Transient receptor potential vanilloid type-1 channel regulates diet-induced obesity, insulin resistance, and leptin resistance

Lee, Eunjung,Jung, Dae Young,Kim, Jong Hun,Patel, Payal R.,Hu, Xiaodi,Lee, Yongjin,Azuma, Yoshihiro,Wang, Hsun-Fan,Tsitsilianos, Nicholas,Shafiq, Umber,Kwon, Jung Yeon,Lee, Hyong Joo,Lee, Ki Won,Kim, The Federation of American Societies for Experimen 2015 The FASEB Journal Vol.29 No.8

<P>Insulin resistance is a major characteristic of obesity and type 2 diabetes, but the underlying mechanism is unclear. Recent studies have shown a metabolic role of capsaicin that may be mediated <I>via</I> the transient receptor potential vanilloid type-1 (TRPV1) channel. In this study, TRPV1 knockout (KO) and wild-type (WT) mice (as controls) were fed a high-fat diet (HFD), and metabolic studies were performed to measure insulin and leptin action. The TRPV1 KO mice became more obese than the WT mice after HFD, partly attributed to altered energy balance and leptin resistance in the KO mice. The hyperinsulinemic-euglycemic clamp experiment showed that the TRPV1 KO mice were more insulin resistant after HFD because of the ∼40% reduction in glucose metabolism in the white and brown adipose tissue, compared with that in the WT mice. Leptin treatment failed to suppress food intake, and leptin-mediated hypothalamic signal transducer and activator of transcription (STAT)-3 activity was blunted in the TRPV1 KO mice. We also found that the TRPV1 KO mice were more obese and insulin resistant than the WT mice at 9 mo of age. Taken together, these results indicate that lacking TRPV1 exacerbates the obesity and insulin resistance associated with an HFD and aging, and our findings further suggest that TRPV1 has a major role in regulating glucose metabolism and hypothalamic leptin’s effects in obesity.—Lee, E., Jung, D. Y., Kim, J. H., Patel, P. R., Hu, X., Lee, Y., Azuma, Y., Wang, H.-F., Tsitsilianos, N., Shafiq, U., Kwon, J. Y., Lee, H. J., Lee, K. W., Kim, J. K. Transient receptor potential vanilloid type-1 channel regulates diet-induced obesity, insulin resistance, and leptin resistance.</P>

Deep learning-based scalable and robust channel estimator for wireless cellular networks

Anseok Lee(Anseok Lee),Yongjin Kwon(Yongjin Kwon),Hanjun Park(Hanjun Park),Heesoo Lee(Heesoo Lee) 한국전자통신연구원 2022 ETRI Journal Vol.44 No.6

In this paper, we present a two-stage scalable channel estimator (TSCE), a deep learning (DL)-based scalable, and robust channel estimator for wireless cellular networks, which is made up of two DL networks to efficiently support different resource allocation sizes and reference signal configurations. Both networks use the transformer, one of cutting-edge neural network architecture, as a backbone for accurate estimation. For computation-efficient global feature extractions, we propose using window and window averaging-based self-attentions. Our results show that TSCE learns wireless propagation channels correctly and outperforms both traditional estimators and baseline DL-based estimators. Additionally, scalability and robustness evaluations are performed, revealing that TSCE is more robust in various environments than the baseline DL-based estimators.

Detrimental Effect of Bovine Serum Albumin in a Maturation Medium on Embryonic Development after Somatic Cell Nuclear Transfer in Pigs

Hanna Lee,Yongjin Lee,Bola Park,Fazle Elahi,Joohyeong Lee,Jung Hoon Choi,Seung Tae Lee,Choon-Keun Park,Sang-Hwan Hyun,Eunsong Lee 한국수정란이식학회 2014 한국동물생명공학회지 Vol.29 No.4

This study was designed to evaluate the effect of bovine serum albumin (BSA) in a maturation medium on oocyte maturation and embryonic development in pigs. Immature pig oocytes were matured for 44 h in a medium supplemented with 0.4% (w/v) BSA, 0.1% (w/v) polyvinyl alcohol (PVA), or 10% (v/v) pig follicular fluid (PFF). After IVM, oocytes reached metaphase II stage were activated for parthenogenesis (PA) or used as cytoplasts for somatic cell nuclear transfer (SCNT). Nuclear maturation (89.5%, 90.7% and 91.3% for BSA, PVA and PFF, respectively) and intraoocyte glutathione contents (1.20, 1.16 and 1.00 pixels/oocyte for BSA, PVA and PFF, respectively) were not altered by the macromolecules added to maturation medium. IVM of oocytes in a medium containing BSA (21.4%) and PVA (20.7%) showed significantly lower blastocyst formation after PA than culture in medium with PFF (39.2%). After SCNT, oocytes matured in medium with BSA showed decreased embryonic development to the blastocyst stage (9.2%) compared to those matured in medium with PFF (28.9%), while 23.6% of SCNT oocytes matured in medium with PVA developed to the blastocyst stage. When the effect of BSA in a maturation medium during the first 22 h and the second 22 h of IVM in combination with PFF or PVA was examined, PVA-BSA showed a higher nuclear maturation (94.1%) than BSA-PFF (84.5%). However, there was no significant difference in the blastocyst formation among tested combinations (47.3, 52.2, 50.0, 44.4 and 49.0% for PFF-PFF, PFF-BSA, PVA-BSA, BSA-PVA and BSA-PFF, respectively). Our results demonstrate that BSA and PVA added to maturation medium can support oocyte maturation comparable to PFF-supplemented medium. However, maturation of oocytes in a BSA-containing medium decreases embryonic development after PA and SCNT when compared with the medium supplemented with PFF.

Effect of Glycine and Various Osmolarities of Culture Medium on In Vitro Development of Parthenogenesis and Somatic Cell Nuclear Transfer Embryos in Pigs

Lee, Joohyeong,Lee, Yongjin,Jung, Hae Hong,Lee, Seung Tae,Lee, Geun-Shik,Lee, Eunsong The Korean Society of Embryo Transfer 2018 한국동물생명공학회지 Vol.33 No.4

The osmolarity of a medium that is commonly used for in vitro culture (IVC) of oocytes and embryos is lower than that of oviductal fluid in pigs. In vivo oocytes and embryos can resist high osmolarities to some extent due to the presence of organic osmolytes such as glycine and alanine. These amino acids act as a protective shield to maintain the shape and viability in high osmotic environments. The aim of this study was to determine the effects of glycine or/and alanine in medium with two different osmolarities (280 and 320 mOsm) during IVC on embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. To this end, IVC was divided into two stages; the 0-2 and 3-7 days of IVC. In each stage, embryos were cultured in medium with 280, 320, or 360 mOsm and their combinations with or without glycine or/and alanine according to the experimental design. Treatment groups were termed as, for example, "T(osmolarity of a medium used in 0-2 days of IVC)-(osmolarity of a medium used in 3-7 days of IVC)" T280-280 was served as control. When PA embryos were cultured in medium with various osmolarities, T320-280 showed a significantly higher blastocyst formation (29.0%) than control (22.2%) and T360-360 groups (6.9%). Glycine treatment in T320-280 significantly increased blastocyst formation (50.4%) compared to T320-280 only (36.5%) while no synergistic was observed after treatment with glycine and alanine together in T320-280 (45.7%). In contrast to PA embryonic development, the stimulating effect by the culture in T320-280 was not observed in SCNT blastocyst development (27.6% and 23.7% in T280-280 and T320-280, respectively) whereas the number of inner cell mass cells was significantly increased in T320-280 (6.1 cells vs. 9.6 cells). Glycine treatment significantly improved blastocyst formation of SCNT embryos in both T280-280 (27.6% vs. 38.0%) and T320-280 (23.7% vs. 35.3%). Our results demonstrate that IVC in T320-280 and treatment with glycine improves blastocyst formation of PA and SCNT embryos in pigs.

In vitro maturation using αMEM with reduced NaCl enhances maturation and developmental competence of pig oocytes after somatic cell nuclear transfer

Yongjin Lee,Joohyeong Lee,Sang-Hwan Hyun,Geun-Shik Lee,Eunsong Lee 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.2

Background: Compared to medium containing 108 mM sodium chloride (NaCl), in vitro maturation (IVM) using a simple medium with reduced (61.6 mM) NaCl increases the cytoplasmic maturation and embryonic development of pig oocytes. Objectives: This study determines the effect of a complex medium containing reduced NaCl on the IVM and embryonic development of pig oocytes. Methods: Pig oocytes were matured in Minimum Essential Medium Eagle-alpha modification (αMEM) supplemented with 61.6 (61αMEM) or 108 (108αMEM) mM NaCl, and containing polyvinyl alcohol (PVA) (αMEMP) or pig follicular fluid (PFF) (αMEMF). Medium-199 (M199) served as the control for conventional IVM. Cumulus cell expansion, nuclear maturation, intra-oocyte glutathione (GSH) contents, size of perivitelline space (PVS), and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) were evaluated after IVM. Results: Regardless of PVA or PFF supplementation, oocytes matured in 61αMEM showed increased intra-oocyte GSH contents and width of PVS (p < 0.05), as well as increased blastocyst formation (p < 0.05) after PA and SCNT, as compared to oocytes matured in 108αMEMP and M199. Under conditions of PFF-enriched αMEM, SCNT oocytes matured in 61αMEMF showed higher blastocyst formation (p < 0.05), compared to maturation in 108αMEMF and M199, whereas PA cultured oocytes showed no significant difference. Conclusions: IVM in αMEM supplemented with reduced NaCl (61.6 mM) enhances the embryonic developmental competence subsequent to PA and SCNT, which attributes toward improved oocyte maturation.

Effect of Glucose and Pyruvate in a Chemically Defined Maturation Medium Containing Reduced NaCl on Maturation and Embryonic Development of Pig Oocytes#

Yongjin Lee,Hanna Lee,Bola Park,Fazle Elahi,Joohyeong Lee,Choon-Keun Park,Sang-Hwan Hyun,Eunsong Lee 한국동물생명공학회(구 한국동물번식학회) 2015 발생공학 국제심포지엄 및 학술대회 Vol.2015 No.10

Detrimental Effect of Bovine Serum Albumin in a Maturation Medium on Embryonic Development after Somatic Cell Nuclear Transfer in Pigs

Lee, Hanna,Lee, Yongjin,Park, Bola,Elahi, Fazle,Lee, Joohyeong,Choi, Jung Hoon,Lee, Seung Tae,Park, Choon-Keun,Hyun, Sang-Hwan,Lee, Eunsong The Korean Society of Embryo Transfer 2014 한국동물생명공학회지 Vol.29 No.4

This study was designed to evaluate the effect of bovine serum albumin (BSA) in a maturation medium on oocyte maturation and embryonic development in pigs. Immature pig oocytes were matured for 44 h in a medium supplemented with 0.4% (w/v) BSA, 0.1% (w/v) polyvinyl alcohol (PVA), or 10% (v/v) pig follicular fluid (PFF). After IVM, oocytes reached metaphase II stage were activated for parthenogenesis (PA) or used as cytoplasts for somatic cell nuclear transfer (SCNT). Nuclear maturation (89.5%, 90.7% and 91.3% for BSA, PVA and PFF, respectively) and intraoocyte glutathione contents (1.20, 1.16 and 1.00 pixels/oocyte for BSA, PVA and PFF, respectively) were not altered by the macromolecules added to maturation medium. IVM of oocytes in a medium containing BSA (21.4%) and PVA (20.7%) showed significantly lower blastocyst formation after PA than culture in medium with PFF (39.2%). After SCNT, oocytes matured in medium with BSA showed decreased embryonic development to the blastocyst stage (9.2%) compared to those matured in medium with PFF (28.9%), while 23.6% of SCNT oocytes matured in medium with PVA developed to the blastocyst stage. When the effect of BSA in a maturation medium during the first 22 h and the second 22 h of IVM in combination with PFF or PVA was examined, PVA-BSA showed a higher nuclear maturation (94.1%) than BSA-PFF (84.5%). However, there was no significant difference in the blastocyst formation among tested combinations (47.3, 52.2, 50.0, 44.4 and 49.0% for PFF-PFF, PFF-BSA, PVA-BSA, BSA-PVA and BSA-PFF, respectively). Our results demonstrate that BSA and PVA added to maturation medium can support oocyte maturation comparable to PFF-supplemented medium. However, maturation of oocytes in a BSA-containing medium decreases embryonic development after PA and SCNT when compared with the medium supplemented with PFF.

Targeting of hepatocellular carcinoma with glypican‐3‐targeting peptide ligand

Lee, You La,Ahn, Byeong‐,Cheol,Lee, Yongjin,Lee, Sang‐,Woo,Cho, Je‐,Yoel,Lee, Jaetae John Wiley Sons, Ltd 2011 Journal of Peptide Science Vol.17 No.11

<P>Hepatocellular carcinoma is a common malignancy. The carcinoma cells express glypican‐3 (GPC‐3) on the cell membrane. GPC‐3 is also expressed in melanoma cells. Therefore, GPC‐3 might be a potential target for tumor imaging or therapy. Here, proteomic mass spectrometry was used to identify peptides that target GPC‐3‐expressing tumors. A mammalian expression vector expressing a FLAG‐GPC‐3 fusion protein was cloned for immunoprecipitation. With the use of liposomes, the vector was transfected into HepG2 (HepG2/FLAG‐GPC‐3) and HEK 293 cells, and the transfected cell lines were selected with geneticin. HepG2/FLAG‐GPC‐3 cells were used for immunoprecipitation of FLAG‐GPC‐3 fusion protein. Seven peptide candidates (L1–L7) were selected for GPC‐3‐targeting ligands by mass spectrometric analysis. The L5 peptide with 14 amino acids (Arg‐Leu‐Asn‐Val‐Gly‐Gly‐Thr‐Tyr‐Phe‐Leu‐Thr‐Thr‐Arg‐Gln) showed selective binding to the GPC‐3‐expressing tumor cells, as did a shortened L5 peptide (L5‐2) with seven amino acids (Tyr‐Phe‐Leu‐Thr‐Thr‐Arg‐Gln). These peptide ligands have potential as targeting moieties to GPC‐3‐expressing tumors for diagnostic and/or therapeutic purposes. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.</P>

Large Thermoelectric Figure-of-Merits from SiGe Nanowires by Simultaneously Measuring Electrical and Thermal Transport Properties

Lee, Eun Kyung,Yin, Liang,Lee, Yongjin,Lee, Jong Woon,Lee, Sang Jin,Lee, Junho,Cha, Seung Nam,Whang, Dongmok,Hwang, Gyeong S.,Hippalgaonkar, Kedar,Majumdar, Arun,Yu, Choongho,Choi, Byoung Lyong,Kim, J American Chemical Society 2012 NANO LETTERS Vol.12 No.6

<P>The strongly correlated thermoelectric properties have been a major hurdle for high-performance thermoelectric energy conversion. One possible approach to avoid such correlation is to suppress phonon transport by scattering at the surface of confined nanowire structures. However, phonon characteristic lengths are broad in crystalline solids, which makes nanowires insufficient to fully suppress heat transport. Here, we employed Si–Ge alloy as well as nanowire structures to maximize the depletion of heat-carrying phonons. This results in a thermal conductivity as low as ∼1.2 W/m-K at 450 K, showing a large thermoelectric figure-of-merit (ZT) of ∼0.46 compared with those of SiGe bulks and even ZT over 2 at 800 K theoretically. All thermoelectric properties were “simultaneously” measured from the same nanowires to facilitate accurate ZT measurements. The surface-boundary scattering is prominent when the nanowire diameter is over ∼100 nm, whereas alloying plays a more important role in suppressing phonon transport for smaller ones.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2012/nalefd.2012.12.issue-6/nl300587u/production/images/medium/nl-2012-00587u_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl300587u'>ACS Electronic Supporting Info</A></P>

IT 개발자의 능력이 경력몰입에 미치는 영향에 관한 연구

이용진(Lee, Yongjin),이충권(Lee, Choong Kwon),이유진(Lee, Yu-jin) 계명대학교 산학연구소 2014 經營經濟 Vol.47 No.2

연구목적 - 본 연구는 IT개발자의 여러 가지 능력들 중에서 어느 것이 이직능력을 구성하는 요소인지를 살펴보았고, 이러한 이직능력이 경력몰입과 연결되어 IT개발자의 이력과 능력이 결국엔 경력몰입과 관계를 가지고 있는지에 대하여 분석하였다. 연구방법 - IT개발자를 대상으로 직접 면접을 통하여 총 200부가 배부되었고, 153부의 설문지를 회수하였으며, 이들 중 IT개발자가 아닌 응답자와 불성실한 응답, 결측값을 제외하고, 총 126부의 설문지를 최종분석에 사용하였다. 주요 결과 - 변수로 선택된 기본능력, 기술적 능력, 비즈니스 관련 능력, 행동적 능력 모두 이직능력에 정의 영향을 주는 것으로 파악되었다. 또한 이직능력은 경력몰입과 정의 영향을 주는 것으로 파악되었다. 특히 행동적 능력이 이직능력과 가장 높은 상관관계를 가지는 것으로 분석되어 IT개발자의 역량에서 중요한 요인이 기술보다는 행동이나 태도에 있음이 검증되었다. 시사점 - 과거의 정보시스템 관련 업무는 개발자 개개인의 능력이 최대한 발휘되는 직종이라고 생각되었지만, 본 연구는 개인적인 업무수행 능력뿐만 아니라 다른 사람과의 관계를 유지 발전시킬 수 있는 능력도 중요하다는 것을 발견하였다. Purpose - This research examined the career background and abilities of IT developers to see which factors significantly influence turnover ability. Furthermore, an analysis was conducted on the relationship between turnover ability and career commitment, and whether this relationship ultimately mediates the relationship between career background and abilities of IT developers and career commitment. Design/Methodology - A total of 200 survey questionnaires were distributed to IT developers and 153 of them responded. After eliminating reponses with inappropriate answers, we used 126 responses for the further analysis. Findings - The selected variables of basic ability, technical ability, business ability, behavioral ability all had a positive effect on turnover ability. Also, turnover ability showed a positive effect on career commitment. However, behavioral ability showed to have the highest correlation with turnover ability which verified that, out of an IT developers capabilities, behavior and attitude are more important factors than skill. Implications - IT development tasks are no longer strictly based on technical skills as it was perceived in the past, and are not like technical jobs where skill acquirement is the only necessity for recognition. Thus, because IT development works around an environment collaborating with other people, presenting to people, and developing for people, developers who can get along with others, communicate fluently, and have passion are evaluated as being more capable.