• Title/Summary/Keyword: energy homeostasis

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Explaining One Less Nuclear Energy Policy from Governance Perspective: Energy Transition and Effectiveness of Urban Energy Policy (대안적 에너지 정책에 대한 탐색: 서울시 원전하나 줄이기 정책과 거버넌스의 역할)

  • Lee, Joo Hun
    • Korean Journal of Legislative Studies
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    • v.23 no.1
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    • pp.151-185
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    • 2017
  • Seoul's One Less Nuclear Power Plant is the major urban energy policy launched in April 2012. Its effort to respond to climate change and energy crisis in the aftermath of the Fukushima nuclear accident turned out very successful, considering huge decrease of energy consumption. However, the question of how the cut of energy consumption was possible remains unanswered. This paper introduces the concept of urban governance capacity as the cause of the success. It is the managing and governing capability to maintain the logical consistency policy system, comprising of policy perception, goals, policy tools and evaluation. Without this logical correspondence between the policy factors, any system including energy regime easily falls apart during the systemic transitional period. Governance capacity provides the integrating framework, so that the system as a whole maintains the internal homeostasis.

Modulation of the Somatotropic Axis in Periparturient Dairy Cows

  • Kim, Jin Wook
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.1
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    • pp.147-154
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    • 2014
  • This review focuses on modulation of growth hormone (GH) and its downstream actions on periparturient dairy cows undergoing physiological and metabolic adaptations. During the periparturient period, cows experience a negative energy balance implicating that the feed intake does not meet the total energy demand for the onset of lactation. To regulate this metabolic condition, key hormones of somatotropic axis such as GH, IGF-I and insulin must coordinate adaptations required for the preservation of metabolic homeostasis. The hepatic GHR1A transcript and GHR protein are reduced at parturition, but recovers on postpartum. However, plasma IGF-I concentration remains low even though hepatic abundance of the GHR and IGF-I mRNA return to pre-calving value. This might be caused by alternation in IGFBPs and ALS genes, which consequently affect the plasma IGF-I stability. Plasma insulin level declines in a parallel manner with the decrease in plasma IGF-I after parturition. Increased GH stimulates the lipolytic effects and hepatic glucose synthesis to meet the energy requirement for mammary lactose synthesis, suggesting that GH antagonizes insulin-dependent glucose uptake and attenuates insulin action to decrease gluconeogenesis.

Cellular Contributors to Hypothalamic Inflammation in Obesity

  • Lee, Chan Hee;Suk, Kyoungho;Yu, Rina;Kim, Min-Seon
    • Molecules and Cells
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    • v.43 no.5
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    • pp.431-437
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    • 2020
  • The hypothalamus is a crucial organ for the maintenance of appropriate body fat storage. Neurons in the hypothalamic arcuate nucleus (ARH) detect energy shortage or surplus via the circulating concentrations of metabolic hormones and nutrients, and then coordinate energy intake and expenditure to maintain energy homeostasis. Malfunction or loss of hypothalamic ARH neurons results in obesity. Accumulated evidence suggests that hypothalamic inflammation is a key pathological mechanism that links chronic overconsumption of a high-fat diet (HFD) with the development of obesity and related metabolic complications. Interestingly, overnutrition-induced hypothalamic inflammation occurs specifically in the ARH, where microglia initiate an inflammatory response by releasing proinflammatory cytokines and chemokines in response to excessive fatty acid flux. Upon more prolonged HFD consumption, astrocytes and perivascular macrophages become involved and sustain hypothalamic inflammation. ARH neurons are victims of hypothalamic inflammation, but they may actively participate in hypothalamic inflammation by sending quiescence or stress signals to surrounding glia. In this mini-review, we describe the current state of knowledge regarding the contributions of neurons and glia, and their interactions, to HFD-induced hypothalamic inflammation.

Adipocyte-Related Genes and Transcription Factors were affected by Ganoderma lucidum during 3T3-L1 Differentiation (지방세포 분화중인 3T3-L1 세포에서 영지추출물에 의한 지방관련 유전자와 전사인자의 발현 조절)

  • Lee, Chae-Woo;Yoon, Hyun-Min;Kang, Kyung-Hwa
    • Journal of Pharmacopuncture
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    • v.12 no.2
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    • pp.13-20
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    • 2009
  • In this study, the effects of Ganoderma lucidum (GL) on fat metabolism were performed in 3T3-L1 adipocytes. The effects of GL on 3T3-L1 preadipocytes differentiation were also examined. Our results showed that GL decreased the TG content by ORO staining. To elucidate the mechanism of the effects of GL on lowering TG content in 3T3-L1 adipocytes, we examined whether GL modulate the expressions of transcription factors and adipokines related to control of energy expenditure process because adipokines regulate adipocyte mass and increased expenditure may consume much TG in adipocytes. As a result, the expression of C/$EBP{\beta}$, C/$EBP{\delta}$, C/$EBP{\alpha}$, and $PPAR{\gamma}$, genes, which induce the adipose differentiation and adipose-specific FAS, aP2, and adipsin genes, which compose fat formation were decreased. In addition, GL increased the expression of leptin, UCP2, adiponectin in 3T3-L1 adipocytes, resulting in energy homeostasis. In conclusion, GL could regulate transcript factor related to induction of adipose differentiation and control TG content by up-regulation of adipokines related to fat burn.

Anti-obesity Effects and Mechanism of Original and Modified Gambejaeseup-tang in Female Rats with Diet-induced Obesity (고지방식이로 유발된 비만 백서에서 가미감비제습탕이 비만 유발에 미치는 영향 및 기전 연구)

  • Park, Sun-Min;Kim, Da-Sol;Kang, Sun-A;Lee, Jung-Bok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.4
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    • pp.646-652
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    • 2010
  • Gambejaeseup-tang (GBJST) have recently been used as an anti-obesity herbal medicine but their effect and mechanism of action have not been studied. We modified ingredients of GBJST based on the previous experiments about exploring herbs to suppress triglyceride accumulation in 3T3-L1 adipocytes. We investigated the effects of modified GBJST on energy, glucose and lipid homeostasis using female rats with diet-induced obesity and their action mechanism was also determined. Rats fed a high-fat diet (HFD) were divided into 3 groups: rats in each group received 0.2 or 2 g water extracts of modified GBJST (L-GBJST or H-GBJST) or 2 g cellulose per kg body weight (a negative control) on a daily basis. A further group was fed a low-fat diet (LFD) as a positive control. We found that modified GBJST dose-dependently decreased body weight and mesenteric and retroperitoneal fat more than the control. This decrease was due to the reduction in energy intake and the increase of energy expenditure. HFD increased fat oxidation more than LFD and modified GBJST further increased fat oxidation as a major energy source more than the control in a dose-dependent manner. In addition, H-GBJST improved glucose tolerance without changing serum insulin levels during an oral glucose tolerance test. H-GBJST also suppressed the increase of serum total and LDL cholesterol and triglyceride levels by HFD. In conclusion, modified GBJST have a good anti-obesity effect by decreasing energy intake and increasing energy expenditure mainly as fat in female rats with diet-induced obesity. It also improves glucose tolerance and lipid metabolism.

AMP-activated protein kinase: implications on ischemic diseases

  • Ahn, Yong-Joo;Kim, Hwe-Won;Lim, Hee-Jin;Lee, Max;Kang, Yu-Hyun;Moon, Sang-Jun;Kim, Hyeon-Soo;Kim, Hyung-Hwan
    • BMB Reports
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    • v.45 no.9
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    • pp.489-495
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    • 2012
  • Ischemia is a blockage of blood supply due to an embolism or a hemorrhage in a blood vessel. When an organ cannot receive oxygenated blood and can therefore no longer replenish its blood supply due to ischemia, stresses, such as the disruption of blood glucose homeostasis, hypoglycemia and hypoxia, activate the AMPK complex. LKB1 and $CaMKK{\beta}$ are essential activators of the AMPK signaling pathway. AMPK triggers proangiogenic effects through the eNOS protein in tissues with ischemic conditions, where cells are vulnerable to apoptosis, autophagy and necrosis. The AMPK complex acts to restore blood glucose levels and ATP levels back to homeostasis. This review will discuss AMPK, as well as its key activators (LKB1 and $CaMKK{\beta}$), as a central energy regulator and evaluate the upstream and downstream regulating pathways of AMPK. We will also discuss how we can control this important enzyme in ischemic conditions to prevent harmful effects in patients with vascular damage.

Etoposide Induces Mitochondrial Dysfunction and Cellular Senescence in Primary Cultured Rat Astrocytes

  • Bang, Minji;Kim, Do Gyeong;Gonzales, Edson Luck;Kwon, Kyoung Ja;Shin, Chan Young
    • Biomolecules & Therapeutics
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    • v.27 no.6
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    • pp.530-539
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    • 2019
  • Brain aging is an inevitable process characterized by structural and functional changes and is a major risk factor for neurodegenerative diseases. Most brain aging studies are focused on neurons and less on astrocytes which are the most abundant cells in the brain known to be in charge of various functions including the maintenance of brain physical formation, ion homeostasis, and secretion of various extracellular matrix proteins. Altered mitochondrial dynamics, defective mitophagy or mitochondrial damages are causative factors of mitochondrial dysfunction, which is linked to age-related disorders. Etoposide is an anti-cancer reagent which can induce DNA stress and cellular senescence of cancer cell lines. In this study, we investigated whether etoposide induces senescence and functional alterations in cultured rat astrocytes. Senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity was used as a cellular senescence marker. The results indicated that etoposide-treated astrocytes showed cellular senescence phenotypes including increased SA-${\beta}$-gal-positive cells number, increased nuclear size and increased senescence-associated secretory phenotypes (SASP) such as IL-6. We also observed a decreased expression of cell cycle markers, including PhosphoHistone H3/Histone H3 and CDK2, and dysregulation of cellular functions based on wound-healing, neuronal protection, and phagocytosis assays. Finally, mitochondrial dysfunction was noted through the determination of mitochondrial membrane potential using tetramethylrhodamine methyl ester (TMRM) and the measurement of mitochondrial oxygen consumption rate (OCR). These data suggest that etoposide can induce cellular senescence and mitochondrial dysfunction in astrocytes which may have implications in brain aging and neurodegenerative conditions.

Ceramide and Sphingosine 1-Phosphate in Liver Diseases

  • Park, Woo-Jae;Song, Jae-Hwi;Kim, Goon-Tae;Park, Tae-Sik
    • Molecules and Cells
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    • v.43 no.5
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    • pp.419-430
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    • 2020
  • The liver is an important organ in the regulation of glucose and lipid metabolism. It is responsible for systemic energy homeostasis. When energy need exceeds the storage capacity in the liver, fatty acids are shunted into nonoxidative sphingolipid biosynthesis, which increases the level of cellular ceramides. Accumulation of ceramides alters substrate utilization from glucose to lipids, activates triglyceride storage, and results in the development of both insulin resistance and hepatosteatosis, increasing the likelihood of major metabolic diseases. Another sphingolipid metabolite, sphingosine 1-phosphate (S1P) is a bioactive signaling molecule that acts via S1P-specific G protein coupled receptors. It regulates many cellular and physiological events. Since an increase in plasma S1P is associated with obesity, it seems reasonable that recent studies have provided evidence that S1P is linked to lipid pathophysiology, including hepatosteatosis and fibrosis. Herein, we review recent findings on ceramides and S1P in obesity-mediated liver diseases and the therapeutic potential of these sphingolipid metabolites.

A research on the conversion systems of Channels (경락(經絡)의 기화체계(氣化體系)에 대한 연구(硏究))

  • Son, Chang-Su;Kim, Yon-Tae;Kim, Gil-Whon;Shin, Heung-Mook
    • Korean Journal of Acupuncture
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    • v.21 no.1
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    • pp.129-147
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    • 2004
  • Objectives and methods : This research aims to study about conversion system of channels. In the present study, we investigated the movement and conversion of channels on the base of three step theory(三才論), Yeak(易), Hado.Laksea(河圖洛書) and five elements motion and six kinds of factors(Six-Qi). Results and Conclusions : The organization of meridian is composed of the following three parts: hand and foot, Yin and Yang, and the viscera and bowals. It is play an important role in energy flow and its conversion. The law governing energy conversion is divided into three groups i.e. taiyin-yangming channel, shaoyin-taiyang channel and jueyin-shaoyang channel group. Those are composed of Deadea(對待) of Six-Qi, making the body homeostasis. Taken together, we suggest that the conversion system of meridian is founded on the unity between the human body and nature which provides the medical workers with a necessary method of thinking in treating diseases.

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Effects of Chestnut Inner Shell Extract on 3T3-L1 Preadipocyte Differentiation (율피 추출물이 3T3-L1 지방전구세포 분화에 미치는 영향)

  • Lee, Seon-Goo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.2
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    • pp.266-271
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    • 2010
  • Obesity occurred by energy imbalance, is increasing regardless of race, sex, age, and related to the metabolic syndrome, diabetes and cardiovascular disease. Since adipose tissue plays a critical role in regulating energy homeostasis, understanding of adipogenesis pathway and finding of regulatory mechanism for adipogenesis can be helpful to manage obesity as well as obesity-related diseases. In this study, to investigate the effects of Chestnut Inner Shell(CIS) extract on the adipogenesis in 3T3-L1 preadipocytes, 3T3-L1 preadipocytes were differentiated with adipogenic reagents for 9 days in the absence or presence of CIS extract ranging from 10 - 100 ${\mu}g/m{\ell}$. The effect of CIS extract on 3T3-L1 differentiation was examined by measuring intracelluar lipid droplet and triglyceride contents. CIS extract remarkably inhibited lipid accumulation(about 45% inhibition at 100 ${\mu}g/m{\ell}$ of CIS extract) and slightly decreased triglyceride contents(about 15% decrease at 100 ${\mu}g/m{\ell}$ of CIS extract) in 3T3-L1 preadipocytes at the concentration showing no cytotoxicity. These results demonstrated that CIS extract significantly inhibit adipogenesis and can be used for the regulation of obesity.