SMP30-mediated synthesis of vitamin C activates the liver PPARα/FGF21 axis to regulate thermogenesis in mice

Lee Bonggi,An Hye Jin,Kim Dae Hyun,Lee Min-Kyeong,Jeong Hyeon Hak,Chung Ki Wung,고영훈,Seo Arnold Y.,Kim Il Yong,Seong Je Kyung,Yu Byung Pal,LEE, JAE-WON,Im Eunok,Lee In-Kyu,Lee Myung-Shik,Yamada Ken-ich 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

The vitamin-C-synthesizing enzyme senescent marker protein 30 (SMP30) is a cold resistance gene in Drosophila, and vitamin C concentration increases in brown adipose tissue post-cold exposure. However, the roles of SMP30 in thermogenesis are unknown. Here, we tested the molecular mechanism of thermogenesis using wild-type (WT) and vitamin C-deficient SMP30-knockout (KO) mice. SMP30-KO mice gained more weight than WT mice without a change in food intake in response to short-term high-fat diet feeding. Indirect calorimetry and cold-challenge experiments indicated that energy expenditure is lower in SMP30-KO mice, which is associated with decreased thermogenesis in adipose tissues. Therefore, SMP30-KO mice do not lose weight during cold exposure, whereas WT mice lose weight markedly. Mechanistically, the levels of serum FGF21 were notably lower in SMP30-KO mice, and vitamin C supplementation in SMP30-KO mice recovered FGF21 expression and thermogenesis, with a marked reduction in body weight during cold exposure. Further experiments revealed that vitamin C activates PPARα to upregulate FGF21. Our findings demonstrate that SMP30-mediated synthesis of vitamin C activates the PPARα/FGF21 axis, contributing to the maintenance of thermogenesis in mice.

Immunomodulatory Role of Neuropeptide Y in Intestinal Inflammation

Yunna Lee(Yunna Lee),Eunok Im(Eunok Im) 대한약학회 2023 약학회지 Vol.67 No.1

Neuropeptide Y (NPY) is a 36-amino acid peptide found in the brain, autonomic nervous system, and different peripheral tissues, including the gastrointestinal (GI) tract. Dysfunction of the NPY or NPY system has been implicated in various tumor microenvironments and cardiovascular and GI disorders, such as inflammatory bowel disease (IBD). IBD, including Crohn’s disease (CD) and ulcerative colitis (UC), is a major health concern due to its increasing incidence globally. Emerging evidence has demonstrated that NPY also acts as a potent immunomodulator by linking the nervous and immune systems. NPY plays an important role in immunopathology during intestinal inflammation. This paper discusses the potential role of NPY as a valuable biomarker for IBD due to its consistent upregulation in both in vivo and clinical studies. Consequently, it confirms the pro-inflammatory effects of NPY, providing a rational basis for targeting NPY signaling as a therapeutic strategy.

Subspecific Status of the Korean Tiger Inferred by Ancient DNA Analysis

Mu-Yeong Lee,Jee Yun Hyun,Seo-Jin Lee,Junghwa An,Eunok Lee,Mi-Sook Min,Junpei Kimura,Shin-ichiro Kawada,Nozomi Kurihara,Shu-Jin Luo,Stephen J. O’Brien,Warren E. Johnson,Hang Lee 한국동물분류학회 2012 Animal Systematics, Evolution and Diversity Vol.28 No.1

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of Amur tigers in Far Eastern Russia and northeastern China that might prevent gene flow, especially for a large carnivore with long-distance dispersal abilities. However, there has yet to be a genetic study to confirm the subspecific status of the Korean tiger. Bone samples from four tigers originally caught in the Korean peninsula were collected from two museums in Japan and the United States. Eight mitochondrial gene fragments were sequenced and compared to previously published tiger subspecies’ mtDNA sequences to assess the phylogenetic relationship of the Korean tiger. Three individuals shared an identical haplotype with the Amur tigers. One specimen grouped with Malayan tigers, perhaps due to misidentification or mislabeling of the sample. Our results support the conclusion that the Korean tiger should be classified as P. t. altaica, which has important implications for the conservation and reintroduction of Korean tigers.

Species Identification Key of Korean Mammal Hair

LEE, Eunok,CHOI, Tae-Young,WOO, Donggul,MIN, Mi-Sook,SUGITA, Shoei,LEE, Hang The Japanese Society of Veterinary Science 2014 The Journal of veterinary medical science Vol.76 No.5

<P><B>ABSTRACT</B></P><P>The hair microstructures of Korean terrestrial mammals from 23 species (22 wild and one domestic) were analyzed using light and scanning electron microscopy (SEM) to construct a hair identification key. The hairs were examined using the medulla structures and cuticular scales of guard hairs from the dorsal regions of mature adult animals. All cuticular scale structures in the hair of Rodentia, Lagomorpha, Carnivora and Insectivora showed the petal pattern, and those of Artiodactyla and Chiroptera showed the wave pattern and coronal pattern, respectively. Rodentia, Lagomorpha and Carnivora showed multicellular, and Insectivora and Artiodactyla showed unicellular regular, mesh or columnar in the medulla structures, respectively. Chiroptera did not show the medulla structures in their hair. We found that it is possible to distinguish between species and order based on general appearance, medulla structures and cuticular scales. Thus, we constructed a hair identification key with morphological characteristics from each species. This study suggests that hair identification keys could be useful in fields, such as forensic science, food safety and foraging ecology.</P>

Neuroprotective effects of 2,4-dinitrophenol in an acute model of Parkinson’s disease

Lee, Yujeong,Heo, Gwangbeom,Lee, Kyung Moon,Kim, Ah Hyun,Chung, Ki Wung,Im, Eunok,Chung, Hae Young,Lee, Jaewon Elsevier/North Holland 2017 Brain research Vol.1663 No.-

<P><B>Abstract</B></P> <P>Neurons depend on mitochondria for homeostasis and survival, and thus, mitochondrial dysfunction has been implicated in neurodegenerative diseases, including Parkinson’s disease (PD). Increasing evidence indicates the mitochondrial uncoupler, 2,4-dinitrophenol (DNP), protects neurons against neurodegeneration and enhances neural plasticity. Here, the authors evaluated the protective effects of intraperitoneally (i.p.) administered low dose DNP in an acute mouse model of PD. Mice were administered DNP (1 or 5mg/kg) for 12 consecutive days, and then on day 13, MPTP (20mg/kg, i.p.) was administered four times (with 2h intervals between injections) to induce PD. It was found that MPTP-induced motor dysfunction was ameliorated in the DNP-treated mice versus vehicle-treated controls. Additionally, DNP effectively attenuated dopaminergic neuronal loss observed in MPTP treated mice. Moreover, in primary cultured neurons, DNP at 10μM, but not at 100μM, prevented MPP<SUP>+</SUP>-induced cell death and mitochondrial membrane potential (MMP) reduction. In addition, DNP was observed to cause the nuclear translocation of Nrf2 in primary neurons. Taken together, these findings of the present study suggest that DNP protects dopaminergic neurons against neurodegeneration and maintains MMP integrity in PD by activating adaptive stress responses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> DNP attenuates MPTP-induced motor dysfunction and dopaminergic neuronal death. </LI> <LI> DNP pretreatment protects primary neurons against MPP<SUP>+</SUP>-induced cell death. </LI> <LI> Neuroprotective effects of DNP involve stabilization of MMP and adaptive stress response via Nrf2 activation. </LI> </UL> </P>

Microstructures in Blue Feathers of the Common Kingfisher

Lee, Eunok,Bae, Haejin,Jeon, Deok-Jin,Ji, Seungmuk,Yeo, Jong-Souk,Kim, Jinhee National Institute of Ecology 2021 국립생태원회보(PNIE) Vol.2 No.1

We measured the sizes of microstructures and the reflectance of blue feathers in the Common Kingfisher (Alcedo atthis). The colors were mainly produced in the barbs, which were composed of keratin sponge layers with air spaces and melanin rods. The reflectance spectra of back and tail feathers of the Common Kingfisher showed a peak with a broad plateau in the visible wavelength, whereas those of the wing feathers showed peaks in ultraviolet and visible and short-wavelengths. Moreover, the reflectance of back and tail feathers was higher than that of wing feathers. The blue color of the feathers comes from the keratin sponge layer due to coherent scattering. The back and tail feathers are composed of the keratin sponge layer only, and the wing feathers are composed of the keratin sponge layer and the keratin honeycomb structure. Due to the difference in these structures, it supposed that the reflectance is different. Determining why the reflectance spectra of the back and tail feathers were flattened will require further study.

Small RNAs induce the activation of the pro‐inflammatory TLR7 signaling pathway in aged rat kidney

Lee, Eun Kyeong,Chung, Ki Wung,Kim, Ye Ra,Ha, Sugyeong,Kim, Sung Dae,Kim, Dae Hyun,Jung, Kyung Jin,Lee, Bonggi,Im, Eunok,Yu, Byung Pal,Chung, Hae Young John Wiley and Sons Inc. 2017 Aging cell Vol.16 No.5

<P><B>Summary</B></P><P>We have recently reported that TLR‐related genes, including TLR7, are upregulated during aging. However, the role of TLR7 and its endogenous ligand in inflammation related to aging is not well defined. Here, we established that small RNAs trigger age‐related renal inflammation <I>via</I> TLR7 signaling pathway. We first investigated the expression changes of nine different TLRs in kidney of 6‐month‐old young rats and 20‐month‐old aged rats. The results revealed that the expression of TLR7 was the highest among nine TLRs in kidney of old rats compared to the young aged rats. Next, to assess the role of cellular RNA as a TLR7 ligand, we treated a renal tubular epithelial cell line with total RNA isolated from the kidney of young and old rats. The results showed that RNA isolated from old rats showed higher expression of TLR7, IL1β, and TNFα compared to that from young rats. Furthermore, RNA isolated from old rats induced IKKα/β/JNK/NF‐κB activation. To identify RNA that activates TLR7, we isolated small and large RNAs from old rat kidney and found that small RNAs increased TLR7 expression in cells. Finally, to investigate the local inflammatory response by small RNA, C57B/L6 mice were intraperitoneally injected with small RNAs isolated from young and old rats; thereby, RNA isolated from old rats induced higher inflammatory responses. Our study demonstrates that renal small RNAs from aged rats induce pro‐inflammatory processes <I>via</I> the activation of the TLR7/IKKα/β/JNK/NF‐κB signaling pathway, and highlights its causative role as a possible therapeutic target in age‐related chronic renal inflammation.</P>

ROSPath : An Intergrated Database for Reactive Oxygen Species-mediated Signaling Pathway

Lee, Kong-Joo,Paek, Eunok,Kim, Hee-Jung,Yang, Kap-Seok,Lee, Sanghyuk,Lee, Seung-Rock,Choi, Kiyoung,Park, Jisook 이화여자대학교 세포신호전달연구센터 2004 고사리 세포신호전달 심포지움 Vol. No.6

Progress in understanding complex signaling pathways and networks has been hampered by the current lack of a formal and structured collation of the available information, in a format suitable for analysis via software tools. In order to facilitate the organization. and understanding of such complex network of information, it is essential to have a formal means to represent and analyze cellular pathways. We have defined a formal ontology for cell-signaling events that allows us to describe these cellular pathways at various levels of abstractions. Using this formal representation, ROSPath(Reactive Oxygen Species related signaling Pathway) database system has been implemented and made available on the web(http://rospath.ewha.ac.kr). ROSPath is a database system for reactive oxygen species(ROS)-mediated cell signaling pathways and signaling processes in molecular detail, that facilitates a comprehensive understanding of the regulatory mechanisms in signaling pathways. ROSPath includes growth factor-, stress- and cytokine-induced signaling. It is a web-based structured repository of information on the signaling pathways of interest and provides a means for managing data produced by high-throughput tools such as proteomics and genomics. It also provides effective and flexible tools for querying, displaying and analyzing pathways, thus providing an integrated web environment for visualizing and manipulating ROS-mediated cell-signaling events.

MULTIDIMENSIONAL OPEN SYSTEM FOR VALVELESS PUMPING

JUNG, EUNOK,KIM, DO WAN,LEE, JONGGUL,LEE, WANHO Korean Mathematical Society 2015 대한수학회보 Vol.52 No.6

In this study, we present a multidimensional open system for valveless pumping (VP). This system consists of an elastic tube connected to two open tanks filled with a fluid under gravity. The two-dimensional elastic tube model is constructed based on the immersed boundary method, and the tank model is governed by a system of ordinary differential equations based on the work-energy principle. The flows into and out of the elastic tube are modeled in terms of the source/sink patches inside the tube. The fluid dynamics of this system is generated by the periodic compress-and-release action applied to an asymmetric region of the elastic tube. We have developed an algorithm to couple these partial differential equations and ordinary differential equations using the pressure-flow relationship and the linearity of the discretized Navier-Stokes equations. We have observed the most important feature of VP, namely, the existence of a unidirectional net flow in the system. Our computations are focused on the factors that strongly influence the occurrence of unidirectional flows, for example, the frequency, compression duration, and location of pumping. Based on these investigations, some case studies are performed to observe the details of the ow features.

Effects of Flour Storage Conditions on the Lipid Oxidation of Fried Products during Storage in the Dark

Yoosung Lee,Jiyeun Lee,Eunok Choe 한국식품과학회 2006 Food Science and Biotechnology Vol.15 No.3