• 생명과학회지
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• 제17권5호
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• pp.687-693
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• 2007

사람의 섬유아세포인 GM10을 사용하여 glucose의 배양조건에 다른 물질대사 및 IGFBP-3 발현을 살펴본 결과, glucose 농도에 따른 glucose 소비와 triglyceride 축적 수준은 고농도 glucose 배양 조건에서 증가한 반면, 총 단백질 함량은 고농도 glucose배양 조건에서 시간의 경과에 따라 감소하였다. 또한 고농도 glucose 배양 조건에서 5일 동안 배양한 세포 배양액내의 유리아미노산 함량은 저농도보다 고농도 glucose 배양 조건에서 높게 나타났다. IGFBP-3 단백질 수준과 mRNA수준은 저농도 glucose배양 조건에서 증가하였으나, IGFBP-3 단백질 분해효소에 따른 영향은 없었다. 이상의 결과에서 glucose 배양조건에 따른 물질대사는 부분적으로 세포를 이용한 당뇨병 모델 실험에서 in vivo와 같은 결과를 얻지 못하였지만, IGFs와 같은 세포 성장인자에 대한 연구를 통해 세포수준의 당뇨병 모델화가 가능하다고 여겨진다.

• Journal of Nutrition and Health
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• 제35권2호
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• pp.192-200
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• 2002

Conjugated linoleic acid (CLA) is a collective term for positional and geometric isomers of octadecadienoic acid in which the double bonds are conjugated. CLA has anticancer activity in a variety of animal cancer models, and cis-9, trans-11 (c9t11) and trans-10, cis-12(t10c12) CLA are the most predominant isomers present in the synthetic preparations utilized in these animal studies. To compare the ability of c9t11, t10c12 and an isomeric mixture of CLA to inhibit TSU-Prl cell growth, cells were incubated in a serum-free medium with various concentrations of these fatty acids. The isomeric mixture inhibited cell growth in a dose-dependent manner (1-3 $\mu$M) with a 41 $\pm$ 1% inhibition observed at 3 $\mu$M concentration after 48 hours. T10c12 also inhibited cell proliferation in a dote-dependent manner, However, the efficacy and potency of this isomer was much greater than that of the isomeric mixture with a 49 $\pm$ 2% inhibition observed at 0.3 $\mu$M concentration after 48 hours. By contrast, c9t11 slightly increased cell proliferation. To determine whether the growth-inhibiting effect of CLA is related to the changes in production of insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) by these cells, serum-free conditioned media were collected. Immunoblot analysis of conditioned media using a monoclonal anti-IGF-II antibody showed that both the isomeric mixture and t10c12 inhibited secretion of both mature 7,500 Mr and higher Mr forms of pro IGF-II, whereas c9t11 had no effect. Ligand blot analysis with 125I-IGF-II revealed the presence of two types of IGFBPs : 24,000 Mr IGFBP-4 and 30,000 Mr IGFBP-6. The production of IGFBP-4 slightly decreased at the highest concentrations of the isomeric mixture and t10c12. These results indicate that CLA inhibits human prostate cancer cell growth, an effect largely due to the action of t10c12. The growth inhibition may result, at least in part, from decreased production of IGF-II and IGFBP-4 by these cells.

• 한국수산과학회지
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• 제45권5호
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• pp.423-429
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• 2012

This study evaluated the effects of adding sea mustard Undaria pinnatifida glycoprotein to the diet of juvenile olive flounder Paralichthys olivaceus on its growth, and levels of insulin-like growth factor I (IGF-I), IGF binding proteins (IGFBPs), and interleukins. Three experimental diets (U0, U0.5, and U1.0) were formulated that contained different amounts of an extract of U. pinnatifida (0, 0.5, and 1.0%, respectively). Experimental groups were established in triplicate (30 fish/group) and fed for 12 weeks. The experimental group fed 1.0% added U. pinnatifida glycoprotein had the greatest rate of weight gain, which differed significantly from the other experimental groups. SDS-PAGE of the plasma IGF-I and muscle protein showed that the experimental groups taking U. pinnatifida glycoprotein had significantly more IGF-I and a ca. 200 kDa protein, as compared to the control group. In addition, the amount of IGFBP-3 at ca. 43 kDa increased in the group given the U. pinnatifida extract, as compared to the control group. The interluekin-2, -4, -6, and -12 levels paralleled the level of growth factor in the groups given the U. pinnatifida extract. In conclusion, supplementing the diet of olive flounder with U. pinnatifida glycroprotein improved its growth and immunity.

• Tuberculosis and Respiratory Diseases
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• 제50권5호
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• pp.549-556
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• 2001

연구배경 : 세포성장에 관여하는 여러 growth factor중 IGF-I은 IGF-IR와 결합하여 세포증식을 유발하는 mitogen으로 알려져 있다. 대부분의 정상세포 및 암세포는 IGFBPs을 분비하는데 이들은 IGF-I과 결합하여 IGF-I의 세포증식 효과를 증가 혹은 억제시킨다. 마우스 폐암세포주 (3LL)에서 IGF-I이 세포성장에 미치는 효과를 보고, 3LL 세포에서 분비되는 IGFBP을 추출 확인하고, IGFBPs이 세포 성정에 미치는 영향을 관찰하였다. 방 법 : 마우스 폐암세포주 (3LL)를 이용하여, IGF-I을 투여하여 세포성장을 MTT assay로 측정하였고, 3LL에서 분비되는 IGFBP을 추출하여 Western ligand blot 및 western immunoblot으로 확인하였다. 또한 분비된 IGFBP이 세포성장에 미치는 영향을 보기위해, anti-IGFBP antibody을 첨가하여 이의 기능을 억제하여 세포성장에 관한 기능을 관찰하였다. 결 과 : IGF-I은 serum free media에서 3LL 세포성장을 증가시켰다. 3LL 세포는 IGFBP-4를 생성하는 것을 확인하였고, anti-IGFBP-4 antibody를 첨가시 세포성장이 증가된 소견이 관찰되어 IGFBP-4는 세포증식을 억제하는 기능을 가지고 있음을 간접적으로 알 수 있었다. 결 론 : 이상의 실험 결과로 3LL 마우스 폐암세포에서 IGF-I은 세포성장을 증가시키며, 3LL에서 생성된 IGFBP-4는 세포증식을 억제하는 기능을 가지고 있다는 것을 관찰하였다. 향후 IGF-I과 IGFBPs이 암 성장에 미치는 기전과 임상적 적용에 대한 연구가 필요하리라 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제17권2호
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• pp.157-162
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• 2013

Insulin-like growth factor binding proteins (IGFBPs) are important components of insulin growth factor (IGF) signaling pathways. One of the binding proteins, IGFBP-5, enhances the actions of IGF-1, which include the enhanced proliferation of smooth muscle cells. In the present study, we examined the expression and the biological effects of IGFBP-5 in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). The levels of IGFBP-5 mRNA and protein were found to be higher in the VSMC from SHR than in those from WKY. Treatment with recombinant IGFBP-5-stimulated VSMC proliferation in WKY to the levels observed in SHR. In the VSMCs of WKY, incubation with angiotensin (Ang) II or IGF-1 dose dependently increased IGFBP-5 protein levels. Transfection with IGFBP-5 siRNA reduced VSMC proliferation in SHR to the levels exhibited in WKY. In addition, recombinant IGFBP-5 significantly up-regulated ERK1/2 phosphorylation in the VSMCs of WKY as much as those of SHR. Concurrent treatment with the MEK1/2 inhibitors, PD98059 or U0126 completely inhibited recombinant IGFBP-5-induced VSMC proliferation in WKY, while concurrent treatment with the phosphatidylinositol-3 kinase inhibitor, LY294002, had no effect. Furthermore, knockdown with IGFBP-5 siRNA inhibited ERK1/2 phosphorylation in VSMC of SHR. These results suggest that IGFBP-5 plays a role in the regulation of VSMC proliferation via ERK1/2 MAPK signaling in hypertensive rats.

• 한국영양학회:학술대회논문집
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• 한국영양학회 1995년도 추계학술대회 초록
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• pp.11-34
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• 1995

Growth hormone (GH) plays a key role in regulating postnatal growth and can stimulate growth of animals by acting directly on specific receptors on the plasma membrane of tissues or indirectly through stimulating insulin-like growth factor (IGF)-I synthesis and secretion by the liver and other tissues. IGF-I and IGF-Ⅱ are polypeptides with structural similarity with proinsulin that stimulate cell proliferation by endocrine, paracrine and autocrine mechanisms. The initial event in the metabolic action of IGFs on target cells appears to be their binding to specific receptors on the plasma membrane. Current evidence indicates that the mitogenic actions of both IGFs are mediated primarily by binding to the type I IGF receptors, and that IGF action is also mediated by interactions with IGF-binding proteins (IGFBPs). Six distinct IGFBPs have been identified that are characterized by cell-specific interaction, transcriptional and post-translational regulation by many different effectors, and the ability to either potentiate or inhibit IGF actions. Nutritional deficiencies can have their devastating consequence during growth. Although IGF-I is the major mediator of GH's action on somatic growth, nutritional status of an organism is a critical regulator of IGF-I and IGFBPs. Various nutrient deficiencies result in decreased serum IGF-I levels and altered IGFBP levels, but the blood levels of GH are generally unchanged or elevated in malnutrition. Effects of protein, energy, vitamin C and D, and zinc on serum IGF and IGFBP levels and tissue mRNA levels were reviewed in the text. Multiple factors are involved in the regulation of intestinal epithelial cell growth and differentiation. Among these factors the nutritional status of individuals is the most important. The intestinal epithelium is an important site for mitogenic action of the IGFs in vivo, with exogenous IGF-I stimulating mucosal hyperplasia. Therefore, the IGF system appears to provide and important mechanism linking nutrition and the proliferation of intestinal epithelial cells. In order to study the detailed mechanisms by which intestinal mucosa is regulated, we have utilized IEC-6 cells, an intestinal epithelial cell line and Caco-2 cells, a human colon adenocarcinoma cell line. Like intestinal crypt cells analyzed in vivo or freshly isolated intestinal epithelial cells, IEC-6 cells and Caco-2 cells possess abundant quatities of both type Ⅰ and type Ⅱ IGF receptors. Exogenous IGFs stimulate, whereas addition of IGFBP-2 inhibits IEC-6 cell proliferation. To investigate whether endogenously secreted IGFBP-2 inhibit proliferation, IEC-6 cells were transfected with a full-length rat IGFBP-2 cDNA anti-sense expression construct. IEC-6 cells transfected with anti-sense IGFBP-2 protein in medium. These cells grew at a rate faster than the control cells indicating that endogenous IGFBP-2 inhibits proliferation of IEC-6 cells, probably by sequestering IGFs. IEC-6 cells express many characteristics of enterocyte, but do not undergo differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation after reaching confluency. We have demonstrated that Caco-2 cells produce IGF-Ⅱ, IGFBP-2, IGFBP-3, and an as yet unidentified 31,000 Mr IGFBP, and that both mRNA and peptide secretion of IGFBP-2 and IGFBP-3 increased, but IGFBP-4 mRNA and protein secretion decreased after the cells reached confluency. These changes occurred in parallel to and were coincident with differentiation of the cells, as measured by expression of sucrase-isomaltase. In addition, Caco-2 cell clones forced to overexpress IGFBP-4 by transfection with a rat IGFBP-4 cDNA construct exhibited a significantly slower growth rate under serum-free conditions and had increased expression of sucrase-isomaltase compared with vector control cells. These results indicate that IGFBP-4 inhibits proliferation and stimulates differentiation of Caco-2 cells, probably by inhibiting the mitogenic actions of IGFs.

• Asian-Australasian Journal of Animal Sciences
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• 제8권1호
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• pp.51-58
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• 1995

To examine whether colostral growth factors are transferred to the general circulation, concentrations of plasma cortisol, insulin, prolactin, growth hormone, insulin-like growth factors(IGFs) -I and -II, IGF-binding proteins(IGFBPs) and total protein were measured in newborn calves fed colostrums, milk of milk replacer before and after feeding at 12 h intervals during the first two days after birth. Plasma protein concentrations increased with time after than in milk- or milk replacer-fed calves. The mean protein concentration was greater in colostrum-fed than in milk- or milk replacer-fed calves. Plasma cortisol levels transiently declined after each feeding regardless of the type of diet, while insulin levels tended to increase. Mean concentrations of these hormones did not differ between dietary groups, nor did they change with time after birth. Plasma concentrations of prolactin and growth hormone did not differ between dietary groups and also did not change with time after birth or after feeding. Concentrations of IGF-I and IGF-II transiently increased at the second feeding period, but these, as well as plasma IGFBP profiles, were not different between groups or before and after feeding. Results did not indicate significant transfer of colostral growth factors across the newborn ruminant small intestine.

• Journal of Animal Science and Technology
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• 제46권4호
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• pp.563-570
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• 2004

Insulin-like growth factors(IGF)s-I과 -II ligands와 이들의 receptors 및 6종류의 IGF-binding proteins(IGFBPs)로 구성된 IGF systim은 여러 종류의 세포의 생존, 증식 및 분화에 있어서 매우 중요한 역할을 한다. 리튬은 in vitro에서 여러 종류의 세포의 생존과 증식의 조절제로 알려져 있다. 본 연구는 IGF-I, IGF-I receptor 및 IGF carrier로서 주로 IGFBP-3를 발현하는 rat C6 glioma cell에서 LiCl로 유도된 세포 생존 및 증식의 변화와 IGF system components의 발현간의 관계를 구명하고자 수행되었다. 10%혈청을 함유하는 배양액에서 0, 2mM, 혹은 5mM LiCl을 첨가하여 C6 cell을 24시간 배양했을 시 세포의 생존률과 세포 수는 리튬 첨가에 의해 영향을 받지 않았다. 그러나 72시간 배양 했을 때 C6 cell은 명백히 리튬의 첨가수준에 따라 반응하였다. 0, 2m, 5mM LiCl 첨가수준에서 72시간 배양한 C6 cell은 각각 전형적인 세포분열, 세포분열 중지 및 세포사멸 양상을 보였다. 더욱이 사멸돼가는 세포는 reverse transcription-polymerase chain reaction으로 조사한 IGF-I, IGF receptor 및 IGFBP-3의 발현수준이 저하되었다. 흥미롭게도 혈청을 첨가하지 않은 배양조건 하에서 IGFBP-3에 대한 antisense oligodeoxyribonucleotide를 10${\mu}M$ 수준의로 첨가하여 배양했을 때도 표적 mRNA는 물론 세포 수도 줄었다. 종합하자면, C6 cell에서 리튬의 독성 효과의 일부는 이 제제에 의한 IGF system components의 발현 억제 효과에 의해 매개될 소지가 크다. 이러한 관점에서 IGRBP-3는 적어도 이 세포의 정상적인 증식을 위해 꼭 필요한(‘prrmissive') 역할을 할 수 있다는 점을 시사한다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.747-754
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• 2005

Nutritional regulation of gene expression associated with growth and feeding behavior in avian species can become an important technique to improve poultry production according to the supply of nutrients in the diet. Insulin-like growth factor-I (IGF-I) found in chickens has been characterized to be a 70 amino acid polypeptide and plays an important role in growth and metabolism. Although it is been well known that IGF-I is highly associated with embryonic development and post-hatching growth, changes in the distribution of IGF-I gene expression throughout early- to late-embryogenesis have not been studied so far. We revealed that the developmental pattern of IGF-I gene expression during embryogenesis differed among various tissues. No bands of IGF-I mRNA were detected in embryonic liver at 7 days of incubation, and thereafter the amount of hepatic IGF-I mRNA was increased from 14 to 20 days of incubation. In eyes, a peak in IGF-I mRNA levels occurred at mid-embryogenesis, but by contrast, IGF-I mRNA was barely detectable in the heart throughout all incubation periods. In the muscle, no significant difference in IGF-I gene expression was observed during different stages of embryogenesis. After hatching, hepatic IGF-I gene expression as well as plasma IGF-I concentration increases rapidly with age, reaches a peak before sexual maturity, and then declines. The IGF-I gene expression is very sensitive to changes in nutritional conditions. Food-restriction and fasting decreased hepatic IGF-I gene expression and refeeding restored IGF-I gene expression to the level of fed chickens. Dietary protein is also a very strong factor in changing hepatic IGF-I gene expression. Refeeding with dietary protein alone successfully restored hepatic IGF-I gene expression of fasted chickens to the level of fed controls. In most circumstances, IGF-I makes a complex with specific high-affinity IGF-binding proteins (IGFBPs). So far, four different IGFBPs have been identified in avian species and the major IGFBP in chicken plasma has been reported to be IGFBP-2. We studied the relationship between nutritional status and IGFBP-2 gene expression in various tissues of young chickens. In the liver of fed chickens, almost no IGFBP-2 mRNA was detected. However, fasting markedly increased hepatic IGFBP-2 gene expression, and the level was reduced after refeeding. In the gizzard of well-fed young chickens, IGFBP-2 gene expression was detected and fasting significantly elevated gizzard IGFBP-2 mRNA levels to about double that of fed controls. After refeeding, gizzard IGFBP-2 gene expression decreased similar to hepatic IGFBP-2 gene expression. In the brain, IGFBP-2 mRNA was observed in fed chickens and had significantly decreased by fasting. In the kidney, IGFBP-2 gene expression was observed but not influenced by fasting and refeeding. Recently, we have demonstrated in vivo that gizzard and hepatic IGFBP-2 gene expression in fasted chickens was rapidly reduced by intravenous administration of insulin, as indicated that in young chickens the reduction in gizzard and hepatic IGFBP-2 gene expression in vivo stimulated by malnutrition may be, in part, regulated by means of the increase in plasma insulin concentration via an insulin-response element. The influence of dietary protein source (isolated soybean protein vs. casein) and the supplementation of essential amino acids on gizzard IGFBP-2 gene expression was examined. In both soybean protein and casein diet groups, the deficiency of essential amino acids stimulated chickens to increase gizzard IGFBP-2 gene expression. Although amino acid supplementation of a soybean protein diet significantly decreased gizzard IGFBP-2 mRNA levels, a similar reduction was not observed in chickens fed a casein diet supplemented with amino acids. This overview of nutritional regulation of IGF-I and IGFBP-2 gene expression in young chickens would serve for the establishment of the supply of nutrients to diets to improve poultry production.