• Title/Summary/Keyword: Insulin Action

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The Regulatory Effects of Trans-chalcone on Adipogenesis

  • Han, Younho
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.29-35
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    • 2018
  • It is noted that chalcone derivatives have characteristic diverse pharmacological properties, and that precise evidence has been growing that they could regulate a tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) induced insulin resistance. The purpose of the present investigation is to elucidate the effects of the identified chalcone derivatives on adipogenesis, and to find the underlying mechanism of action in that case. Consequently, we first investigated whether the chalcone derivatives could affect the identified $PPAR{\gamma}$-induced transcriptional activity on the proliferator-activated receptor response elements (PPRE) at target promoters, and find that trans-chalcone most significantly increased the $PPAR{\gamma}$-induced transcriptional activity. Additionally, we confirmed that there were up-regulatory effects of trans-chalcone during the adipogenesis and lipid accumulation, and on the mRNA of adipogenic factors in 3T3-L1 cells. Next, we examined the effect of trans-chalcone on the inhibition induced by $TNF-{\alpha}$ on adipogenesis. To that end, we noted that the treatment with trans-chalcone attenuated the effect of $TNF-{\alpha}$ mediated secretion of various adipokines that are involved in insulin sensitivity. For this reason, we noted that this study clearly demonstrates that trans-chalcone enhanced adipogenesis, in part, by its potent effect on $PPAR{\gamma}$ activation and by its reverse effect on $TNF-{\alpha}$.

Blood Glucose Lowering Activity and Mechanism of Sangbackpitang (SBPT) in db/db Mouse (db/db 마우스에서 상백피탕의 혈당강하 활성 및 기전연구)

  • 이성현;안세영;두호경;정성현
    • YAKHAK HOEJI
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    • v.43 no.6
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    • pp.818-826
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    • 1999
  • Antidiabetic activity and mechanism of Sangbackpitang (SBPT) was examined in db/db mice, which is a spontaneously hyperglycemic, hyperinsulinemic and obese animal model. SBPT and acarbose were administered orally for 4 weeks. Fasting and non-fasting serum glucose, glycated hemoglobin and triglyceride were all reduced when compared between db/db control group and SBPT treated group. At 12th week after birth, SBPT increased an insulin secretion although statistic significance was not seen. Total activities of sucrase, maltase and lactase in SBPT treated group were all decreased when compared to db/db control. On the other hand, sucrase and maltase activities in acarbose treated groups were increased. Effect of SBPT on mRNA expression of glucose transporter(GLUT-4) was also examined. Quantitation of glucose transporter was performed by RT-PCR and in vitro transcription with co-amplification of rat-action gene as an internal standard. Muscular GLUT-4 mRNA expression in SBPT treated group was increased significantly. These results may suggest that SBPT lowered blood glucose ascribing to inhibition of glycosidase-catalyzed reaction and upregulation of muscular GLUT-4 mRNA expression.

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The effect of thalidomide on visceral fat pad mass and triglyceride concentration of the skeletal muscles in rats

  • Kim, Ki-Hoon;Choi, Chang-Bon;Kim, Jong-Yeon
    • Journal of Yeungnam Medical Science
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    • v.35 no.2
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    • pp.213-218
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    • 2018
  • Background: Body fats, especially both of abdominal fat pad mass and skeletal muscle fat content, are inversely related to insulin action. Therefore, methods for decreasing visceral fat mass and muscle triglyceride content may be helpful for the prevention of insulin resistance. Methods: Thalidomide, used for its anti-angiogenic and anti-inflammatory properties, was administered to rats for 4 weeks. A 10% solution of thalidomide in dimethyl sulfoxide was injected daily into the peritoneal cavity as much as 100 mg/kg of body weight. Results: The total visceral fat pad mass in the thalidomide-treated group was 11% lower than in the control group. The size of adipocytes of the epididymal fat pad mass in the thalidomide-treated group was smaller than in the control group. The intraperitoneal thalidomide treatment increased triglyceride concentrations by 16% in the red muscle, but not in the white muscle. Conclusion: The results suggested that intraperitoneal thalidomide treatment inhibited abdominal fat accumulation, and that the free fatty acids in the blood were preferentially accumulated in the red muscle rather than in the white muscle.

Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

  • Lim, Chae Jin;Jeon, Jung Eun;Jeong, Se Kyoo;Yoon, Seok Jeong;Kwon, Seon Deok;Lim, Jina;Park, Keedon;Kim, Dae Yong;Ahn, Jeong Keun;Kim, Bong-Woo
    • BMB Reports
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    • v.48 no.9
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    • pp.501-506
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    • 2015
  • Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506]

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome

  • Wang, Helen H.;Lee, Dong Ki;Liu, Min;Portincasa, Piero;Wang, David Q.H.
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.23 no.3
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    • pp.189-230
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    • 2020
  • The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Anti-diabetic Effect and Mechanism of Korean Red Ginseng in C57BL/KsJ db/db Mice

  • Yuan, Hai-Dan;Shin, Eun-Jung;Chung, Sung-Hyun
    • Journal of Ginseng Research
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    • v.32 no.3
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    • pp.187-193
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    • 2008
  • The present study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng in C57BL/KsJ db/db mice. The db/db mice were divided into three groups: diabetic control group (DC), Korean red ginseng group (KRG, 100 mg/kg) and metformin group (MET, 300 mg/kg), and treated with drugs once per day for 10 weeks. Compared to the DC group, fasting blood glucose levels were decreased by 19.8% in KRG-, 67.7% in MET-treated group. With decreased plasma glucose and insulin levels, the insulin resistance index of the KRG-treated group was reduced by 27.6% compared to the DC group. The HbA1c levels in KRG and MET-treated groups were also decreased by 11.0% and 18.9% compared to that of DC group, respectively. Plasma triglyceride and non-esterified fatty acid levels were decreased by 18.8% and 16.8%, respectively, and plasma adiponectin and leptin levels were increased by 20.6% and 12.1%, respectively, in the KRG-treated group compared to those in DC group. Histological analyses of the liver and fat tissue of mice treated with KRG revealed significantly decreased number of lipid droplets and decreased size of adipocytes compared to the DC group. From the pancreatic islet double-immunofluorescence staining, we observed KRG has increased insulin contents, but decreased glucagon production. To elucidate action mechanism of KRG, effects on AMP-activated protein kinase (AMPK) and its downstream target proteins responsible for fatty acid oxidation and gluconeogenesis were explored in the liver. KRG activated AMPK and acetyl-coA carboxylase (ACC) phosphorylations, resulting in stimulation of fatty acid oxidation. KRG also caused to down regulation of SREBP1a and its target gene expressions such as FAS, SCD1 and GPAT. In summary, our results suggest that KRG exerted the anti-diabetic effect through AMPK activation in the liver of db/db mice.

Effect of JAK-STAT pathway in regulation of fatty liver hemorrhagic syndrome in chickens

  • Zhu, Yaling;Mao, Huirong;Peng, Gang;Zeng, Qingjie;Wei, Qing;Ruan, Jiming;Huang, Jianzhen
    • Animal Bioscience
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    • v.34 no.1
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    • pp.143-153
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    • 2021
  • Objective: To explore the molecular mechanisms of fatty liver hemorrhagic syndrome (FLHS) in laying hens, an experiment was conducted to reveal the differences in histopathological observation and gene expression between FLHS group and normal group. Methods: We compared the histopathological difference using hematoxylin and eosin staining and proceeded with RNA sequencing of adipose tissue to search differentially expressed genes and enriched biological processes and pathways. Then we validated the mRNA expression levels by real-time polymerase chain reaction and quantified protein levels in the circulation by enzyme-linked immunosorbent assay. Results: We identified 100 differentially expressed transcripts corresponding to 66 genes (DEGs) were identified between FLHS-affected group and normal group. Seven DEGs were significantly enriched in the immune response process and lipid metabolic process, including phospholipase A2 group V, WAP kunitz and netrin domain containing 2, delta 4-desaturase sphingolipid 2, perilipin 3, interleukin-6 (IL-6), ciliary neurotrophic factor (CNTF), and suppressor of cytokine signaling 3 (SOCS3). And these genes could be the targets of immune response and be involved in metabolic homeostasis during the process of FLHS in laying hens. Based on functional categories of the DEGs, we further proposed a model to explain the etiology and pathogenesis of FLHS. IL-6 and SOCS3 mediate inflammatory responses and the satiety hormone of leptin, induce dysfunction of Jak-STAT signaling pathway, leading to insulin resistance and lipid metabolic disorders. Conversely, CNTF may reduce tissue destruction during inflammatory attacks and confer protection from inflammation-induced insulin resistance in FLHS chickens. Conclusion: These findings highlight the therapeutic implications of targeting the JAK-STAT pathway. Inhibition of IL6 and SOCS3 and facilitation of CNTF could serve as a favorable strategy to enhance insulin action and improve glucose homoeostasis, which are of importance for treating obesity-related disorders for chickens.

Bovine Growth Hormone and Milk Fat Synthesis: from the Body to the Molecule - Review -

  • Kim, W.Y.;Ha, J.K.;Han, In K.;Baldwin, R.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.4
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    • pp.335-356
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    • 1997
  • Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

Distribution of Insulin-Like Growth Factor-Binding Proteins(IGFBPs) and IGFBP-3 Proteolysis in Noninsulin-Dependent Diabetes Mellitus Serum (인슐린 비의존형 당뇨병 환자의 혈청 중 Insulin-Like Growth Factor-Binding Proteins(IGFBPs)의 분포 및 IGFBP-3의 분해)

  • Lee, Hwa-Jin;Kim, Sung-Hyun;Kwon, Mi-Jin;Nam, Taek-Jeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.2
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    • pp.285-290
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    • 1997
  • The insulin-like growth factors(IGFs) are bound to several binding proteins(IGFBPs) that appear to regulate IGF transport, receptor binding, and its action. The concentration of these peptides are altered by catabolic conditions. To determine IGF-I and IGFBP levels in noninsulin-dependent diabetes mellitus (NIDDM), sera was obtained from 5 patients and 7 controls. Serum levels of IGF-I in NIDDM were lower than those in either of the controls. By western immunoblot analysis, especially IGFBP-1 levels are increased, whereas IGFBP-3 levels decreased and their fragments was increased in NIDDM serum. IGFBP-3 proteolytic activity in NIDDM sera was inhibited by phenylmethylsulfonylfluoride (PMSF), aprotinin, and ethylenediaminetetraacetic acid(EDTA). This pattern of inhibition was consistent with a metal-dependent serine protease. By gelatin zymography, these proteolytic enzymes were identified as the size of 97 and 69 kDa. IGFBP-1, which is primarily insulin regulated, was increased in NIDDM and may modulate circulating IGF-I levels by regulating capillary passage of IGF-I. IGFBP-3 proteolysis markedly reduces its affinity for the IGFs, particularly for IGF-I. This accelerates their kinetics of dissociation, thereby increasing the proportions of IGF-I in free form and its availability to the cells.

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Beneficial Effect of the Combination of Oral Administration and Herbal -Acupuncture Stimulation with Several Herb-combind Prescription on Streptozotocin-Induced Diabetic Rats (한약복합처방(韓藥複合處方) 약침(藥鍼) 및 경구투여(經口投與)가 Streptozotoin에 의한 흰쥐의 당뇨병(糖尿病)과 항산화능(抗酸化能)에 미치는 영향)

  • Park, Sa-hyun;Cho, Su-in;Chae, Woo-seok;Cho, Myung-rae
    • Journal of Acupuncture Research
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    • v.22 no.1
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    • pp.1-11
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    • 2005
  • Objective : The present study was carried out to investigate the preventive effect of Several Herb-combind Prescription(SHP) on Streptozotocin (STZ) -induced Diabetes mellitus. Methods : SHP was given to rats with the combination of oral administration and herbal-acupuncture stimulation. The experimental animals were divided into 3 groups : normal group of rats, control group of STZ-induced diabetic rats, sample group with SHP treatment. In vitro test of SHP showed ${\alpha}$-glucosidase inhibition, DPPH radical scavenging activity and inhibition of lipid peroxidation. Experimental diabetes was induced by the injection of STZ(60mg/kg) to the rat via the peritoneum. The effect of SHP on STZ-induced diabetes was observed by measuring the seum level of insulin, glucose, triglyceride, total cholesterol and lipid peroxides. Hepatic activities of catalase and reduced glutathione were examined and insulin granule was observed by immunohistochemical examination. Result : STZ caused hyperglycemia and hypoinsulinemia by a selectively destroying pancreatic ${\beta}$-cell. SHP treatment protected them from the hyperglycemia and hypoinsulinemia. STZ induced increase of serum triglyceride lowered by SHP treatment. And by SHP treatment, pancrease showed a big area with positive immuno-reactivity for presence of insulin with many insulin granules distributed in the ${\beta}$-cells in the islets of Langerhans. Contusions : The SHP treatment showed protective effect on diabetic rat model, and action mechanism of the effect was thought to be concerned with anti-oxidative stress.

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