• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.113-118
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• 1999

The insulin-like growth factor (IGF) is found in all vertebrates and its type-II molecule is regarded as a fundamental embryonic growth factor during development. We have firstly identified, in this study, a cDNA clone corresponding to IGF-II (flIGF-II) from the adult brain of the teleost, Paralichthys olivaceus. We also examined the tissue expression of flIGF-II in several adult tissues by RT-PCR. The flIGF-II cDNA contained a complete ORF consisting of 215 amino acids and one stop codon. Its molecular characteristics appear to be similar to the previously identified IGF-II molecules, in which a common primary structure exhibiting B, C, A, D, and E domains is evidently observed. This cDNA clone seems to be cleaved at $Ala_{52}$ for the $NH_2$-end signal peptide and appears to produce a 98 amino acid-long E-peptide from the $Arg^{118}$. The functional B-D domain regions, therefore, include 65 amino acids and is able to encode a 7.4-kDa protein. The most prominent structural difference between IGF-I and IGF-II was that the D domain of IGF-II exhibits a two-codon-deleted pattern compared to the 8 amino acid-containing IGF-I. The insulin family signature in the A domain and six cysteins forming three disulfide bridges between the B and A domains were evolutionary-conserved from teleosts to mammalian IGF-II. Interestingly, the E-peptide region appears to provide a distinct hallmark between teleosts in amino acid composition. The flIGF-II shows 85.1% of sequence identity to salmon and trout, 90.6% to tilapia, and 98.4% to perch in amino acid level. In tissue expressions of IGF-II, it is very likely that flIGF-II has a significant expression in the adult brain. However, liver seems to be the main source for IGF-II production, and relatively low signals were observed in the adult muscle and kidney. Taken together, it would be concluded that the functional region for IGF-II mRNA is highly similar in phylogeny and is evolutionary, conserved as a mediator for the growth of vertebrates.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.2
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• pp.123-130
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• 2005

Many of the molecular and genotypic events taking place at the osteoblast cell level during bone-implant integration are still largely unknown. The objective of this study was to examine expression patterns of TGF-$\beta$ and IGF-I related genes during bone-implant integration. Titanium implants with machined surface were placed into 8 rabbit tibias. At 3rd, 7th, 14th, 28th day after implantation, the expression pattern of TGF-$\beta$ and IGF-I genes in bone with or without implant was examined using reverse transcriptase-polymerase chain reaction (RT-PCR). At the same time, histomorphometric analysis was evaluated, respectively. The bone-to-implant contacts (BIC) of experimental groups were 5.2%, 6.2%, 6.6%, 24.6% at 3rd, 7th, 14th, 28th day. This indicated that newly formed bone increased at the implant surface in bone marrow space after implantation. The expressions of TGF-$\beta$ and IGF-I were higher in implantation groups than untreated control groups during all experimental days. The increased expression of TGF-$\beta$ and IGF-I genes may be associated with the increased bone-to-implant contact. This result provided the evidence for existing biologic differences in tissue response after implantation and helped us to understand molecular biologic processes in tissue-implant integration.

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

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5315-5320
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• 2016

Purpose: Tumor cell growth and sensitivity to chemotherapy depend on many factors, among which insulin-like growth factors (IGFs) may play important roles. The aim of the present study was to evaluate the levels of insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in primary tumors and ascites as predictors of response to neoadjuvant chemotherapy in ovarian cancer (OC) patients. Materials and Methods: Tumor tissue samples and ascitic fluid were obtained from 59 patients with advanced OC. The levels of IGF-I, IGF-II, IGFBP-3, IGFBP-4 and PAPP-A were determined using ELISA kits. Taking into account the data on expression of these IGF-related proteins and outcome, logistic regression was performed to identify predictors of response to neoajuvant chemotherapy. Results: Human ovarian tumors expressed IGFs, IGFBP-3, IGFBP-4 and PAPP-A and these proteins were also present in ascites fluid and associated with its volume. IGFs and IGFBPs in ascites and soluble PAPP-A might play a key role in ovarian cancer progression. However, levels of proteins of the IGF system in tumors were not significant predictors of objective clinical response (oCR). Univariate analysis showed that the level of IGF-I in ascites was the only independent predictor for oCR. Conclusion: The level of IGF-I in ascites was shown to be an independent predictor of objective clinical response to chemotherapy for OC patients treated with neoadjuvant chemotherapy and debulking surgery.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.383-392
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• 2003

Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are important regulators on the development of maternal tissues during pregnancy. This study was performed to examine the relationship between maternal IGFs/IGFBPs system (i.e: IGF-I, II, their receptors, and IGFBPs) in pre- and post-partum rats. The liver and kidney are important organs for the synthesis of IGFs and IGFBPs in adults. The levels of materanal IGFs and IGFBPs in serum, liver, and kidney were examined at 14 and 21 days of gestation and at 3, 7, 11, and 14 days after birth. The expression of IGFs and their receptors mRNA was also examined in fetal and maternal rat liver, kidney. IGF-I concentrations in maternal serum and liver were decreased during pregnancy. However, IGF-I concentration in maternal kidney was increased, having maximal effect at 14 days of gestation. IGF-I concentrations were decreased in serum, liver, and kidney of postpartum rat, compared to control (p < 0.05). On the other hand, IGF-II concentrations in serum, liver, and kidney were increased during pregnancy (p<0.05) and gradually decreased to control level in postpartum period. The levels of IGFBP-3 and IGFBP-2 are expressed in serum, liver, and kidney. However, IGFBP-3 is mainly expressed in serum and liver, and IGFBP-2 in kidney. The levels of IGFBP-3 and IGFBP-2 in maternal serum were markedly decreased during pregnancy and gradually recovered to control level during postpartum period by western ligand blotting. However, there was no change of IGFBP-3 and IGFBP-2 levels by western immunoblotting. The levels of IGFBP-3 and IGFBP-2 in maternal liver and kidney also showed the same pattern of serum, although the main IGFBP is different. In normal rat serum, IGF-I 150 kDa and 50 kDa carrier proteins were detected. The level of IGF-I 150 kDa carrier proteins in pregnant rat was decreased compared to normal rat, but that of 50 kDa carrier proteins was increased. IGFBP-3 protease activity was identified in pregnant rat serum and maternal placenta, and it was inhibited by EDTA ($Ca^{2+}$ chelating agent) and aprotinin (serine proteinase inhibitor). Taken together, these results suggest that the changes of IGFs and IGFBPs in maternal rats are regulated by liver and kidney IGFs and their receptors mRNA during the pregnancy.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.213-220
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• 1999

The litter size has been the primary interest of economic traits in pig reproduction. It has been recently shown that insulin-like growth factor-Ⅰ(IGF-Ⅰ) plays roles in establishing pregnancy and in supporting fetal growth and development. But, the effect of serum IGF-Ⅰ on litter size has not been studied. Therefore, this study was conducted to relate serum IGF-Ⅰ concentration with porcine litter size and to investigate the possible connection with estrogen receptor(ER) as a candidate gene for the litter size. Sera during day 45 to 105 of pregnancy were collected from two groups showing high and low litter size and serum IGF-Ⅰ concentration was measured by radioimmunoassay (RIA). IGF-Ⅰ levels in both groups decreased gradually as pregnancy stage proceeded but were not significantly different. Secondly, DNA was extracted from blood and PCR-RFLP was utilized to analyze ER genotypes of pigs in each group, which produced three polymorphic patterns. Based on the ER genotypes analyzed, low litter size group showed higher IGF-Ⅰ concentration than high litter size group. Taken together, the results indicate that the serum IGF system was correlated with steroid system but not with the litter size in pigs. Thus, this study implies that porcine litter size could be determined locally at the ovary level.

• Korean Journal of Veterinary Research
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• v.46 no.2
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• pp.97-105
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• 2006

All-trans retinoic acid (AtRA) induces growth inhibition and apoptosis in a variety of tumer cells, including MCF-7 cells. Insulin-like growth factors (IGFs) system has been reported to be associated with the development of cancer. Although MCF-7 cell with AtRA is to be the major stimulus for the cell growth and apoptosis, the mechanism of insulin-like growth factor-I (IGF-I)/insulin-like growth factor binding protein-3 (IGFBP-3) system remains to be elucidated. Thus, this study was conducted to the effect of AtRA on the gene expression and level of IGF-I and IGFBP-3. In addition, we investigated the involvement of PKC-${\delta}$ on the IGF-I and IGFBP-3 secretion in MCF-7 cell. AtRA(${\geq}10^{-7}M$) decreased the IGF-1 secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cells. Especially, the treatment of AtRA at 72 hours caused a significant reduction in the IGF-I secretion and mRNA expressions but increment in IGFBP-3 secretion and mRNA expressions (p < 0.05). $10^{-7}M$ AtRA activated PKC-${\delta}$ that is one among PKC-$\iota$, ${\alpha}$, ${\lambda}$ and ${\delta}$ in MCF-7 cell. Rotllerin, a PKC-${\delta}$ inhibitor, blocked AtRA-induced inhibition of the IGF-I and mRNA expressions, and increase of lGFBP-3 and mRNA expressions in MCF-7 cell. Together, AtRA inhibited the IGF-I secretion and mRNA expressions, but increased IGFBP-3 secretion and mRNA expressions in MCF-7 cell. Furthermore, AtRA-induced alteration of IGF-I, IGFBP-3 secretion, and the gene expressions were mediated via PKC-${\delta}$ activity.

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

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.755-762
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• 2000

The aim of this investigation was to examine the effects of osteocalcin, bone-specific alkaline phophatase, estrogen, insulin-like growth factor-I (IGF-I), Ca, P and bone mineral density on osteoporosis induced by ovariectomy in rats. Female Sprague-Dawley 30 rats of three-forth's birth, weighing $215{\pm}10g$, were divided into two groups including the sham operation group(5 heads) and ovariectomy group(25 heads). They were fed normal diets for 2 weeks before the experimental operation and for 8 more weeks after operation. The level of osteocalcin, TALP, BALP, estrogen, bone mineral density and IGF-I were increased in experimental group, but a little increased in sham operation group at same period. The change of rates of osteocalcin, TALP, BALP, estrogen, bone mineral density and IGF-I were significantly higher in experimental group than sham operation group. $Ca^{2+}$ was not changed between two groups and P was significantly decreased in experimental group and Ca/P ratio was higher in experimental group than sham operation group. Body weights were increased in all two groups and growth rate per day was higher in experimental group than sham operation group. However, femur weight I body weight ratio was lower in experimental group than sham operation group.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1180-1185
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• 2009

Two experiments were carried out to study the effects of dietary energy level on nutrient digestion, nitrogen (N) utilization, growth performance, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-3 (IGFBP-3) in plasma, liver and longissimus dorsi muscle in growing-finishing pigs. In experiment 1 (Exp 1), 15 castrated male pigs (Duroc${\times}$Landrace${\times}$Large White) (Body weight, BW, 55.6${\pm}$1.8 kg) were divided into three groups and fed rations containing 13.33, 14.87 and 17.35 MJ digestible energy (DE)/kg as treatments I, II and III, respectively, using soybean oil as an energy source. The experiment lasted 8 days and faecal and urinary samples were collected during the last 3 days. The results showed that the digestibility of dry matter (DM), energy and N was increased from treatments I to III (p<0.01). N-retention and N-retention rate were not influenced by dietary DE level (p>0.05). In experiment 2 (Exp 2), 36 female pigs (Duroc${\times}$Landrace${\times}$Large White) (BW 41.5${\pm}$3.8 kg) were divided into three groups. The pigs were fed with the same three rations used in Exp 1 for 60 days. At the end of Exp 2, eight pigs were selected from each group for blood sampling and 4 pigs for slaughter trial. The results indicated that average daily feed intake (ADFI) and N-intake were significantly decreased (p<0.01), and DE intake (p<0.01) and average daily gain (ADG) (p<0.05) were increased. IGF-I and IGFBP-3 in plasma were increased (p<0.05). No significant differences in IGF-I and IGFBP-3 in liver and longissimus dorsi muscle were found between different treatments. It was concluded that higher dietary DE level improved nutrient digestibility, ADG and feed/gain ratio when soybean oil was used as an energy source in the ration of growing-finishing pigs. No significant differences were found in Nretention and IGF-I and IGFBP-3 in liver and longissimus dorsi muscle between different treatments.