• Title/Summary/Keyword: Leptin receptor

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Effects of Conjugated Linoleic Acid on Adipocyte Secreted Proteins in vitro

  • Ha, Jung-Heun;Ahn, In-Sook;Byun, Jae-Min;Do, Hyung-Ki;Jung, Sun-Young;Jeong, Jae-Hong;Wahle, Klaus W.J.;Park, Kun-Young;Do, Myoung-Sool
    • Preventive Nutrition and Food Science
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    • v.8 no.3
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    • pp.253-259
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    • 2003
  • Conjugated linoleic acid (CLA) is a class of positional, geometric conjugated dienoic isomers of linoleic acid (LA). CLA activates the immune system, protects against tumorigenesis, and reduces the incidence of atherosclerosis. Trans-10, cis-12 CLA has specific effects on lipid metabolism, it has been shown to reduce body fat gain and regulates some adipocyte secreted proteins in vivo and in vitro. Here we report that a CLA mixture affects cytokine secretion from rat primary adipocytes. Rat primary adipocytes were treated with 1 mM, 100 $\mu$M, 1 $\mu$M or 100 nM CLA mixture doses; and leptin, tumor necrosis factor alpha (TNF a ), interleukin-6 (IL-6) and glycerol levels in the medium were measured. Leptin secretion was lower, TNF $\alpha$ secretion higher and IL-6 secretion did not change in response to the CLA mixture. Leptin and TNF $\alpha$ secretions did not change with CLA mixture treatment in a dose-dependent manner. In addition, the CLA mixture did not appear to enhance lipolysis in rat primary adipocytes. In conclusion, our study demonstrates that the decrease in leptin and increase in TNF $\alpha$ secretion in adipocytes treated with CLA mixture may be due to the apoptotic effect and to a reduction in peroxisome proliferator-activated receptor gamma (PPAR ${\gamma}$ ) ligands.

Polysaccharides from Edible Mushroom Hinmogi (Tremella fuciformis) Inhibit Differentiation of 3T3-L1 Adipocytes by Reducing mRNA Expression of $PPAR{\gamma}$, C/$EBP{\alpha}$, and Leptin

  • Jeong, Hye-Jin;Yoon, Seon-Joo;Pyun, Yu-Ryang
    • Food Science and Biotechnology
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    • v.17 no.2
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    • pp.267-273
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    • 2008
  • Water-soluble fraction (WSF) from edible mushroom hinmogi (Tremella fuciformis) were obtained by water extraction, and polysaccharides in the WSF were separated by ethanol precipitation. The inhibitory effects of the polysaccharides on 3T3-L1 adipocyte differentiation were evaluated by the reduction of peroxisome proliferators-activated receptor ${\gamma}$ ($PPAR{\gamma}$) translation, triglyceride accumulation, Oil Red-O staining, and expression levels of $PPAR{\gamma}$, CCAAT/enhancer binding protein a (C/$EBP{\alpha}$), and leptin. The $PPAR{\gamma}$ translation in 3T3-L1 cells was inhibited by the treatment with polysaccharide precipitated by 80% ethanol (P80) which showed highest inhibitory activity among polysaccharides tested. In addition, treatment of P80 to 3T3-L1 cells significantly inhibited the triglyceride accumulation, Oil Red-O staining, and mRNA expression of $PPAR{\gamma}$, C/$EBP{\alpha}$, and leptin in a dose-dependent manner. Based upon these results, P80 from edible mushroom hinmogi shows the inhibitory activity on the differentiation of 3T3-L1 adipocytes. Therefore, it might be employed as a potential anti-obesity material.

The Study for the Relationship of Weight Loss with Plasma Leptin and TNF-α Level in Patients with Chronic Bronchitis and Emphysema (만성기관지염과 폐기종 환자에서 체중감소와 혈중 Leptin 및 TNF-α와의 관계에 대한 연구)

  • Pack, Jong Hae;Park, Ji Young;Park, Hye Jeong;Baek, Suk Hwan;Shin, Kyeong Cheol;Chung, Jin Hong;Lee, Kwan Ho
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.2
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    • pp.199-209
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    • 2003
  • Background : Unexplained weight loss, which commonly occurs in patients with chronic obstructive pulmonary disease(COPD), is important because weight loss is an independent risk factor of mortality and morbidity in these patients. Leptin is known to play an important role in regulating body weight. In addition, the tumor necrosis factor($TNF-{\alpha}$) might also play a potential role in the weight loss experienced in chronic wasting disease. The aim of this study was to determine the influence of plasma leptin and the circulating $TNF-{\alpha}$ system to the difference in the body compositions in patients with COPD. Methods : Spirometry, body composition analysis and the plasma concentrations of leptin, $TNF-{\alpha}$ and a soluble TNF receptor (STNF-R55, -R75) were measured in 31 patients with chronic bronchitis and 10 patients with emphysema. The COPD subtype was classified by the transfer coefficient of carbon monoxide, DLco/VA. Results : The circulating levels of leptin were significantly lower in those patients with emphysema($108.5{\pm}39.37pg/ml$) than those with chronic bronchitis($180.9{\pm}57.7pg/ml$). The circulating levels of sTNF-R55 were significantly higher in the emphysema patients($920.4{\pm}116.4pg/ml$) than in those with chronic bronchitis($803.2{\pm}80.8pg/ml$). There was no relationship between the circulating leptin levels and the activated TNF system in patients with chronic bronchitis and emphysema. However, the circulating leptin levels correlated well with the BMI and fat mass in both patient groups. Conclusion : These results suggest that the weight loss noted in emphysema patients may be associated with the activation of the $TNF-{\alpha}$ system rather than the plasma leptin level.

Analysis of Pine Nut Oil Composition and Its Effects on Obesity (잣기름 성분분석 및 비만 예방효과 연구)

  • Kim, Kyoung Kon;Kang, Yun Hwan;Kim, Dae Jung;Kim, Tae Woo;Choe, Myeon
    • Korean Journal of Food Science and Technology
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    • v.46 no.5
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    • pp.630-635
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    • 2014
  • Pine nut oil (PNO) is well known to impart beneficial effects in overweight individuals, but the mechanisms underlying PNO-mediated weight loss remain unclear. To investigate how PNO promotes weight loss, its composition was determined by gas chromatography coupled with mass spectrometry (GC-MS). In addition, the effects of PNO on cytotoxicity, lipid accumulation, expression of lipid metabolism-related biomarkers, and leptin secretion were assessed in 3T3-L1 cells. GC-MS analyses revealed that PNO contains several components, including linoleic acid, oleic acid, palmitic acid, and stearic acid. Moreover, PNO did not have a cytotoxic effect on 3T3-L1 cells. However, it inhibited the expression of peroxisome proliferator-activated receptor (PPAR) and adipocyte protein 2 (aP2). Finally, PNO significantly increased leptin secretion in a dose-dependent manner. Taken together, these results support the notion that PNO is useful for weight management in overweight individuals.

Effect of Dietary Conjugated Linoleic Acid (CLA) on Abdominal Fat Deposition in Yellow-feather Broiler Chickens and Its Possible Mechanism

  • Zhou, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.12
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    • pp.1760-1765
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    • 2008
  • A total of 60 one-day-old Yellow-feather broiler chickens were allotted into treatment and control groups. The treatment group was fed with the diet supplemented with 3% conjugated linoleic acid (CLA) for 48 d, while control group was fed with the diet supplemented with 3% rapeseed oil. Chickens were slaughtered in each group at the age of 49 d, and the blood and the abdominal adipose tissue were sampled. Serum cLeptin and serum cAdiponectin were measured by ELISA. The total RNA was extracted from adipose tissue to measure the abundance of the chicken growth hormone receptor (cGHR), insulin-like growth factor 1 (cIGF-1), insulin-like growth factor I receptor (cIGF-IR), peroxisome proliferator-activated receptor gamma ($cPPAR{\gamma}$), cAdiponectin and cAdipoIR mRNA by RT-PCR using ${\beta}$-actin as an internal standard. Results showed that the CLA decreased the abdominal fat index by 20.93% (p<0.05). The level of serum cLeptin but not serum cAdiponectin was significantly increased by CLA treatment (p<0.05). CLA down-regulated the relative abundance of cGH-R mRNA and $cPPAR{\gamma}$ mRNA in abdominal adipose tissue by 24.74% (p<0.05) and 66.52% (p<0.01) respectively. However, no differences were found between CLA treatment group and control group (p>0.05) in the relative abundance of cIGF-1, cIGF-IR, cAdiponectin, and cAdipoIR mRNA in abdominal adipose tissue. The data suggested that CLA inhibited abdominal fat deposition in broiler chicken may be determined by decreasing the GHR available for GH, and by inhibiting the differentiation of preadipocytes via down-regulation of $PPAR{\gamma}$, but independent of IGF and (or) GH-IGF pathway or adiponectin action.

Effects of Agastache rugosa on Obesity Via Inhibition of Peroxisome Proliferator-Activated Receptor-Gamma and Reduction of Food Intake (지방합성 인자 조절 및 식이 섭취 감소를 통한 곽향의 항비만 효능)

  • Kim, Young Min;Kim, Mi Hye;Yang, Woong Mo
    • Journal of Korean Medicine for Obesity Research
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    • v.15 no.2
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    • pp.104-110
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    • 2015
  • Objectives: The herb of Agastache rugosa (AR) is a traditional herbal medicine used for colds, vomiting and furuncles. However, there are few reports to investigate the inhibitory effects of AR on obesity. In this study, the effects of AR on high fat diet (HFD)-induced obesity and its mechanism of actions were investigated in experimental animals. Methods: The mice were fed HFD for 4 weeks to induce obesity. After randomly divided into normal fat diet, HFD and AR groups, 200 mg/kg of AR was administrated for 4 weeks with continuous HFD feeding while vehicle was orally treated to HFD group. Food intake and body weight were recorded weekly. Results: Increased body weight by HFD was improved by AR treatment. AR administration inhibited an increase of visceral fat weight as well as adipocyte hypertrophy. Hepatic steatosis was ameliorated in AR-treated mice. In addition, treatment of AR attenuated the expression of adipogenic transcription factor, peroxisome proliferator-activated receptor (PPAR)-gamma in the epididymal adipose tissue. Also the increased serum leptin level by HFD was maintained in AR group, leading to inhibition of food intake. Conclusions: AR treatment showed inhibitory effects on HFD-induced obesity by inhibition of PPAR-gamma and reduction of food intake. AR could be an alternative treatment for obesity.

The comparative study on the anti-obesity effect of Arctium lappa L. roots with and without microwave processing (마이크로파 처리 유무에 따른 우엉뿌리의 항비만 효과 비교 연구)

  • Seo, Seong-Wook;Kim, Min Ju;Kim, Kyoung;Chung, Dong-Min;Shin, Mi-Rae
    • The Korea Journal of Herbology
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    • v.37 no.4
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    • pp.17-29
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    • 2022
  • Objective : The present study comparatively analyzed the anti-obesity effect of Arctium lappa L. roots with and without microwave processing. Methods : Four HFD groups except for the Normal group (n=8) were allocated: Control, microwave-processed dried Arctium lappa L. roots (MAL) extract 400 mg/kg/d (MAL400), MAL extract 800 mg/kg/d (MAL800), and the dried Arctium lappa L. roots (DAL) extract 800 mg/kg/d (DAL800). The efficacy of MAL and DAL was confirmed in terms of the serum biochemical index, protein expressions related to the synthesis of triglyceride (TG) and total cholesterol (TC) and 𝛽-oxidation, and histopathological staining. Results : Both MAL and DAL treatments significantly reduced final body weight and body weight gain. MAL800 treatment significantly reduced serum TG, TC, low-density lipoprotein cholesterol, and leptin levels, but the serum high-density lipoprotein cholesterol and adiponectin concentrations were dramatically increased. In particular, leptin in the MAL800 group was reduced by 14.1% compared with the DAL800 group. Moreover, the MAL800 treatment showed an effect superior to the DAL800 treatment in the reduction of serum TC, the sirtuin 1 (Sirt1) activation, and the inhibition of 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR) gene expression. In particular, unlike the DAL800 treatment, MAL treatment significantly led to the activation of peroxisome proliferator-activated receptor alpha (PPAR𝛼). Subsequently, PPAR𝛼 meaningfully regulated downstream proteins associated with 𝛽-oxidation. Conclusion : These findings suggest that Arctium lappa L. roots with microwave processing effectively ameliorate obesity through the regulation of leptin and TC and the promotion of 𝛽-oxidation compared with Arctium lappa L. roots without microwave processing.

Role of Ghrelin in the Control of Reproductive Endocrine Function (포유류 생식 내분비 기능 조절에서 Ghrelin의 역할)

  • Lee, Sung-Ho
    • Development and Reproduction
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    • v.13 no.4
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    • pp.207-215
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    • 2009
  • Numerous factors can affect the activities of hypothalamus-pituitary-gonad (HPG) hormonal axis, resulting in alteration of reproductive capacity or status such as onset of puberty and menopause. Soon after the finding of leptin, a multifunctional hormone secreted from adipocytes, a close relationship between reproduction and body energy balance have been manifested. Ghrelin, another multifunctional hormone from gastrointestinal tract, is an endogenous ligand of growth hormone secretagogue receptor (GHSR), and is thought to be a counterpart of leptin in the regulation of energy homeostasis. As expected, ghrelin can also modulate the reproductive capacity through the modulation of activities of HPG axis. This paper summarizes the current knowledge on the discovery, gene structures, tissue distribution and roles of ghrelin and GHSRs in mammalian reproduction in particular modulation of reproductive hormone secretion in HPG axis. Like POMC gene expression in pituitary gland, preproghrelin gene can generate a complex repertoire of transcripts which further undergo alternative splicing and posttranslational modifications. Concerning the roles of preproghrelin gene products in the control of body physiology except energy homeostasis, limited knowledge is available so far. Several lines of evidence, however, show the interplay of ghrelin between metabolism and reproduction. In rat and human, the distribution of ghrelin receptor GHSRs (GHSR1a and GHSR1b) has been confirmed not only in the hypothalamus and pituitary which were originally postulated as target of ghrelin but also in the testis and ovary. Expression of the preproghrelin gene in the brain and gonads was also verified, suggesting the local role (s) of ghrelin in HPG axis. Ghrelin might play a negative modulator in the secretions of hypothalamic GnRH, pituitary gonadotropins and gonadal steroids though the action on pituitary is still questionable. Recent studies suggest the involvement of ghrelin in regulation of puberty onset and possibly of menopause entry. It is now evident that ghrelin is a crucial hormomal component in 'brain-gut' axis, and is a strong candidate links between metabolism and reproduction. Opposite to that for leptin, ghrelin signaling is likely representing the 'hunger' state of body energy balance and is necessary to avoid the energy investment into reproduction which has not a top priority in maintaining homeostasis. Further researches are needed to gain a deep insight into the more precise action mechanism and role of ghrelin in reproduction, and to guarantee the successful biomedical applications.

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Characteristics of Individual Growth Curve by Porcine LEPR-derived Microsatellite Polymorphisms (돼지의 Leptin receptor 유전자내 초위성체 다형성에 따른 개체별 성장곡선 특성)

  • Cho, Y.M.;Choi, B.H.;Kim, T.H.;Lee, J.W.;Cheong, I.C.
    • Journal of Animal Science and Technology
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    • v.45 no.6
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    • pp.885-890
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    • 2003
  • This study was conducted to estimate the growth curve parameters of 253 heads of F2 population produced by inter-crossing F1 from Korean Native boars and Landrace sows, and to estimate the effects of Leptin receptor gene(LEPR) on their growth characteristics. Growth curve parameters were estimated from nonlinear regression using Gompertz model individually. Average mature weight and average maturing rate estimated were 179.69${\pm}$4.40kg and 0.3103${\pm}$0.0043, respectively. The effect of sex was insignificant for all the parameters estimated from Gempertz model(p〉.05), and the effect of calving group was significant for mature weight and maximum growth rate at inflection point (p〈.05). The effect of LEPR genotype were significant for all the growth curve parameters(p〈.05). According from the results of the least squares means of growth curve parameters by LEPR genotypes, mature weight and point of inflection were highest in genotype AA in which the maturing rate was the lowest, and were lowest in genotype DD in which maturing rate was the highest, reversely.

Association of Leptin Receptor Lys109Arg and Gln223Arg Polymorphisms with Increased Risk of Clear Cell Renal Cell Carcinoma

  • Mu, Hui-Jun;Zou, Jian;Xie, Ping;Xu, Zhuo-Qun;Ruan, Jun;Yang, Shu-Dong;Yin, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4211-4215
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    • 2014
  • Background: Although roles of genetic polymorphisms of leptin receptor (LEPR) gene in several cancers have been documented, the association between polymorphisms of LEPR and clear cell renal cell carcinoma (CC-RCC) remains unknown. The aim of this study was to explore any relation. Materials and Methods: The study population consisted of 77 patients with CC-RCC and 161 healthy control subjects. Polymorphism analyses of Lys109Arg and Gln223Arg were performed by direct DNA sequencing and PCR-restriction fragment length polymorphism approaches respectively. Results: Comparisons of allelic and genotypic frequencies in Lys109Arg and Gln223Arg showed no significant difference between the cases and controls. However, when evaluating the combined genotype of Lys109Arg and Gln223Arg, risk with GG/GG was increased (OR=1.85, 95%CI=1.04-3.30) and with GA/GG or GG/GA was decreased (OR=0.07, 95%CI=0.01-0.54; OR and 95%CI of the latter could not be calculated for a value of zero). Furthermore, the G-G haplotype frequency of Lys109Arg and Gln223Arg in the cases was higher (OR=1.68; 95%CI=1.02-2.76). In contrast, the A-G and G-A haplotype frequencies in the cases were lower than those in the controls (OR=0.06; 95%CI=0.01 to 0.47; OR and 95%CI of the latter could not be calculated for a value of zero). In addition, the Lys109Arg A allele was in LD with the Gln223Arg A allele (d'=0.9399) in the CC-RCC subjects, but not in the controls. Conclusions: Our data suggest that the GG/GG combined genotype and G-G haplotype of Lys109Arg and Gln223Arg can act as evaluating factors for CC-RCC risk.