• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.89-90
• /
• 2001

Insulin-like growth factor-I(IGF-I)은 70개의 아미노산으로 이루어진 polypeptides로서 pronsulin과 구조적으로 유사하다(Froesch and Zapf, 1985). IGF-I은 척추동물에서 성장호르몬의 매개로 생성되어 동물의 성장 발달에 중요한 역할을 하고 있으며 세포의 성장, 분화, 대사에 다양한 효과를 보여주고 있다(Cohich and Clemmons, 1993; Baxter, 1993). 또한 체성장을 가속화시키고 in vivo에서는 단백질의 합성을 촉진시킨다(Rotwein et al., 1987). (중략)

• Korean Journal of Veterinary Research
• /
• v.40 no.3
• /
• pp.489-496
• /
• 2000

This study was conducted to investigate the effects of streptozotocin-induced (STZ) diabetes on insulin-like growth factor-I (IGF-I), insulin-like growth factor binding proteins (IGFBPs), and IGF-I carrier proteins in serum, liver, and kidney. The levels of total and free IGF-I were measured by radioimmunoassay (RIA). The patterns of IGFBPs were determined by western ligand blotting (WLB) analysis. The profiles of IGF-I carrier proteins in serum were determined by column chromatography. The levels of total and free IGF-I in serum were lower in STZ-induced diabetic rat than normal rat (p<0.01). Similarly, the levels of total IGF-I in liver was lowered in STZ-induced diabetic rats. On the other hand, the levels of total IGF-I in kidney were increased in STZ-induced diabetic rats compared with normal rats (p<0.01). In serum and liver from STZ-induced diabetic rats, the amount of IGFBP-3 was decreased and the amount of IGFBP-2 was increased compared with normal rats. There was a not difference in amount of IGFBP-4 in serum between STZ-induced diabetic rats and normal rats. The serums of normal rats have higher 150kDa carrier proteins than in STZ-induced diabetic rats, whereas, most of 50kDa carrier proteins were found in STZ-induced diabetic rats. These results demonstrate that in STZ-induced diabetic rats, IGF-I/IGFBPs system that included functional bioactivity was changed in serum as well as tissues, and these changes may play an important role in pathogenesis of diabetes.

• Food Science of Animal Resources
• /
• v.24 no.2
• /
• pp.171-175
• /
• 2004

Insulin-like growth factor-I (IGF-I) rich fraction, which was obtained molecules ranged between 30 kDa and 1 kDa, was fractionated by ultrafiltration from bovine colostral whey with 30 kDa and 1 kDa membrane. IGF-I included in fractionated IGF-I rich fraction was confirmed by SDS-PAGE and western blotting and then the quantity of IGF-I was measured by ELISA. IGF-I concentration in IGF-I rich fraction was 10ng/mg protein. Effect of IGF-I rich fraction on in vitro proliferation of several cells was tested. IEC-6 cell proliferation rate was increased 60％. 53％, 30％, and 20％ at l0ng, 1ng, 0.1ng and IGF-I of IGF-I, respectively, compared to control group which was not supplemented by IGF-I rich fraction. IGF-I rich fraction stimulated in vitro proliferation of IEC-6 cell in a dose dependent manner by increasing cell number. Detroit 551 cell proliferation was enhanced 56％ and 26％ at 10ng and 1ng level of IGF-I, respectively, compared to control group. EL-4 cell and L6 cell proliferation was increased 53％ and 46％ at 10ng of IGF-I, respectively, compared to control group.

• Journal of Veterinary Clinics
• /
• v.20 no.3
• /
• pp.263-273
• /
• 2003

This study was carried out to investigate the effects of the Korean Safflower (Carthamus inctorius L) seed powder on serum level of hormones and trabecula area during the recovery from osteoporosis induced ovariectomized rats. Four month-old rats were ovariectomized (OVX), remained untreated for 8 weeks, and were subsequently administered safflower seed (0.03 g/kg) every other day 30 for days. We examined the effects of treated safflower seed every 10 days on ovariectomy-related changes in Insulin-like Growth Factors, Insulin-like Growth Factor binding protein-3 (IGFBP-3), Estrogen, Bone-specific alkaline phosphotase, Calcium, and Phospotase in the serum, and also histomorphology of the proximal fibula metaphysis and femur/body weight rate. Ten and 20 days after safflower seed treatment in OVX rats, serum levels of IGF-I, -II and IGFBP-3 were not different from the Sham and OVX groups. In 30 days, serum levels of IGF-I,-II and IGFBP-3 were higher after safflower seed treatment in OVX rats as compared to the other two groups (p<0.05). Bone alkaline phosphatase levels were increased through safflower seed treatment in OVX rats compared to the other two groups in 30 days. There were no differences between OVX and safflower seed treated OVX rats in serum levels of estrogen and femur/body weight rate, but estrogen levels for the sham group were higher than for the other two groups. The safflower seed is increased to serum levels of IGFs, IGFBP-3 and BALP of osteoporosis induced by ovariectomized rats. Thus, we conclude that the safflower seed is a possible role for improvement of osteoporosis induced-ovariectomized rats.

• Journal of Life Science
• /
• v.27 no.8
• /
• pp.879-887
• /
• 2017

It is well established that brain-derived neurotrophic factor (BDNF) is expressed not only in the brain but also in skeletal muscle, and is required for normal neuromuscular system function. Histone deacetylases (HDACs) and insulin-like growth factor-I (IGF-I) are potent regulators of skeletal muscle myogenesis and muscle gene expression, but the mechanisms of HDAC and IGF-I in skeletal muscle-derived BDNF expression have not been examined. In this study, we examined the effect of IGF-I and suberoylanilide hydroxamic acid (SAHA), a pan-HDAC inhibitor, on BDNF induction. Proliferating or differentiating C2C12 skeletal muscle cells were treated with increasing concentrations (0-50 ng/ml) of IGF-I in the absence or presence of $5{\mu}M$ SAHA for various time periods (3-24 hr). Treatment of C2C12 cells with IGF-I resulted in a dose- and time-dependent decrease in BDNF mRNA expression. However, inhibition of HDAC led to a significant increase in the expression of BDNF mRNA levels. In addition, immunocytochemistry revealed high BDNF protein levels in undifferentiated C2C12 skeletal muscle cells, whether untreated, IGF-I-treated, or exposed to SAHA. These results represent the first evidence that IGF-I can suppress the mRNA and protein expression of BDNF; conversely, SAHA attenuates the effects of IGF-I. Consequently, SAHA upregulates BDNF expression in C2C12 skeletal muscle cells.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.3
• /
• pp.406-409
• /
• 2002

The effect of refeeding with various single essential amino acids on the recovery of plasma insulin-like growth factor-I (IGF-I) concentration in fasted young chickens was examined. Young chickens (29 days of age) were divided into 15 experimental groups. Chickens in one group were fed on the commercial diet ad libitum for 4 days. The remaining 56 chickens in 14 experimental groups were fasted. After 2 days of fasting, 52 chicks in 13 fasted groups were refed with one of the following experimental diets for 2 days. Eleven experimental diets were protein-free diets supplemented with one of 11 essential amino acids (Arg, Gly, His, Ileu, Leu, Met, Phe, Lys, Thr, Trp, Val). The remaining 2 experimental diets were a protein-free diet containing 11 essential amino acids and a protein-free diet not supplemented with amino acids. Birds in the remaining fasted group continued to be fasted for 2 days. Fasting for 2 days markedly reduced plasma IGF-I concentration. When fasted chickens were refed the protein-free diet containing either Gly alone or all essential amino acids, plasma IGF-I concentration was recovered to the level similar to that of fed chickens. Protein-free diet alone, however, failed to restore the reduced IGF-I concentration in plasma. Body weight loss modulated by feeding with protein-free diets supplemented with various single essential amino acids was associated with changes in plasma IGF-I concentrations. We concluded that body weight loss by feeding with a protein-free diet was lower than that of fasted chickens and that body weight loss associated with the decrease in plasma IGF-I concentration was modulated by feeding with protein-free diets containing various single essential amino acids.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.4
• /
• pp.471-482
• /
• 2009

Nutrient availability may control muscle growth directly and indirectly through its influence on regulatory factors. We analyzed the effects of nutrient availability on the breast muscle insulin-like growth factor system. Real time RT-PCR was used to quantify the level of transcription in breast muscle from Langshan (LS) layer and Arbor Acres (AA) broiler chickens subjected to different feeding regimens during embryonic and postnatal development. The AA chickens were fed AA diet (AA, control group) while the LS chickens were either fed LS diet (LL) or AA diet (LA). According to our results, insulin-like growth factor (IGF)-II (embryonic day 16 (E16) - postnatal day 42 (P42)), IGF-I receptor (IGF-IR, E18-P42), and IGF binding protein (IGFBP)-2 (E18-P42), -5 (E16-P14), -7 (E12-P0), and -3 (E12-P0) were positively correlated with IGF-I, while IGFBP-3 (P0-P28) was negatively correlated with IGF-I. In comparison, IGF-IR (E18-P42), IGFBP-2 (E18-P42), IGFBP-5 (E14-P0), and IGFBP-3 (E16-P0) were positively correlated with IGF-II, while IGF-IR (E10-E16) and IGFBP-3 (P0-P28) were negatively correlated with IGF-II. Moreover, IGFBP-2 (E16-P42), -7 (E10-E16), and -3 (E10-E16) were positively correlated with IGF-IR, while IGFBP-3 (P0-P28) was negatively correlated with IGF-IR. Finally, IGFBP-7 (E12-P0) was positively correlated with IGFBP-3, while IGFBP-2 (P0-P28) and -7 (P0-P42) were negatively correlated with IGFBP-3. Overall, the AA chickens exhibited higher levels of IGF-I, IGF-IR, and IGFBP-2 mRNA expression than the LL chickens, while the opposite was true for IGFBP-7. No strain differences in IGF-I, IGF-IR, and IGFBP-7 mRNA expression were detected between LA and AA chickens; however, a strain difference was observed for IGFBP-2. LA chickens exhibited higher levels of IGFBP-2 than LL chickens, while the opposite was true for IGFBP-7. Our data show the first evidence that certain genes may be correlated during specific developmental periods and that strain differences in the expression of those genes in LS and AA chickens are due to differential responses to the same diet.

• Biomedical Science Letters
• /
• v.12 no.3
• /
• pp.217-224
• /
• 2006

It has been reported that the dysfunctions of podocytes are associated with the development of diabetic nephropathy. In addition, insulin-like growth factors (IGFs) are associated with the development of diabetic nephropathy. However, it is not yet known about the effect of high glucose on IGF-I, -II secretion, and IGF binding proteins (IGFBPs) expression in the podocytes. Thus, this study was conducted to examine the effect of high glucose on IGF system and its involvement of protein kinase C (PKC) and mitogen activated protein kinases (MAPKs) in podocytes. In this study, high glucose (25 mM) increased IGF-I and IGF-II secretion (P<0.05), which was blocked by SB 203580 (a p38 MAPK inhibitor) but not by PD 98059 (a p44/42 MAPK inhibitor). In addition, high glucose-induced stimulation of IGFs was blocked by bisindolylmaleimide I and staurosporine (protein kinase C inhibitors). High glucose also increased IGFBP-l expression, which was blocked by bisindolylmaleimide I and SB 203580. In conclusion, high glucose alters IGFs secretion and IGFBP expression via PKC and p38 MAPK pathways in podocytes.

• Journal of Life Science
• /
• v.17 no.9 s.89
• /
• pp.1224-1231
• /
• 2007

Insulin-like growth factor-I (IGF-I) and IGF-II have structure like insulin. In contrast to insulin, however, the bioavaility of IGFs is modulated by the IGF-binding protein (IGFBPs). Each of IGFBPs was different with molecular masses, biological characteristics, and immunological properties.. Human fibroblasts secrete IGFBPs that can modify IGF-I action. In diabetes mellitus, the most study of IGF systems have been investigated in insulin-dependent diabetes mellitus, non-insulin-dependent diabetes mellitus, and streptozotocin-in-duced animals in vivo. Recently, a little research regarding the IGFs system has been proposed in por-tion of cell in vitro. In this study, effects of low or high glucose condition on IGFBP-5 in GM10 was investigated. By western blotting analysis, IGFBP-5 level decreased in cells cultured at high glucose, but IGFBP-5 level of mRNA didn't change. IGFBP-5 protease that cleaves IGFBP-5 in conditioned me-dium had was inhibited by EDTA and heparin, like serine protease and metalloprotease. Furthermore, the protease activity was increased in high glucose cultivated condition. In results of gelatin zymog-raphy, molecular weight of proteolytic metalloenzymes was indentified 69-kDa and protease activity was increased in time-dependent manner. Although the mechanism has yet to be determined, IGFBP-5 proteolysis in GM10 cells cultured with high glucose may increase effects of IGFs to decrease the glu-cose level through dissociation of IGFs from IGFBPs. Therefore, we suggest that IGF- I and IGFBPs could be potential models in study of pathophysiology such as diabetes mellitus.

• Development and Reproduction
• /
• v.20 no.3
• /
• pp.179-185
• /
• 2016

The insulin-like growth factor (IGF) pathway is a key signal transduction pathway involved in cell proliferation, migration, and apoptosis. In dairy cows, IGF family proteins and binding receptors, including their intracellular binding partners, regulate mammary gland development. IGFs and IGF receptor interactions in mammary glands influence the early stages of mammogenesis, i.e., mammary ductal genesis until puberty. The IGF pathway includes three major components, IGFs (such as IGF-I, IGF-II, and insulin), their specific receptors, and their high-affinity binding partners (IGF binding proteins [IGFBPs]; i.e., IGFBP1-6), including specific proteases for each IGFBP. Additionally, IGFs and IGFBP interactions are critical for the bioactivities of various intracellular mechanisms, including cell proliferation, migration, and apoptosis. Notably, the interactions between IGFs and IGFBPs in the IGF pathway have been difficult to characterize during specific stages of bovine mammary gland development. In this review, we aim to describe the role of the interaction between IGFs and IGFBPs in overall mammary gland development in dairy cows.