• Childhood Kidney Diseases
• /
• v.3 no.2
• /
• pp.109-116
• /
• 1999

Purpose: Insulin-like growth factor(IGF)-I and -II are peptide growth factor whose activity is modulated by interaction with the family of six IGF-binding proteins(IGFBPs). IGF-I is detected in rat kidney and has metabolic and growth effects. This study was designed to examine temporal expression of IGFBPs in kidney during renal development and postischemic regeneration in rat. Method: The expression of IGFBPs in kidney during renal development from 15th day of gestation to adult life by using Northern blot analysis. We also examined the renal IGF-IGFBP axis in uremic rat by using Northern blot and immunohistochemistry. Results: The mRNA of IGFBP-1 and -3 were not or barely detected in fetal stages. However, the mRNA level of IGFBP-1 and -3 were increased gradually from day 7 after birth to adult. In contrast, the mRNA of IGFBP-2 and -5 were highly expressed in fetal stages and maintained almost same levels until day 7 (IGFBP-2) or day 30 (IGFBP-5) after birth, then their levels decreased markedly. The mRNA of IGFBP-4 were expressed moderately in fetal kidney and increased gradually after birth. Interestingly, the mRNA of IGFBP-1 and-4 were induced up to 3-5 fold during maximum regeneration period and were recovered to normal levels after acute ischemic injury. In contrast, the mRNA level of IGFBP-3 and-IGFBPrP-1 were decreased slightly at 1 day after ischemic injury, then recovered to normal level during maximum regeneration period. Conclusion: There were differential expressions of IGFBPs in kidney that can modulate IGF action on developing, differentiating, maintaining, and regenerating renal structure and function.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3191-3194
• /
• 2012

Objective: To investigate the association between the change of IGF-2 level in serum after transcatheter arterial chemoembolization (TACE) and hepatocellular carcinoma (HCC) progression, especially in relation to metastasis. Methods: IGF-2 in serum was measured by quantitative sandwich enzyme-linked immunosorbent assaybefore, 3 days and 4 weeks after TACE in 60 patients with HCC. The occurrence of HCC metastasis was also evaluated, 3 months after TACE. Results: (1) The average serum level of IGF-2 in the 60 patients with HCC was $136.5{\pm}87.3$ pg/ml; (2) A tendency for increase was observed with heterogenous uptake of octreotide and portal vein thrombosis. Metastatic foci were found in 37/38 patients in the group with IGF-2 increasing (97.0%), in contrast to 3/22 (13.6%) patients with IGF-2 decrease. Conclusion: The increase of IGF-2 level in serum appears to be associated with the occurrence of metastatic HCC after TACE and chemotherapy.

• Korean Journal of Veterinary Research
• /
• v.34 no.3
• /
• pp.457-463
• /
• 1994

Insulin-like growth factor-I(IGF-I) plays an important role in the regulation of mammalian and poultry growth. IGF-I has many actions in different tissues, which include metabolic, mitogenic, and differentiative actions. IGF-I induces insulin-like effects - such as increased cell glucose uptake and glycogen sysnthesis, however several physiological actions of IGF-I may not have been identified yet. In order to investigate the effect on growth in broiler chicken treated with exogenous insulin-like growth factor-I, 30 chickens were injected $50{\mu}g$ reconbinant human IGF- I (rhIGF- I ) per kg body weight as experimental group and 30 ckickens saline subcutanously as control, 3 times according to ages from 2 to 35 days. We established radioimmunoassay method by which we can measure chicken IGF- I (cIGF- I ) as in rhIGF- I assay. The results obtained were as follows; 1) The dilution curve showed in parallelism between rhIGF- I and cIGF- I in the Sep-pak $C_{18}$ cartridge plasma extracts. 2) The body weight of broiler chicken were significantly increased at 31 days($1,176.50{\pm}99.79g$) and 35 days($1,252.84{\pm}125.21g$) of age in treatment groups, compared with control group($1,011.88{\pm}40.22g,\;1,111.32{\pm}153.67g$). The liver and kidney weights on 35 days$(35.24{\pm}5.18g,\;11.05{\pm}1.47g)$ were significantly higher in rhIGF- I treated group than control group($30.95{\pm}4.04g,\;10.01{\pm}1.60g$) 3) The plasma concentration of IGF- l and total protein in rhIGF- I treated group were $58.17{\pm}1.69ng/ml$, $3.75{\pm}0.62g/dl$ respectively compared with control group $45.70{\pm}1.64ng/ml$, $2.32{\pm}0.53g/dl$. The results suggest that exogenous rhIGF- I increased total body weight, liver and kidney weights in broiler chicken, and it may increase IGF- I and total protein concentration in serum.

• Journal of Life Science
• /
• v.19 no.5
• /
• pp.593-597
• /
• 2009

The uterus plays a critical role in pregnancy and steroid hormones, and both estrogen (E2) and progesterone (P4) especially play important roles in the cross-talk between embryos and uterus to support the pregnancy. E2 stimulates uterine growth during early pregnancy to prepare for implantation of embryos. This cross-talk during the implantation period involves hormones (E2 and P4) and growth factors, including insulin-like growth factor-I (IGF-I). In the uterus of a pregnant pig, the action of E2 is mediated by estrogen receptor-${\beta}$ (ER-${\beta}$). The expression of ER-a was much higher in early pregnancy than in mid- and late- pregnancy, suggesting E2 secretion from embryos enhances transcription of ER-a during early pregnancy. In order to prove whether IGF-I is an E2 target gene, quantitative real-time PCR was performed on ovariectomized murine uterus with E2 and/or P4 treatment(s). Increased IGF-I mRNA expression was observed with E2 treatment, however, it was not significantly induced by P4 treatment, which clearly demonstrates that, in mice, E2 depends on the activation of uterine IGF-I gene expression. The expression of IGF-I in the uterus of pigs was much higher in early pregnancy than in mid- and late- pregnancy and these data exhibited the same expression pattern with the ER-${\beta}$ gene expression in the uterus. It suggests that a positive co-relationship between IGF-I and ER-${\beta}$ expression exists in the uterus, and that both gene expressions of IGF-I and ER-${\beta}$ are regulated by E2. It further suggests that uterine the IGF-I gene expression might be initiated by E2 secreted from embryos to increase ER-${\beta}$ gene expression, and that this increased ER-${\beta}$ further stimulates the expression of IGF-I in the uterus during early pregnancy.

• Journal of Marine Bioscience and Biotechnology
• /
• v.1 no.2
• /
• pp.119-125
• /
• 2006

To understand the comprehensive mechanisms of biological function for insulin-like growth factor-I (IGF-I) in vertebrates, we have investigated the cDNA sequence of this gene in the korean rockfish (Sebastes schlegeli). The mature form of korean rockfish IGF-I was found to be comprised of 67 amino acid residues, showing about a 7 kDa molecular weight. In this study, we used the polymerase chain reaction (PCR) to obtain a korean rockfish IGF-I (KR IGF-I) cDNA fragment, and methods of rapid amplification of cDNA ends (RACE) to obtain a full length of the KR IGF-I sequence. The KR IGF-I encoded for a predicted amino acid sequence showed identities of 93.6 %, 90.7 %, and 85.4 % in comparison with flounder, chinook salmon, and human IGF-I, respectively. To obtain recombinant biologically active polypeptides, korean rockfish B-C-A-D domains were amplified using the PCR, then the isolated cDNA was expressed in the E. coli BL21(DE3). The recombinant KR IGF-I protein biological function was measured by stimulation of [$^3H$] thymidine incorporation, suggesting the cDNA codes for the korean rockfish proIGF-I.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.5
• /
• pp.550-555
• /
• 2001

Insulin-like growth factor-I (IGF-I) is a mitogenic peptide with a molecular mass of 7 kDa. It is produced mainly in the liver and has important functions in the regulation of development and somatic growth. Moreover, Serum IGF-I concentration is regulated by the quantity and the nutritional quality of dietary protein. To determine the IGF-I level in Korean rockfish, Sabastes schlegeli, were fed four experiment diets that contained different protein quantities, namely $30\%,\;40\%,\;50\%\;and\;60\%$ for 70 days. Weight gain of the fish increased depending dietary protein quantity, Also, IGF-I concentrations increased according to dietary protein quantity, Feeding experiments were conducted to examine the effects of dietary protein sources on the serum IGF-I level in Korean rockfish, Fish meal (CO), soybean meal (SM), corn-gluten meal (CGM), meat meal (MM) and feather meal (FM) were used as variable protein sources of the formulated diet. IGF-I concentrations of the CO and MM groups ($277.7\pm23.2,\;291.5\pm41.2\;ng/mL$) were higher than those of the CGM and FM groups ($208.9\pm21.3,\;217.2\pm38.2\;ng/mL$). And IGFBP-3 levels by western blot analysis increased in good protein diets such as in the CO and MM groups. In conclusion, IGF-I may be a sensitive indicator the protein metabolism in fish as well as mammalian.

• Proceedings of the KSAR Conference
• /
• 2003.06a
• /
• pp.20-20
• /
• 2003

Phenotypic characteristics and genetic markers in livestock have been utilized for improvement of the economic traits including egg productivity. Korean Native Ogol Chicken (KNOC) has low egg productivity compared to White Leghorn. Therefore, in this study, serum IGF-I concentration and number of egg production were used as selection markers to improve egg productivity. KNOCs were divided into three groups showing high IGF-I concentration (IGF-I high), high egg production (EP high), and IGF-I/EP high groups. Blood was collected every 10 weeks, and serum concentrations of IGF-I, estradiol (E2), and progesterone (P4) were measured by radioimmunoassay. In comparison of three groups in each generation, the highest increment of egg production was detected in the IGF-I/EP high group from 20 weeks till 40 weeks, and the IGF-I high group also showed the significant increment of egg production after 50 weeks. Interestingly, there were the increase of egg production and decrease of periods in sexual maturity in the second and third generation selected by serum IGF-I concentration, while egg weight and body weight decreased during experimental period. In conclusion, the present study suggest the possibility of IGF-I as a selection marker to improve the egg productivity of KNOC.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.7
• /
• pp.903-912
• /
• 2012

In Erhualian and Yorkshire reciprocal cross $F_1$ pig populations, we examined the mRNA expression characteristic of liver-derived IGF-1, IGF-1R, IGF-2, IGF-2R and IGFBP-3 during the embryonic and postnatal developmental periods (E50, E70, E90, D1, D20, D70, D120 and D180). Our results demonstrated that the IGF-system genes mRNA levels exhibited an ontogenetic expression pattern, which was potentially associated with the porcine embryonic development, postnatal growth, organogenesis and even the initiation and acceleration of puberty. The expression pattern of IGF-system genes showed variation in the reciprocal cross ($F_1$ YE and EY pigs). This study also involved the expression features of imprinted genes IGF-2 and IGF-2R. The parent-of-origin effect of imprinted genes was reflected by their differential expression between the reciprocal crosses populations. The correlation analysis also indicated that the regulatory network and mechanisms involved in the IGF system were a complex issue that needs to be more fully explored. A better understanding of IGF system components and their interactive mechanisms will enable researchers to gain insights not only into animal organogenesis but also into somatic growth development and even reproduction.

• Journal of Embryo Transfer
• /
• v.13 no.3
• /
• pp.245-249
• /
• 1998

The purpose of this study was to evaluate the effects of growth factors such as epidermal growth factor (EGF) and insulin-like growth factor-1 (IGF-1) on maturation of bovine follicular oocytes in vitro. Oocytes were recovered from the ovaries of slaughtered Hanwoos. The oocytes were matured in TCM 199 at 39$^{\circ}C$, 5% $CO_2$ in air. Growth factors were added to maturation medium as follows: control (no serum), EGF (10ng/m1, 50ng/ml or 100ng/m1), IGF-1 (100ng/m1) and EGF (50ng/ml) + IGF-1 (100ng/m1). The oocytes were placed onto a slide and stained with aceto-orcein dye. Nuclear maturation was evaluated and classified as germinal vesicle breakdown (GVBD), metaphase-I (MI) or metaphase-ll(Mll). Maturation rates were 37.9% (control), 45.8% (EGF, 10ng/m1), 55.8% (EGF, 50ng/ml), 44.4% (EGF, 100ng/m1), 46.7% (IGF-1, 100ng/m1) and 67.0% (IGF-1+EGF). The highest group developed to Mll stage was IGF-1+EGF treatment group (p<0.05). Therefore, nuclear maturation of bovine oocytes were affected by both of growth factors, and it seems to have a mutual activity between them.

• Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.227-231
• /
• 1998

The teleosts represent ancient real-bony vertebrates in phylogeny and resemble major genetic patterns to higher vertebrates. In the present study, we have defined the single family of insulin-like growth factors (IGFs) from flounder (Paralichthys olivaceus), compared to the prototype of IGFs observed in the Agnathan hagfish. In flounder, IGFs are clearly diverged into two major types including type I and II, and they are structurally similar by displaying a multidomain structure consisting of five functional regions as previously found in other vertebrates. However, flIGF-I appears to be more basic (pI 8.03) than the flIGF-II (pI 5.34) in the fully processed form for the B to D domain region. The flIGF-I seems to contain an evolutionary conserved Asn-linked glycosylation in E domain, which is not found in flIGF­II. The most interesting feature is that flIGF-II appeared to be structurally close to hagfish IGF in secondary structures, particularly in Band D domains. This could tell us an idea on the molecular divergence of IGFs from the Agnatha to teleosts during the vertebrate phylogeny. It also support, in part, a notion regarding on how IGF-II is appeared as more embryonic during development. Nonetheless, the biologically active B to D domain region of flIGF-II shows significant sequence homology of $65.6\%$ to flIGF-Is and contains the evolutionary conserved insulin-family signature, as well as a reserved recognition site (Lys) in D domain, necessary to generate proteolytic cleavage for E-peptide. A significant structural difference was found in E domain in which flIGF-I possesses two potential alternative splicing donor site at $Val^{17,\;24}$ of E domain. Therefore, it seems so far that IGF-I sorely produces spliced variants due to the spliced E-peptide moiety while IGF-II appears to be maintained in a single type during evolution. IGF-II, however, may be also possible to transcribe unidentified variants, depending on the physiological conditions of tissues in vertebrates in vivo.