• Title, Summary, Keyword: Leptin

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Leptin potentiates Prevotella intermedia lipopolysaccharide-induced production of TNF-$\alpha$ in monocyte-derived macrophages

  • Kim, Sung-Jo
    • Journal of Periodontal and Implant Science
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    • v.40 no.3
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    • pp.119-124
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    • 2010
  • Purpose: In addition to regulating body weight, leptin is also recognized for its role in the regulation of immune function and inflammation. The purpose of this study was to investigate the effect of leptin on Prevotella (P.) intermedia lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-$\alpha$ production in differentiated THP-1 cells, a human monocytic cell line. Methods: LPS from P. intermedia ATCC 25611 was prepared by the standard hot phenol-water method. THP-1 cells were incubated in the medium supplemented with phorbol myristate acetate to induce differentiation into macrophage-like cells. The amount of TNF-$\alpha$ and interleukin-8 secreted into the culture medium was determined by enzyme-linked immunosorbent assay (ELISA). TNF-$\alpha$ and Ob-R mRNA expression levels were determined by semi-quantitative reverse transcription-polymerase chain reaction analysis. Results: Leptin enhanced P. intermedia LPS-induced TNF-$\alpha$ production in a dose-dependent manner. Leptin modulated P. intermedia LPS-induced TNF-$\alpha$ expression predominantly at the transcriptional level. Effect of leptin on P. intermedia LPS-induced TNF-$\alpha$ production was not mediated by the leptin receptor. Conclusions: The ability of leptin to enhance P. intermedia LPS-induced TNF-$\alpha$ production may be important in the establishment of chronic lesion accompanied by osseous tissue destruction observed in inflammatory periodontal disease.

The Effects of Polymannuronates on Leptin in 3T3-L1 Adipocytes (3T3-L1 지방세포 내의 Leptin에 미치는 Polymannuronates의 영향)

  • KIM In-Hye;NAM Teak-Jeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.5
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    • pp.372-379
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    • 2004
  • This study evaluated polymanuronates on the differentiation of 3T3-L1 adipocytes. Polymannuronates increased glucose utilization and reduced the accumulation of triglycerides in the cells. The differentiation showed the same results as Oil red O staining. Also, the polymannuronates inhibited GPDH activity as a result of the restrained adipogenesis promotion process in 3T3-L1 adipocytes. The addition of the differentiation promotion factor to 3T3-L1 promoted the differentiation of adipocytes and increased the expression of the leptin level. However the addition of polymannuronates inhibited differentiation of adipocytes and the leptin secretion level in cells by checking the leptin protein level in the culture media. As well as this, it also inhibited the transcriptional mechanism and leptin mRNA expression. These results suggest that the addition of polymannuronates improves the physiological function of 3T3-L1 cells by reducing the accumulation of triglyceride and GPDH activity, and the repressing expression of leptin at a molecular level.

Leptin, adiponectin levels, and thyroid hormones in normal and obese dogs

  • Lee, Sun-Hee;Lim, Soo-Jung;Park, Hyung-Jin;Song, Kun-Ho
    • Korean Journal of Veterinary Research
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    • v.54 no.3
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    • pp.165-169
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    • 2014
  • The present study compared leptin, adiponectin, and thyroid hormone concentrations in normal and obese dogs, and evaluated the association between leptin and adiponectin concentrations and thyroid function. The serum leptin, adiponectin, thyroid-stimulating hormone (TSH), total thyroxine (tT4), free thyroxine (fT4), triiodothyronine (T3), and cortisol concentrations were measured in 18 normal dogs (body condition score [BCS]: 4-5/9) and 16 obese dogs (BCS: 8-9/9). Leptin and T3 concentrations were higher in the obese group than the normal weight group (p < 0.01 and p < 0.05, respectively). In both groups, the T3 and leptin concentrations were correlated (r = 0.370, p < 0.05), as were the TSH and fT4 and adiponectin concentrations (r = -0.373, p < 0.05 and r = 0.369, p < 0.05, respectively). In the normal weight group, the TSH and fT4 concentrations were correlated with the adiponectin concentrations (r = -0.528, p < 0.05 and r = 0.482, p < 0.05, respectively). The results of the present study suggest that leptin and T3 concentrations are significantly higher in obese dogs than normal weight dogs, and the serum T3 and leptin concentrations are positively correlated.

Serum Leptin Levels and Changes in Body Weight and Obesity Index in Gwacheon Elementary School Children (과천지역 초등학생의 Leptin 수준과 열량섭취, 체중 및 비만도 변화와의 관계)

  • Kim, In-Kyoung;Kang, Jae-Heon;Song, Ji-Hyun
    • Journal of Nutrition and Health
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    • v.40 no.8
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    • pp.736-744
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    • 2007
  • Leptin, as an adipocyte-derived hormone, is an important regulator of food intake and energy expenditure. In the cross-sectional study, leptin was shown to be positively related to body adiposity and metabolic disorders in adults. However, there were very few studies which reported the leptin as a predictor of weight gain over time. We examined whether serum leptin can be used as an indicator of the present and 1-year past weight status in very young children. First grade students from elementary schools in Gwacheon City were enrolled in the study since 2005. The study subjects(total 375 students; 195 boys and 180 girls) participated in the investigation of both 2005 and 2006. Physical examinations including height, weight, waist circumference were done. To examine the prevalence of obesity, obesity index was used. Serum leptin was measured, and their nutritional status was also evaluated based on 3-Day dietary records. Serum leptin levels were strongly positively related with the value of the present BMI and with the value of the BMI one year before. We found no association with leptin levels and amount of energy intake and macronutrient intake in this children population. Children were divided into three groups according to leptin tertiles. The highest leptin tertile group showed highest prevalence of obesity in year 2006 as well as in year 2005. Serum leptin levels can reflect the weight status now and as well as 1-year before. Possibly serum leptin levels can predict the weight gain of year later. Without an action against the obesity on children with high leptin level, those children would maintain the excess adiposity growth and progress into the obesity-related metabolic disorders. Further studies are needed to predict the obesity as early as possible and preventive system then after.

A Study on Relationship of Serum Leptin Levels with Body Weight, Body Mass Index, and Percent Body Fat in the Mothers and Their Infants (산모와 영아의 혈청 렙틴 농도와 체중, 체질량지수, 체지방율과의 상관관계에 관한 연구)

  • Park, Jin-Hee;Bae, Jong-Woo;Chun, Ho-Nam;Choue, Ryo-Won
    • Journal of Nutrition and Health
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    • v.40 no.1
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    • pp.49-57
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    • 2007
  • To estimate whether serum leptin has any effects on body composition during the lactational and postnatal periods, we investigated the relationship of serum leptin levels and anthropometric parameters at right after delivery and 16 weeks after delivery in mothers and their infants. Subjects who signed the concent form, participated in this study were recruited from K university hospital. Characteristics of the subjects (age; $31.0{\pm}4.2$ yr, gestation period; $39.5{\pm}1.0$ wk) were investigated and anthropometric parameters (weight, height, body mass index and percent body fat for mothers, and weight, height, head circumference, chest circumference, and Kaup index for infants) were measured. Serum leptin levels of mothers and their infants also measured. Mean maternal serum leptin levels were $9.9{\pm}8.2ng/ml$ and $9.1{\pm}7.2ng/ml$ at right after delivery and 16 weeks after delivery, respectively showing no significant differences. Mean infant's serum leptin levels at birth $(1.8{\pm}0.4ng/ml)$ were significantly lower than that of at 16 weeks after birth $(4.2{\pm}0.8ng/ml)$ (p < 0.001). Leptin levels of male infants were not different from those of female infants. There were no correlations between the maternal serum leptin levels with their body weight, percent body fat after delivery. However, significant correlations were found between maternal serum leptin levels with their body weight, BMI, percent body fat at 16 weeks after delivery (r = 0.80, p < 0.01, r = 0.90, p < 0.001; r = 0.83, p < 0.01, respectively). There were no correlations between the infant's serum leptin levels and their weight, height, head circumference, and chest circumference. No significant relations were also found between maternal serum leptin levels with those of their infants. As a conclusion, maternal serum levels of leptin should be used with a caution to estimate their infant's leptin levels as well as their anthropometric parameters. Further researches are needed to examine the relationship among the leptin levels of mother's serum, breast milk, placenta, and infant's serum.

Increased Serum Leptin Levels and Leptin mRNA Gene Expression by Zinc Depletion in Rats

  • Lee, Soo-Lim;Kim, Yang-Ha;Kwon, Soon-Tae;Kwun, In-Sook
    • Nutritional Sciences
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    • v.5 no.4
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    • pp.190-196
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    • 2002
  • Zinc deficiency has been shown to result in poor appetite, causing anorexia. However, the role of zinc in the regulation of food intake is not well understood. In the present study, we hypothesized that zinc deficiency dysregulates circulating leptin level and leptin mRNA gene expression, and that whether these changes were occuring as a direct result of, or as a compensatory effect of zinc deficiency in rats. After an adaptation period of 4 weeks, Sprague Dawley rats were provided with three different level of zinc, as one week of a Zn-adequate (30 mg/kg) diet, then two weeks of a Zn-depletion (1 mg/kg ), and finally by two weeks of a Zn-repletion (50 mg/kg) diet. At the end of each dietary experimental period, one third of the 26 rats were killed. Zinc levels of blood subfractions (plasma, yee blood cells and mononuclear cells) and in the liver were substantially decreased, despite the fact that food intake was not substantially decreased during the Zn-depletion period. Serum leptin concentration was significantly increased during the zinc depletion period. Leptin mRNA in adipose tissue was also shown to be highly expressed during the Zn-depletion period. Presumably, increased leptin level and leptin mRNA induction during Zn-depletion conditions may be the cause of lowered appetite which is the common symptom of Zn-deficiency. In conclusion, These increases in circulating leptin levels and in leptin gene expression would be the direct result of, rather than the compensatory effect of, zinc deficiency.

The Study of Relationship among Serum Leptin, Nutritional Status, Serum Glucose and Lipids of Middle-school Girls (일부 사춘기 여중생의 혈청 Leptin 함량과 영양소섭취상태 및 혈당, 혈청지질과의 상관관계 연구)

  • 김미현;승정자
    • Journal of Nutrition and Health
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    • v.33 no.1
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    • pp.49-58
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    • 2000
  • The purpose of this study was to investigate the relationship among urn leptin, nutritional status, and urn lipids, glucose of 99 middle school girls residing in Kyluggi-do, Korea. Subjects were assigned to one of three groups such as underweight(BMI < 20, n=38), normal(20$\leq$BMI<25, n=36) and over weight(BMI$\geq$25, n=25) groups. The nutritional status of the subjects was evaluated by anthropometric measurements, questionnaires, 24-hr dietary recalls and blood anal),sis. The results were as follows : The mean age, body weight, height and BMI were 13.93 years, 55.19kg, 158.40cm and 21.96kg/㎡ respectively. The mean menarche age of the subjects was 12.64 years and the mean daily energy intake was 94.22% off RDA for Koreans. The energy ratio from carbohydrate fat and protein was 63: 24: 13. Underweight group showed the lowest intakes of oils and fats among three groups(p<0.05). The mean serum levels of leptin, glucose, total cholesterol, HDL-cholesterol. LDL-cholesterol and triglyceride were 10.57ng/ml 78.80mg/dl, 12.29mg/dl, 48.07mg/dl, 93.50mg/dl and 78.61mg/d1, respectively. The mean atherogenic index was 2.37. There were significant increases in serum leptin, glucose, LDL-cholesterol, triglyceride and atherogenic index of subjects with increases in their BMIs. Serum leptin showed a significantly positive correlation with BMI(p<0.001), body fat percent(p<0.001). When BMI was adjused, serum leptin showed a significantly positive partial correlations with intakes of animal protein(p<0.05), milks and animal foods(p<0.05), Serum leptin showed a significantly positive correlation with serum glucose(p<0.05) total cholesterol(p<0.01), LDL-cholesterol(p<0.001), triglyceride(p<0.001) and atherogenic index(p<0.001), however, it had significantly negative correlations with HDL-cholesterol(p<0.05). Therefore, these results suggest that the increase of serum levels of leptin may elevate the risk of cardiovascular disease and lipids and some nutrient intakes may be related with serum leptin levels. (Korean J Nutrition 33(1) : 49-58, 2000)

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Expression of Leptin Receptor at Implantation Sites Compared to Interimplantation Sites in the Mouse Uterus

  • Yoon, Se-Jin;Park, Chang-Eun;Shin, Chang-Sook;Lee, Kyung-Ah
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • pp.23-25
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    • 2001
  • 1. Leptin itself was not expressed in mouse uterine tissues. 2. Leptin receptors were not expressed in nonpregnant and little expressed in 3.5 day of pregnant uterine tissues. However, there was a signal in 4.5 and 5.5 day of tissues. 3. The expression level of leptin receptor variants in the implantation sites at around the time of initial embryo attachment (day 4.5 of pregnancy) and during the actual implantation period (day 5.5 of pregnancy) was much lower than that in the interimplantation 4. Finding of the differential expression of leptin receptors in implantation sites compared to interimplantation sites suggests that leptin - leptin receptor system may be one of the delicate regulators in the molecular mechanism of the implantation process.

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Saccharomyces cerevisiae에서의 비만 억제용 재조합 단백질 leptin 생산 연구

  • Gang, Hwan-Gu;Lee, Chung-Yeol;Yun, Ji-Seon;Kim, Won-Cheol;Park, Hyeong-Su
    • 한국생물공학회:학술대회논문집
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    • pp.779-781
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    • 2001
  • Human leptin is a 16kDa protein and is known to influence body weight control. It is composed of 146 amino acids. In this study, human leptin gene was obtained from homosapiens leptin mRNA using RT-PCR. And leptin gene was inserted into secretion vectors and Saccharomyces cerevisiae was transformed. In flask culture, Saccharomyces cerevisiae transformant showing high leptin expression titre was selected and with the best transformant, fed-batch fermentation and purification was optimized. As a result, about 2 g/L of leptin was expressed and the yield of purification was about 80%.

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Leptin in Chickens - a Review

  • Choi, Yang-Ho
    • Proceedings of the Korea Society of Poultry Science Conference
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    • pp.8-16
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    • 2005
  • Leptin, the product of the ob gene, is primarily produced and released from adipocytes and acts on the hypothalamus to decrease food intake and increase energy expenditure. Defect in leptin or leptin receptors results in severe metabolic syndromes such as obesity, diabetes, and hypertension Evidence suggests that leptin plays beyond a satiety factor; in fact, it is a pluripotent player In regulation of numerous body functions. Although its actions have been relatively well studied in mammals scanty data are available in birds. In this article, recent advances in understanding of the roles of leptin in chicken physiology are reviewed with the focus on the effects on food intake, lipid metabolism, development and reproduction, and stress.

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