• Korean Journal of Veterinary Research
• /
• v.43 no.4
• /
• pp.563-571
• /
• 2003

Dysfunction of mesangial cells has been contributed to the onset of diabetic nephropathy. Insulin like growth factors (IGFs) are also implicated in the pathogenesis of diabetic nephropathy. However, it is not yet known about the effect of high glucose on IGF-I and IGF-II secretion in the mesangial cells. Furthermore, the relationship between cAMP and high glucose on the secretion of IGFs was not elucidated. Thus, we examined the mechanisms by which high glucose regulates secretion of IGFs in mesangial cells. Glucose increased IGF-I secretion in a time- (>8 hr) and dose- (>15 mM) dependent manner (p<0.05). Stimulatory effect of high glucose on IGF-I secretion is predominantly observed in 25 mM glucose (high glucose), while 25 mM glucose did not affect cell viability and lactate dehydrogenase release. High glucose also increased IGF-II secretion. The increase of IGF-I and IGF-II secretion is not mediated by osmotic effect, since mannitol and L-glucose did not affect IGF-I and IGF-II secretion. 8-Br-cAMP mimicked high glucose-induced secretion of IGF-I and IGF-II. High glucose-induced stimulation of IGF-I and IGF-II secretion was blocked not by pertussis toxin but by SQ 22536 (adenylate cyclase inhibitor). Rp-cAMP (cAMP antagonist), and myristoylated protein kinase A (PKA) inhibitor amide 14-22 (protein kinase A inhibitor). These results suggest that cAMP/PKA pathways independent of Gi protein may mediate high glucose-induced increase of IGF-I and IGF-II secretion in mesangial cells. Indeed, glucose (>15 mM glucose) increased cAMP formation. In conclusion, high glucose stimulates IGF-I and IGF-II secretion via cAMP/PKA pathway in mesangial cells.

• Clinical and Experimental Pediatrics
• /
• v.61 no.7
• /
• pp.226-230
• /
• 2018

Purpose: This pilot study assessed changes in the growth plate and growth rates in children during a 6-month period. Methods: The study included 31 healthy children (17 boys, 14 girls) under evaluation for growth retardation. Height, weight, bone age, insulin like growth factor-1 (IGF-1), and insulin like growth factor binding protein 3 (IGF-BP3) were measured at baseline and after 6 months. In addition, the diameter, thickness, and volume of the femoral and tibial growth plates were measured using magnetic resonance imaging. Results: The mean bone age in boys and girls was 11.7 and 10.7 years, respectively. In boys, height (z score) (-0.2 vs. 0.0), weight (z score) (0.8 vs. 1.1), body mass index (BMI) (z score) (1.27 vs. 1.5), IGF-1 (ng/mL) (343.6 vs. 501.8), and IGF-BP3 (ng/mL) (5,088.5 vs. 5,620.0) were significantly higher after 6 months. In girls, height (z score) (-1.0 vs. -0.7), weight (z score) (-0.5 vs. 0.1), BMI (z score) (-0.02 vs. 0.3), IGF-1 (ng/mL) (329.3 vs. 524.6), and IGF-BP3 (ng/mL) (4,644.4 vs. 5,593.6) were also significantly higher after 6 months. In both sexes, the mean diameter and volume of the femoral and tibial growth plates were significantly increased 6 months later. Conclusion: No significant correlation was found between changes in the growth plate and clinical parameters in children with growth retardation in this study, other than correlations of change in femoral diameter with weight and BMI. A larger, long-term study is needed to precisely evaluate the correlation between change in the growth plate and growth.

• Clinical and Experimental Pediatrics
• /
• v.52 no.3
• /
• pp.356-363
• /
• 2009

Purpose : A polymorphism in the IGF-I gene promoter region is known to be associated with serum IGF-I levels, birth weight, and body length, suggesting that IGF-I gene polymorphism might influence postnatal growth. The present study aimed to investigate the role of this polymorphic cytosine-adenine (CA) repeat of the IGF-I gene in children with idiopathic short stature. Methods : The study involved 131 children (72 boys and 59 girls) diagnosed with idiopathic short stature, aged 715 years. Genomic DNA was extracted from anticoagulated peripheral whole blood. The primers were designed to cover the promoter region containing the polymorphic CA repeat. Data were analyzed using GeneMapper software. The correlations between age and serum IGF-I levels were analyzed using Spearmans correlation coefficient. Results : The CA repeat sequences ranged from 15 to 22, with 19 CA repeats the most common with an allele frequency of 40.6%. Homozygous for 19 CA repeat was 13.0%, heterozygous for 19 CA repeat was 56.5%, and 19 CA non-carrier was 30.5%. The three different genotype groups showed no significant differences in height, body weight and body mass index, and serum IGF-I levels. The serum IGF-I level and age according to the IGF-I genotypes were significantly correlated in the entire group, 19 CA repeat carrier group, and the non-carrier group. The three groups also showed no significant differences in the first year responsiveness to GH treatment. Conclusion : There were no significant different correlations between 19 CA repeat polymorphism and serum IGF-I levels according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not functional in children with idiopathic short stature.

• 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.

• Biomolecules & Therapeutics
• /
• v.22 no.6
• /
• pp.532-539
• /
• 2014

Peripheral neuropathy induced by human immunodeficiency virus (HIV) infection and antiretroviral therapy is not only difficult to distinguish in clinical practice, but also difficult to relieve the pain symptoms by analgesics because of the severity of the disease at the later stage. Hence, to explore the mechanisms of HIV-related neuropathy and find new therapeutic options are particularly important for relieving neuropathic pain symptoms of the patients. In the present study, primary cultured embryonic rat dorsal root ganglion (DRG) neurons were used to determine the neurotoxic effects of HIV-gp120 protein and/or antiretroviral drug dideoxycytidine (ddC) and the therapeutic actions of insulin-like growth factor-1 (IGF-1) on gp120- or ddC-induced neurotoxicity. DRG neurons were exposed to gp120 (500 pmol/L), ddC ($50{\mu}mol/L$), gp120 (500 pmol/L) plus ddC ($50{\mu}mol/L$), gp120 (500 pmol/L) plus IGF-1 (20 nmol/L), ddC ($50{\mu}mol/L$) plus IGF-1 (20 nmol/L), gp120 (500 pmol/L) plus ddC ($50{\mu}mol/L$) plus IGF-1 (20 nmol/L), respectively, for 72 hours. The results showed that gp120 and/or ddC caused neurotoxicity of primary cultured DRG neurons. Interestingly, the severity of neurotoxicity induced by gp120 and ddC was different in different subpopulation of DRG neurons. gp120 mainly affected large diameter DRG neurons (> $25{\mu}m$), whereas ddC mainly affected small diameter DRG neurons (${\leq}25{\mu}m$). IGF-1 could reverse the neurotoxicity induced by gp120 and/or ddC on small, but not large, DRG neurons. These data provide new insights in elucidating the pathogenesis of HIV infection- or antiretroviral therapy-related peripheral neuropathy and facilitating the development of novel treatment strategies.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.5
• /
• pp.474-481
• /
• 2019

This study evaluated the chronic effects of $NO_3-N$ on juvenile blackhead seabream Acanthopagrus schlegelii. The experiment used six identically configured recirculating aquaculture systems (435 L), with three tanks (70 L) each. The $NO_3-N$ concentrations studied were 0 (control), 62.5, 125, 250, 500, and 1,000 mg/L $NO_3-N/L$. Thirty juvenile blackhead seabream ($18.8{\pm}2.2g$) were stocked in each tank. Growth and hematological changes were evaluated after 120 days. At the end of the experiment, the growth, survival, and cortisol levels indicated that blackhead seabream were healthy in 500 mg $NO_3-N/L$. However, insulin-like growth factor I (IGF-1) and the IGF-1 receptor were significantly lower at 250, 500, and 1,000 mg $NO_3-N/L$ than in controls (62.5 and 125 mg $NO_3-N/L$). Juveniles were likely affected at a much lower $NO_3-N$ concentration than 250 mg/L $NO_3-N/L$ in terms of IGF-1 and the IGF-1 receptor. Therefore, for the sake of long-term fish welfare, the $NO_3-N$ should be maintained at lower than 250 mg/L for blackhead seabream in recirculating aquaculture systems.

• Nutritional Sciences
• /
• v.3 no.2
• /
• pp.57-65
• /
• 2000

Partial enteral nutrition (PEN) supplemented with insulin-like growth factor-I (IGF-I) to neonatal piglets receiving parenteral nutrition increases lactase-phlorizin hydrolase (LPH) activity, but not LPH mRNA. The goal of the current study was to investigate the mechanism by which IGF-I up-regulates LPH activity. We hypothesized that IGF-I regulates LPH synthesis post-transcriptionally. Methods: Newborn piglets (n=15) received 100% parenteral nutrition (TPN), 80% parenteral nutrition + 20% PEN (PEN), or PEN + IGF-I (1.0mg/kg/d). On day 7, two stable isotopes of leucine, [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine were intravenously administered to measure mucosal protein and brush LPH (BB LPH) synthesis. Results: Weight gain, nutrient intake and jejunal weight and length were similar among the treatment groups. PEN increased mucosal weight, villus width and cross-sectional area, LPH activity, mRNA expression and the abundance of proLPHh compared to 100% TPN (p<0.05). IGF-I further increased mucosal weight, LPH activity and LPH activity per unit BB LPH ~2-fold over PEN alone (p<0.05), but did not affect LPH mRNA or the abundance of proLPHh or mature LPH. Isotopic enrichment of [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine in plasma, mucosal protein and LPH precursors, and the fractional and absolute synthesis rates of mucosal protein and LPH were similar among the treatment groups. Total mucosal protein synthesis was increased 60% (p<0.05) and LPH synthesis tended (p=0.14) to be greater in the IGF-I treated animals compared to the other two groups. Conclusions: The primary mechanism by which IGF-I up-regulates LPH may be post-translational, either via reducing LPH turnover, or by specifically altering LPH activity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.6
• /
• pp.541-545
• /
• 2000

This study examines the effects of alginic acid, a source of dietary fiber, in a glucose-derived media. In particular, we examined how the presence or absence of alginic acid affected the differentiation and triglyceride densities of 3T3-L1 cells. We established that the addition of insulin-like growth factor-I (IGE-I) to 3T3-L1 cells results in acceleration of differentiation. We sought to determine the role of alginic acid in the production of fat by adding alginic acid to 3T3-L1 cells and examining its ability to limit or potentiate this stimulatory effects of IGE-I and IGF binding proteins. We have determined that alginic acid restricts 3T3-L1 cell differentiation and the creation of triglycerides, effectively attenuating 3T3-L1 cell metablolism and growth.

• Clinical and Experimental Pediatrics
• /
• v.49 no.12
• /
• pp.1340-1347
• /
• 2006

Purpose : The aim of the present study was to investigate the role of polymorphic cytosine adenine (CA) repeat of the IGF-I gene in the age-related alterations of serum IGF-I levels in healthy children. Methods : Two hundred and forty three normal healthy children (136 boys; 107 girls) aged between 7 and 15 years were enrolled in the present study. The primers were designed to cover the promoter regions containing the polymorphic CA repeat. Data were analyzed using GeneMapper software, version 3.7. All analyses were performed using MEDCALC software packages. Results: Deletion of 2 bp (G, A) following 3' of CA repeat were observed in all Korean children. The CA repeat sequences ranged from 17 to 23, and 19 CA repeat were the most common with an alleles frequency of 39.3 percent. Considering genotypes, 63.8 percent of subjects were homozygote or heterozygote for 19 CA repeat (192 bp allele), suggesting that this is wild type allele from which all other alleles originated in Korean children. Homozygote for 19 CA repeat were 14.7 percent, heterozygote for 19 CA repeat was 49.1 percent and 19 CA noncarriers totalled 36.2 percent. In 19 CA repeat noncarriers, the mean height, weight and serum IGF-I level were lower compared with those of 19 CA homozygous carriers, but statistically not significant. Correlations between serum IGF-I level and age according to the IGF-I genotypes revealed statistically significant relationships in the all groups, in the 19 CA repeat carrier group and, even in the noncarrier group. Conclusions : There were no significant differences of the mean height, weight and serum IGF-I levels among three different genotype groups. Also, there were no significantly different correlations between 19 CA repeat polymorphisms and serum IGF-I levels, according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not associated with circulating IGF-I levels in healthy children.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.1
• /
• pp.17-20
• /
• 2001

The effect of chicken IGF-I on protein synthesis of chicken embryo myoblasts cultured in serum-free medium was examined. When myoblasts were expanded to approximate 20-30% of well, the medium was changed to the serum-free medium including 0, 2, 20, 200 or 2000 ng/ml of recombinant chicken IGF-I. The culture medium including 10% fetal calf serum (FCS) was used as positive control. After 1 day of incubation, protein synthesis was measured by the incorporation of [$^3H$]-L-leucine. Thereafter cells were continued to incubate for further 18 hours, and the radioactivity in the protein was measured as an index of protein synthesis. The values for protein synthesis cultured in the serum-free medium without chicken IGF-I or with 2000 ng/ml of chicken IGF-I were the lowest. Protein synthesis was elevated with increasing chicken IGF-I concentration from 0 to 20 ng/ml. The values for protein synthesis in the 20 ng/ml and 200 ng/ml IGF-I groups were about half of that of the FCS group. The present study revealed that the potency of chicken IGF-I at the levels of 20 to 200 ng/ml to stimulate myoblast protein synthesis was about half of that of 10% FCS.