheral oscillators. Dietary patterns, defined by both macronutrient composition and the timing of food intake, function as potent cues that reshape these rhythms. This narrative review summarizes experimental evidence describing how diet influences circadian organization and how circadian disruption alters metabolic outcomes primarily in murine models. Genetic disruption of core clock components such as CLOCK, BMAL1, CRY, or PER abolishes feeding rhythmicity and desynchronizes metabolic pathways, resulting in obesity, impaired glucose regulation, and hepatic lipid accumulation. Dietary composition also influences circadian organization, as high-fat, ketogenic, or modified-protein diets shift the phase or amplitude of peripheral clock gene rhythms and alter metabolic outputs across tissues. Feeding-time misalignment produces substantial phase shifts in hepatic and adipose oscillations and aggravates diet-induced metabolic dysfunction. In contrast, restricting food intake to consistent daily windows restores rhythmic metabolic states in the liver, adipose tissue, and intestine and improves systemic homeostasis even without reducing caloric intake. Together, these findings show that both macronutrient composition and feeding-time alignment influence the phase and synchrony of peripheral circadian rhythms and the metabolic processes governed by these rhythms. Understanding these relationships provides mechanistic insight into diet–circadian interactions and supports the development of circadian-aligned dietary strategies aimed at promoting metabolic stability.
3.Effects of Natural Versus Synthetic Consonant and Vowel Stimuli on Cortical Auditory-Evoked Potential
Hyunwook SONG ; Seungik JEON ; Yerim SHIN ; Woojae HAN ; Saea KIM ; Chanbeom KWAK ; Eunsung LEE ; Jinsook KIM
Journal of Audiology & Otology 2022;26(2):68-75
Background and Objectives:
Natural and synthetic speech signals effectively stimulate cortical auditory evoked potential (CAEP). This study aimed to select the speech materials for CAEP and identify CAEP waveforms according to gender of speaker (GS) and gender of listener (GL).
Subjects and Methods:
Two experiments including a comparison of natural and synthetic stimuli and CAEP measurement were performed of 21 young announcers and 40 young adults. Plosive /g/ and /b/ and aspirated plosive /k/ and /p/ were combined to /a/. Six bisyllables–/ga/-/ka/, /ga/-/ba/, /ga/-/pa/, /ka/-/ba/, /ka/-/pa/, and /ba/-/pa/–were formulated as tentative forwarding and backwarding orders. In the natural and synthetic stimulation mode (SM) according to GS, /ka/ and /pa/ were selected through the first experiment used for CAEP measurement.
Results:
The correction rate differences were largest (74%) at /ka/-/ pa/ and /pa/-/ka/; thus, they were selected as stimulation materals for CAEP measurement. The SM showed shorter latency with P2 and N1-P2 with natural stimulation and N2 with synthetic stimulation. The P2 amplitude was larger with natural stimulation. The SD showed significantly larger amplitude for P2 and N1-P2 with /pa/. The GS showed shorter latency for P2, N2, and N1-P2 and larger amplitude for N2 with female speakers. The GL showed shorter latency for N2 and N1-P2 and larger amplitude for N2 with female listeners.
Conclusions
Although several variables showed significance for N2, P2, and N1-P2, P1 and N1 did not show any significance for any variables. N2 and P2 of CAEP seemed affected by endogenous factors.
4.Far-infrared rays enhance mitochondrial biogenesis and GLUT3 expression under low glucose conditions in rat skeletal muscle cells
Yelim SEO ; Young-Won KIM ; Donghee LEE ; Donghyeon KIM ; Kyoungseo KIM ; Taewoo KIM ; Changyeob BAEK ; Yerim LEE ; Junhyeok LEE ; Hosung LEE ; Geonwoo JANG ; Wonyeong JEONG ; Junho CHOI ; Doegeun HWANG ; Jung Soo SUH ; Sun-Woo KIM ; Hyoung Kyu KIM ; Jin HAN ; Hyoweon BANG ; Jung-Ha KIM ; Tong ZHOU ; Jae-Hong KO
The Korean Journal of Physiology and Pharmacology 2021;25(2):167-175
Far-infrared rays (FIR) are known to have various effects on atoms and molecular structures within cells owing to their radiation and vibration frequencies. The present study examined the effects of FIR on gene expression related to glucose transport through microarray analysis in rat skeletal muscle cells, as well as on mitochondrial biogenesis, at high and low glucose conditions. FIR were emitted from a bio-active material coated fabric (BMCF). L6 cells were treated with 30% BMCF for 24 h in medium containing 25 or 5.5 mM glucose, and changes in the expression of glucose transporter genes were determined. The expression of GLUT3 (Slc2a3) increased 2.0-fold (p < 0.05) under 5.5 mM glucose and 30% BMCF. In addition, mitochondrial oxygen consumption and membrane potential (ΔΨm) increased 1.5- and 3.4-fold (p < 0.05 and p < 0.001), respectively, but no significant change in expression of Pgc-1a, a regulator of mitochondrial biogenesis, was observed in 24 h. To analyze the relationship between GLUT3 expression and mitochondrial biogenesis under FIR, GLUT3 was down-modulated by siRNA for 72 h. As a result, the ΔΨm of the GLUT3 siRNA-treated cells increased 3.0-fold (p < 0.001), whereas that of the control group increased 4.6-fold (p < 0.001). Moreover, Pgc-1a expression increased upon 30% BMCF treatment for 72 h; an effect that was more pronounced in the presence of GLUT3. These results suggest that FIR may hold therapeutic potential for improving glucose metabolism and mitochondrial function in metabolic diseases associated with insufficient glucose supply, such as type 2 diabetes.
5.Far-infrared rays enhance mitochondrial biogenesis and GLUT3 expression under low glucose conditions in rat skeletal muscle cells
Yelim SEO ; Young-Won KIM ; Donghee LEE ; Donghyeon KIM ; Kyoungseo KIM ; Taewoo KIM ; Changyeob BAEK ; Yerim LEE ; Junhyeok LEE ; Hosung LEE ; Geonwoo JANG ; Wonyeong JEONG ; Junho CHOI ; Doegeun HWANG ; Jung Soo SUH ; Sun-Woo KIM ; Hyoung Kyu KIM ; Jin HAN ; Hyoweon BANG ; Jung-Ha KIM ; Tong ZHOU ; Jae-Hong KO
The Korean Journal of Physiology and Pharmacology 2021;25(2):167-175
Far-infrared rays (FIR) are known to have various effects on atoms and molecular structures within cells owing to their radiation and vibration frequencies. The present study examined the effects of FIR on gene expression related to glucose transport through microarray analysis in rat skeletal muscle cells, as well as on mitochondrial biogenesis, at high and low glucose conditions. FIR were emitted from a bio-active material coated fabric (BMCF). L6 cells were treated with 30% BMCF for 24 h in medium containing 25 or 5.5 mM glucose, and changes in the expression of glucose transporter genes were determined. The expression of GLUT3 (Slc2a3) increased 2.0-fold (p < 0.05) under 5.5 mM glucose and 30% BMCF. In addition, mitochondrial oxygen consumption and membrane potential (ΔΨm) increased 1.5- and 3.4-fold (p < 0.05 and p < 0.001), respectively, but no significant change in expression of Pgc-1a, a regulator of mitochondrial biogenesis, was observed in 24 h. To analyze the relationship between GLUT3 expression and mitochondrial biogenesis under FIR, GLUT3 was down-modulated by siRNA for 72 h. As a result, the ΔΨm of the GLUT3 siRNA-treated cells increased 3.0-fold (p < 0.001), whereas that of the control group increased 4.6-fold (p < 0.001). Moreover, Pgc-1a expression increased upon 30% BMCF treatment for 72 h; an effect that was more pronounced in the presence of GLUT3. These results suggest that FIR may hold therapeutic potential for improving glucose metabolism and mitochondrial function in metabolic diseases associated with insufficient glucose supply, such as type 2 diabetes.
6.Occupational Performance of Hearing-Impaired and Normal-Hearing Workers in Korea
Jinsook KIM ; Yerim SHIN ; Seungwan LEE ; Eunsung LEE ; Woojae HAN ; Jihyeon LEE
Journal of Audiology & Otology 2021;25(4):189-198
Background and Objectives:
This study aimed to investigate the occupational performance of Korean workers with and without hearing loss and analyze the hearing-related difficulties in the working environment.
Subjects and Methods:
The Amsterdam checklist for hearing and work was used for the analyses and the occupational environments of the Korean workers were investigated. Out of 129 total participants, 86 workers experienced severe to profound hearing loss and 43 had the normal hearing ability. The hearing-impaired workers were recruited from two leading vocational centers and normal-hearing workers were their colleagues.
Results:
The hearing-impaired workers were found to take fewer sick leaves and exhibited higher rates of permanent job statuses compared to the normal-hearing workers. Workers with hearing loss rarely detected background sound; however, they could perceive reverberation more frequently. They felt more satisfied with their careers than the normal hearing workers as they received social support and needed to put their effort into hearing for most hearing activities. Furthermore, the effort in hearing increased with the increase in job demand, job control, social support, and career satisfaction. The working hours per week increased with the increase in age, education level, job demand, job control, and social support. Different trends were observed in 9 out of 12 variables while comparing the data from the present study with that obtained from the hearing-impaired workers of the Netherlands, indicating a large difference between countries.
Conclusions
Although the hearing-impaired Korean workers operate diligently with good job positions, it is necessary to enhance their acoustic environment and provide them social support. Considering the cultural background of the hearing-impaired workers, the development of suitable vocational rehabilitation programs and specific questionnaires is strongly recommended worldwide.
7.Organizing an in-class hackathon to correct PDF-to-text conversion errors of Genomics & Informatics 1.0
Sunho KIM ; Royoung KIM ; Ryeo-Gyeong KIM ; Enjin KO ; Han-Su KIM ; Jihye SHIN ; Daeun CHO ; Yurhee JIN ; Soyeon BAE ; Ye Won JO ; San Ah JEONG ; Yena KIM ; Seoyeon AHN ; Bomi JANG ; Jiheyon SEONG ; Yujin LEE ; Si Eun SEO ; Yujin KIM ; Ha-Jeong KIM ; Hyeji KIM ; Hye-Lynn SUNG ; Hyoyoung LHO ; Jaywon KOO ; Jion CHU ; Juwon LIM ; Youngju KIM ; Kyungyeon LEE ; Yuri LIM ; Meongeun KIM ; Seonjeong HWANG ; Shinhye HAN ; Sohyeun BAE ; Sua KIM ; Suhyeon YOO ; Yeonjeong SEO ; Yerim SHIN ; Yonsoo KIM ; You-Jung KO ; Jihee BAEK ; Hyejin HYUN ; Hyemin CHOI ; Ji-Hye OH ; Da-Young KIM ; Hee-Jo NAM ; Hyun-Seok PARK
Genomics & Informatics 2020;18(3):e33-
This paper describes a community effort to improve earlier versions of the full-text corpus of Genomics & Informatics by semi-automatically detecting and correcting PDF-to-text conversion errors and optical character recognition errors during the first hackathon of Genomics & Informatics Annotation Hackathon (GIAH) event. Extracting text from multi-column biomedical documents such as Genomics & Informatics is known to be notoriously difficult. The hackathon was piloted as part of a coding competition of the ELTEC College of Engineering at Ewha Womans University in order to enable researchers and students to create or annotate their own versions of the Genomics & Informatics corpus, to gain and create knowledge about corpus linguistics, and simultaneously to acquire tangible and transferable skills. The proposed projects during the hackathon harness an internal database containing different versions of the corpus and annotations.
8.Organizing an in-class hackathon to correct PDF-to-text conversion errors of Genomics & Informatics 1.0
Sunho KIM ; Royoung KIM ; Ryeo-Gyeong KIM ; Enjin KO ; Han-Su KIM ; Jihye SHIN ; Daeun CHO ; Yurhee JIN ; Soyeon BAE ; Ye Won JO ; San Ah JEONG ; Yena KIM ; Seoyeon AHN ; Bomi JANG ; Jiheyon SEONG ; Yujin LEE ; Si Eun SEO ; Yujin KIM ; Ha-Jeong KIM ; Hyeji KIM ; Hye-Lynn SUNG ; Hyoyoung LHO ; Jaywon KOO ; Jion CHU ; Juwon LIM ; Youngju KIM ; Kyungyeon LEE ; Yuri LIM ; Meongeun KIM ; Seonjeong HWANG ; Shinhye HAN ; Sohyeun BAE ; Sua KIM ; Suhyeon YOO ; Yeonjeong SEO ; Yerim SHIN ; Yonsoo KIM ; You-Jung KO ; Jihee BAEK ; Hyejin HYUN ; Hyemin CHOI ; Ji-Hye OH ; Da-Young KIM ; Hee-Jo NAM ; Hyun-Seok PARK
Genomics & Informatics 2020;18(3):e33-
This paper describes a community effort to improve earlier versions of the full-text corpus of Genomics & Informatics by semi-automatically detecting and correcting PDF-to-text conversion errors and optical character recognition errors during the first hackathon of Genomics & Informatics Annotation Hackathon (GIAH) event. Extracting text from multi-column biomedical documents such as Genomics & Informatics is known to be notoriously difficult. The hackathon was piloted as part of a coding competition of the ELTEC College of Engineering at Ewha Womans University in order to enable researchers and students to create or annotate their own versions of the Genomics & Informatics corpus, to gain and create knowledge about corpus linguistics, and simultaneously to acquire tangible and transferable skills. The proposed projects during the hackathon harness an internal database containing different versions of the corpus and annotations.
9.Accidental Swallowing of Nasal Packing Gauze during Silicone Tube Intubation under Local Anesthesia
Jeong Han KONG ; Yerim AN ; Youn Joo CHOI
Journal of the Korean Ophthalmological Society 2020;61(5):550-553
Purpose:
To report a case of accidental swallowing of nasal packing gauze during silicone tube intubation under local anesthesia.Case summary: A 58-year-old male patient underwent silicone tube intubation for partial nasolacrimal duct obstruction on the right side. In preparing for surgery, six cottonoids soaked were packed in righ nasal cavity, to facilitate anesthesia and prevent bleeding. Strings detectable by X-ray were attached at the cottonoids and cut 5 cm from the nostrils. After surgical hand scrubbing, the strings were not present. One cottonoid was found in the nasal cavity, but five cottonoids could not be detected by endonasal endoscopic exploration. The patient said he swallowed “something like sputum”. He did not notice any discomfort and the surgery was performed as scheduled. Abdominal X-ray performed immediately after surgery showed the presence of the five strings in the stomach. The strings were not seen on X-ray conducted 4 days later. The patient defecated normal stools three times and did not notice any discomfort over the course of 4 days.
Conclusions
Surgeons need to be aware of the possibility of accidental swallowing of nasal packing gauze during nasolacrimal duct surgery. Use of gauze detectable by X-ray is helpful to determine its location.
10.An Unusual Case of Benign Episodic Bilateral Mydriasis
Ye Rim AHN ; Han Ul KIM ; Yerim KIM ; Youn Joo CHOI
Journal of the Korean Ophthalmological Society 2019;60(9):901-904
PURPOSE: Although benign episodic mydriasis has been rarely reported worldwide, most of the reports so far have occurred in unilaterally. To report an unusual case of benign episodic bilateral mydriasis. CASE SUMMARY: Nineteen-year-old woman who presented with intermittent dilation of both pupils two months ago. She had difficulty on reading and doing tasks because of her visual blur. This symptom usually lasted for 1–2 hours, occurred once every 2–3 days, most frequently during stressful situations. Headaches and dizziness accompanied the eye symptoms, and her pupils were both 5 mm in a lighted room and both 7 mm in a dark room. All tests, including brain magnetic resonance imaging, showed no abnormal findings. We diagnosed her as benign episodic bilateral mydriasis. The frequency of her symptoms decreased during the university vacation period. CONCLUSIONS: In the absence of ophthalmologic or neurologic abnormalities other than headaches in patients with transient mydriasis, benign episodic mydriasis should be considered as a differential diagnosis. Although benign episodic bilateral mydriasis has a unilateral predominance, for the first time the authors report that benign episodic mydriasis may occur in both eyes during same episode.
Brain
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Diagnosis, Differential
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Dizziness
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Female
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Headache
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Humans
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Magnetic Resonance Imaging
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Mydriasis
;
Pupil

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