http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Ryu Dongryeol (검색결과 31 건)
- 무료
- 기관 내 무료
- 유료
-
Studies of Natural Small-Molecule Compounds Modulating the Aging of Muscle and Muscle Stem Cells
Dongryeol Ryu 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10
The first part of this talk will summarize recent publications investigated natural small-molecule compounds in muscle aging, briefly. Then, this talk will present our recent discovery in muscle stem cell senescence and its role in muscle regeneration. Our daily movement and physical activity entirely rely on skeletal muscle. Paradoxically, extreme physical activity exposes to a chance of muscle injury. The skeletal muscle, which often suffers from exercise-induced damage, has self-healing capacity. Muscle repair comprises several processes, including the activation and proliferation of quiescent resident muscle stem cells, also known as satellite cells. The diminished pool of muscle stem cells and their renewal ability are the major driving forces of muscle aging. Here, we show that acute muscle injury could trigger the senescence of muscle stem cells. However, we could find the sign of cellular senescence in the naturally aged muscle in mice. The second part will briefly show a machine learning-based prediction of biomarkers for muscle aging diseases, including sarcopenia and myositis.
-
-
TORC2 Regulates Hepatic Insulin Signaling via a Mammalian Phosphatidic Acid Phosphatase, LIPIN1
Ryu, Dongryeol,Oh, Kyoung-Jin,Jo, Hee-Yeon,Hedrick, Susan,Kim, Yo-Na,Hwang, Yu-Jin,Park, Tae-Sik,Han, Joong-Soo,Choi, Cheol Soo,Montminy, Marc,Koo, Seung-Hoi Elsevier 2009 Cell metabolism Vol.9 No.3
<P><B>Summary</B></P><P>TORC2 is a major transcriptional coactivator for hepatic glucose production. Insulin impedes gluconeogenesis by inhibiting TORC2 via SIK2-dependent phosphorylation at Ser171. Interruption of this process greatly perturbs hepatic glucose metabolism, thus promoting hyperglycemia in rodents. Here, we show that hyperactivation of TORC2 would exacerbate insulin resistance by enhancing expression of LIPIN1, a mammalian phosphatidic acid phosphatase for diacylglycerol (DAG) synthesis. Diet-induced or genetic obesity increases <I>LIPIN1</I> expression in mouse liver, and TORC2 is responsible for its transcriptional activation. While overexpression of LIPIN1 disturbs hepatic insulin signaling, knockdown of LIPIN1 ameliorates hyperglycemia and insulin resistance by reducing DAG and PKCϵ activity in <I>db/db</I> mice. Finally, TORC2-mediated insulin resistance is partially rescued by concomitant knockdown of LIPIN1, confirming the critical role of LIPIN1 in the perturbation of hepatic insulin signaling. These data propose that dysregulation of TORC2 would further exaggerate insulin resistance and promote type 2 diabetes in a LIPIN1-dependent manner.</P>
-
Endoplasmic Reticulum Stress Promotes LIPIN2-Dependent Hepatic Insulin Resistance
Ryu, Dongryeol,Seo, Woo-Young,Yoon, Young-Sil,Kim, Yo-Na,Kim, Su Sung,Kim, Hye-Jin,Park, Tae-Sik,Choi, Cheol Soo,Koo, Seung-Hoi American Diabetes Association 2011 Diabetes Vol.60 No.4
<P><B>OBJECTIVE</B></P><P>Diet-induced obesity (DIO) is linked to peripheral insulin resistance—a major predicament in type 2 diabetes. This study aims to identify the molecular mechanism by which DIO-triggered endoplasmic reticulum (ER) stress promotes hepatic insulin resistance in mouse models.</P><P><B>RESEARCH DESIGN AND METHODS</B></P><P>C57BL/6 mice and primary hepatocytes were used to evaluate the role of LIPIN2 in ER stress-induced hepatic insulin resistance. Tunicamycin, thapsigargin, and lipopolysaccharide were used to invoke acute ER stress conditions. To promote chronic ER stress, mice were fed with a high-fat diet for 8–12 weeks. To verify the role of LIPIN2 in hepatic insulin signaling, adenoviruses expressing wild-type or mutant LIPIN2, and shRNA for LIPIN2 were used in animal studies. Plasma glucose, insulin levels as well as hepatic free fatty acids, diacylglycerol (DAG), and triacylglycerol were assessed. Additionally, glucose tolerance, insulin tolerance, and pyruvate tolerance tests were performed to evaluate the metabolic phenotype of these mice.</P><P><B>RESULTS</B></P><P>LIPIN2 expression was enhanced in mouse livers by acute ER stress–inducers or by high-fat feeding. Transcriptional activation of LIPIN2 by ER stress is mediated by activating transcription factor 4, as demonstrated by LIPIN2 promoter assays, Western blot analyses, and chromatin immunoprecipitation assays. Knockdown of hepatic LIPIN2 in DIO mice reduced fasting hyperglycemia and improved hepatic insulin signaling. Conversely, overexpression of LIPIN2 impaired hepatic insulin signaling in a phosphatidic acid phosphatase activity–dependent manner.</P><P><B>CONCLUSIONS</B></P><P>These results demonstrate that ER stress–induced LIPIN2 would contribute to the perturbation of hepatic insulin signaling via a DAG-protein kinase C ε–dependent manner in DIO mice.</P>
-
Growth differentiation factor 15 is a myomitokine governing systemic energy homeostasis
Chung, Hyo Kyun,Ryu, Dongryeol,Kim, Koon Soon,Chang, Joon Young,Kim, Yong Kyung,Yi, Hyon-Seung,Kang, Seul Gi,Choi, Min Jeong,Lee, Seong Eun,Jung, Saet-Byel,Ryu, Min Jeong,Kim, Soung Jung,Kweon, Gi Rya The Rockefeller University Press 2017 The Journal of cell biology Vol.216 No.1
<P>Reduced mitochondrial electron transport chain activity promotes longevity and improves energy homeostasis via cell-autonomous and –non-autonomous factors in multiple model systems. This mitohormetic effect is thought to involve the mitochondrial unfolded protein response (UPR<SUP>mt</SUP>), an adaptive stress-response pathway activated by mitochondrial proteotoxic stress. Using mice with skeletal muscle–specific deficiency of <I>Crif1</I> (muscle-specific knockout [MKO]), an integral protein of the large mitoribosomal subunit (39S), we identified growth differentiation factor 15 (GDF15) as a UPR<SUP>mt</SUP>-associated cell–non-autonomous myomitokine that regulates systemic energy homeostasis. MKO mice were protected against obesity and sensitized to insulin, an effect associated with elevated GDF15 secretion after UPR<SUP>mt</SUP> activation. In <I>ob</I>/<I>ob</I> mice, administration of recombinant GDF15 decreased body weight and improved insulin sensitivity, which was attributed to elevated oxidative metabolism and lipid mobilization in the liver, muscle, and adipose tissue. Thus, GDF15 is a potent mitohormetic signal that safeguards against the onset of obesity and insulin resistance.</P>
-
-
Akuraju, Venkata Radha,Ryu, Dongryeol,George, Biju,Ryu, Youngryel,Dassanayake, Kithsiri Elsevier 2017 Agricultural and forest meteorology Vol.232 No.-
<P><B>Abstract</B></P> <P>It is assumed that the ratio of actual evapotranspiration (AET) to potential evapotranspiration (PET) is mostly controlled by the soil water content available for ET. This control is formulated using the soil moisture stress function (SSF), where the evaporative fraction (EF) or the fraction of the AET to PET (fPET) is assumed to be either a linear or a non-linear function of soil moisture. We examine the effectiveness of the soil moisture stress function to quantify soil moisture control on EF or fPET over a dryland wheat field in Victoria, Australia. Micrometeorological observations from two cropping seasons were used for the analysis. The efficacy of a root-density-weighted soil moisture estimate in predicting EF and fPET was investigated as against the commonly assumed fixed-depth root zone soil moisture. However, results indicate a strong relationship between EF and available soil water fraction (AWF) in the root zone only when solar radiation is higher than 5MJ/m<SUP>2</SUP>/day. As the rooting depth increases with vegetation growth, SSF exhibits the strongest correlation with AWF for increasing soil profile depth. In the early and harvesting crop growth stages, ET is constrained mostly by surface soil moisture (0–5cm). In the mid-growth stages, ET is strongly influenced by soil moisture in the root zone (0–60cm). The shape of SSF, however, changes significantly between the two years (2012 and 2013). It is inferred that different temporal rainfall patterns between the years caused wheat’s different response to water stress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Net radiation and crop phenology affect soil moisture stress function (SSF). </LI> <LI> Adaptive definition of root depth is important for accurate SSF. </LI> <LI> Root density profile needs to be used when defining root zone soil moisture. </LI> <LI> SSF can change inter-annually with temporal pattern of soil moisture. </LI> </UL> </P>
-
Mitochondrial Quality Control in the Heart: New Drug Targets for Cardiovascular Disease
Chang-Myung Oh,Dongryeol Ryu,Sungsoo Cho,Yangsoo Jang 대한심장학회 2020 Korean Circulation Journal Vol.50 No.5
Despite considerable efforts to prevent and treat cardiovascular disease (CVD), it has become the leading cause of death worldwide. Cardiac mitochondria are crucial cell organelles responsible for creating energy-rich ATP and mitochondrial dysfunction is the root cause for developing heart failure. Therefore, maintenance of mitochondrial quality control (MQC) is an essential process for cardiovascular homeostasis and cardiac health. In this review, we describe the major mechanisms of MQC system, such as mitochondrial unfolded protein response and mitophagy. Moreover, we describe the results of MQC failure in cardiac mitochondria. Furthermore, we discuss the prospects of 2 drug candidates, urolithin A and spermidine, for restoring mitochondrial homeostasis to treat CVD.
-
-
Does AMSR2 produce better soil moisture retrievals than AMSR-E over Australia?
Cho, Eunsang,Su, Chun-Hsu,Ryu, Dongryeol,Kim, Hyunglok,Choi, Minha Elsevier 2017 Remote sensing of environment Vol.188 No.-
<P><B>Abstract</B></P> <P>The Advanced Microwave Scanning Radiometer 2 (AMSR2), a follow-up microwave sensor to the AMSR for Earth Observing System (AMSR-E), was launched on the Global Change Observation Mission 1 – Water (GCOM-W1) satellite in May 2012. It is as yet unclear if instrumental improvements in AMSR2 over AMSR-E have led to better soil moisture (SM) estimates, especially since there is no overlapping period of data between the sensors. This study focuses on comparing the results of AMSR2 and AMSR-E SM over Australia, distinguishing four Köppen climate zones to determine if AMSR2 is better than AMSR-E. This is achieved by selecting two year-long comparative time periods from the operating periods of AMSR-E and AMSR2, based on their statistical similarities in modeled SM as a proxy, using Modern Era Retrospective-analysis for Research and Applications-Land (MERRA-L). The AMSR2 and AMSR-E C- and X-band SM derived from the Land Parameter Retrieval Model (LPRM) was evaluated. Both AMSR2 C- and X-band SM products were found to show similar temporal patterns and spatial agreement with AMSR-E C- and X-band SM, supported by unbiased root mean square difference (ubRMSD) and R-values with MERRA-L SM, respectively. Using lag-based instrumental variable analysis to estimate the random error component of SM retrievals, the noise-to-signal ratios in AMSR2 X-band SM were found to be slightly higher than their AMSR-E counterparts. The improvements in AMSR2, such as the superior radiometric sensitivity and spatial resolution, have therefore not led to statistically significant differences in performance for LPRM retrievals at 1/2°×1/2° grid resolution, when compared with AMSR-E. However, similarities in the metrics for AMSR2 and AMSR-E SM suggest that AMSR2 provides a valuable continuation to AMSR-E.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Revised the manuscript to reflect several specific comments carefully </LI> <LI> Clearly improved in textual and structural things </LI> <LI> Proofread thoroughly by a native English colleague </LI> </UL> </P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
