Growth Factor Binding Protein Research Articles

Influence of insulin-like growth factor-binding proteins-2 and -3 in the pathogenesis of cystic ovarian disease in cattle

Ovarian cysts are one of the major causes of infertility in dairy cows. The development is associated with an endocrine imbalance in the hypothalamo–hypophyseal–gonadal axis in which endocrine factors participate in follicular growth and differentiation and in the secretion of ovarian hormones. Insulin-like growth factor family are essential local regulators of ovarian follicle development and functionality and actions are mediated by binding protein activity. The aim of the present study was to analyze the expression of IGFBP-2 and IGFBP-3 in developing follicles of normal estrous cycling animals and with spontaneous and induced cystic ovarian disease (COD) to determine IGF bioavailability. The mRNA of IGFBP-2 and IGFBP-3 in follicular walls was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. Protein expression was analyzed by immunohistochemistry. The results demonstrated reduced amounts of mRNA of both IGFBPs in the granulosa cells of ovarian follicles of animals with COD ( P < 0.05). The present study suggests that the IGF system or imbalances between IGFs and IGFBPs may be involved in COD of cattle.

Identification of Proteins Associated With let-7a in Gastric Carcinoma Cell Line SGC-7901 by Proteomics*

In order to elucidate the mechanisms of let-7a down-regulation in pathogenesy of gastric carcinoma,proteins associated with the function of let-7a were detected in high throughout screening.The cell line of SGC-7901 stablely overexpressing let-7a was successfully established by gene clone.Two-dimensional gel electrophoresis(2-DE) was used to separate the total proteins of SGC-7901/let-7a,SGC-7901/EV and SGC-7901,and PDQuest software was applied to analyze 2-DE images.Ten differential protein spots were identified by MALDI-TOF-MS,and they may be the proteins associated with let-7a function.The overexpressed proteins included antioxidant protein 2,insulin-like growth factor binding protein 2,protein disulfide isomerase A2,C-1-tetrahydrofolate synthase,cyclin-dependent kinase inhibitor1 and Rho-GTPase activating protein 4.The underexpressed proteins were consisted of S-phase kinase-associated protein 2,platelet membrane glycoprotein,fibronectin and Cks1 protein.Furthermore,the differential expression levels of the partial proteins(CDKN1,Spk2 and fibronectin) were confirmed by Western blot analysis.The 10 differentially expressed proteins could be divided into groups based on their functions: signal transduction,chaperone,transcription and translation,metabolism and cytoskeleton,which were involved in cell cycle,the transcription regulation,cell adherence,cellular metabolism and so on.The data suggest that these differential proteins may be associated with the function of let-7a in gastric carcinoma,and will be valuable for further to study the mechanisms of let-7a down-regulation in pathogenesy of gastric carcinoma.

Abstract 2122: Pleiotropic effects of TMEFF2 variants in tumorigenesis

Abstract TMEFF2, a gene with an expression profile limited to brain and prostate, contains several biologically important signatures. It encodes a transmembrane protein with a short cytoplasmic tail containing a potential G protein activating domain. The extracellular domain (ectodomain) is shed in an ADAM17/γ-secretase dependent fashion and consists of two follistatin (FS) modules and an epidermal growth factor-like (EGF) domain. A critical role for TMEFF2 in tumorigenesis is suggested by the fact that it is upregulated in a significant fraction of primary and metastatic prostate tumors; however, its role in this disease is still unknown. TMEFF2 has been suggested to function as a tumor suppressor, while the ectodomain has been shown to promote growth. The discrepancies likely arise from the complexity of TMEFF2 function. TMEFF2 could signal as a ligand, a membrane bound receptor and/or a binding protein for growth factors. In addition, several isoforms have been described that differ in their C-terminus and probably in their ability to signal and/or being modified. One of these isoforms constitutes a soluble form of the protein similar to the ectodomain. In the present study we investigate the possibility that different forms of TMEFF2 may have different roles in tumorigenesis. Our data indicate that constitutive or induced overexpression of TMEFF2 in HEK293T or prostate epithelial RWPE1 cells reduces cell proliferation by 20-30%, inhibits anchorage independent growth by 5 fold, sensitizes the cells to apoptotic stimuli by 2-3 fold and/or decreases cell migration and invasion by 2 fold, suggesting that TMEFF2 functions as a tumor suppressor. Conversely, overexpression of the ectodomain or an isoform of TMEFF2 that lacks the G protein activating domain (TMEFF2-ΔGA), results in a tumorigenic phenotype, i.e. increase in cell proliferation, anchorage-independent growth, cellular migration and/or invasion. In all, these results suggest functionally different roles for different TMEFF2 variants. The role of the G protein activating domain is currently being investigated. Importantly, we demonstrate that there is an association between the ability of these TMEFF2 variants to bind to SARDH and modulate sarcosine levels and their ability to suppress tumorigenesis. Using co-immunoprecipitation studies and sarcosine levels analysis, we show that the full length tumor suppressor form of TMEFF2 binds to SARDH and modulates sarcosine levels. In contrast, expression of TMEFF2-ΔGA or the ectodomain fails to modulate sarcosine levels or bind to SARDH and in both cases they exhibit tumor promoting phenotypes. This suggests that the function of TMEFF2 may rely, at least in part, on its ability to modulate sarcosine metabolism. Differential expression of these isoforms provides a potential mechanism for the pleiotropic effects of TMEFF2 during prostate cancer development and progression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2122. doi:10.1158/1538-7445.AM2011-2122

Abstract 139: MicroRNA-375 and microRNA-221: Potential noncoding RNAs associated with antiproliferative activity of benzyl isothiocyanate in pancreatic cancer

Abstract Large high-throughput studies in patients with pancreatic cancer revealed that oncogenic miR-221 is commonly upregulated microRNA whereas putative tumor suppressor miR-375 is generally down modulated when compared to adjacent benign pancreatic tissue or normal pancreas. In our laboratory, we observed that deregulated expression of miR-375 and miR-221 (as noted in pancreatic cancer patients) can be recapitulated in PDX1-Cre+; KRasG12D+ pancreatic cancer mouse model. Coherent data obtained from pancreatic cancer patient samples to preneoplastic lesions developed in preclinical mouse model tempted us to postulate that aberrant expression of these miRNAs (−375 and-221) might play significant role for the development of pancreatic cancer. Interestingly, ablation of miR-221 by ectopic expression of antagomir-221 in pancreatic ductal carcinoma cells can significantly exert antiproliferative effect with increased expression of p27kip1, a target of miR-221. To the other end, premiR-375 overexpression diminished cell proliferation with downmodulation of Insulin like growth factor binding protein 5 (IGFBP5) and Caveolin-1 (CAV-1 gene), which are of particular interest because of their potential link with pancreatic cancer cell growth and diagnosis. It is quite intriguing that the levels of both CAV-1 and IGFBP5 expression were elevated when miR-375 expression wanes in KRASG12D driven PanIN lesion in compound mutant mice. Previous studies in our laboratory demonstrate that benzyl isothiocyanate (BITC), a prototypical member of the isothiocyanate (ITC) family, inhibits proliferation of human pancreatic cancer cells by causing cell cycle arrest and inducing apoptosis. Interestingly, real time qRT-PCR analysis indicates that anticancer agent BITC can diminish oncogenic miR-221 expression and elevate the level of tumor suppressor miR-375 in pancreatic cancer cells. Besides, genetic manipulation studies revealed that enforced silencing of miR-221 or overexpression of miR-375 enhances the antiproliferative effect of BITC in pancreatic ductal carcinoma cells. Next we explored the efficacy of BITC to interfere with the development of mouse PanIN lesions. Results indicate that pancreata of BITC administered compound mutant mice exhibit reduced level of IGFBP5 protein. Histopathological analysis of the extent of PanINs as well as studies on the magnitude of expression of miR-221/miR-375 and other molecular mediators in these pancreata are in progress. Explicitly, our investigation might provide new insight into nonconventional microRNA replacement therapy against pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 139. doi:10.1158/1538-7445.AM2011-139

Growth Hormone Deficiency in Children and Adolescents with Cerebral Palsy: Relation to Gross Motor Function and Degree of Spasticity

Children with Cerebral Palsy (CP) often have poor linear growth during childhood with short final height. Thus, we aimed to assess serum growth hormone (GH), insulin like growth factor-1 (IGF-1) and insulin like growth factor binding protein-3 (IGFBP-3) levels among CP patients and their relation to each of gross motor function and degree of spasticity. Fifty CP children and adolescents were studied in comparison to 50 healthy age-, sex- and pubertal stage-matched children and adolescents. All subjects were subjected to clinical evaluation, Intelligence Quotient (IQ) assessment and measurement of serum GH, IGF-1 and IGFBP-3. All auxological and hormonal parameters were significantly lower among cases. Fifty two% of cases were GH-deficient and 62% had reduced IGF-land IGFBP-3 levels. Gross Motor Function Measure- 88 (GMFM-88) score correlated negatively with each of basal (r = -0.71, p = 0.02) and peak stimulated GH (r =-0.88, p = <0.001); IGF-1 (r = -0.64, p = 0.04) and IGFBP-3 (r = -0.69, p = 0.031). There were significant negative correlations between the degree of spasticity assessed by Modified Ashworth Scale and each of basal (r = -0.61, p = 0.032) and peak stimulated GH (r = -0.78, p = 0.01); IGF-1 (r = -0.65, p = 0.041) and IGFBP-3 (r = -0.62, p = 0.035). Growth Hormone Deficiency (GHD) is prevalent in children with CP and could be one of the causes of their short stature.

Evaluation of the insulin-like growth factors (IGF) IGF-I and IGF binding protein 3 in patients at high risk for breast cancer

Our data suggest that serum concentrations of insulin-like growth factor I and insulin-like growth factor binding protein 3 do not correlate with breast cancer development.

Advances in insulin like growth factor binding protein 1 in the prognosis of acute myocardial infarction.

Insulin-like growth factor (IGF) is closely associated with cardiovascular diseases. Low IGF-I level and high insulin-like growth factor binding protein-1 (IGFBP-1) level in serum can be used as a marker in predicting the long term morbidity and mortality of acute myocardial infarction (AMI). The article reviews the recent advances in IGFBP-1 in the prognosis of AMI.

Do insulin-like growth factor associated proteins qualify as a tumor marker? results of a prospective study in 163 cancer patients*

ObjectiveInsulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms.MethodsIn our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared.ResultsThe serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected.ConclusionThe IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.

Discovery of the serum biomarker proteins in severe preeclampsia by proteomic analysis

Preeclapsia (PE) is a severe disorder that occurs during pregnancy, leading to maternal and fetal morbidity and mortality. PE affects about 3-8% of all pregnancies. In this study, we conducted liquid chromatography- mass spectrometry/mass spectrometry (LC-MS/MS) to analyze serum samples depleted of the six most abundant proteins from normal and PE-affected pregnancies to profile serum proteins. A total of 237 proteins were confidently identified with <1% false discovery rate from the two groups of duplicate analysis. The expression levels of those identified proteins were compared semiquantitatively by spectral counting. To further validate the candidate proteins with a quantitative mass spectrometric method, selective reaction monitoring (SRM) and enzyme linked immune assay (ELISA) of serum samples collected from pregnant women with severe PE (n = 8) or normal pregnant women (n = 5) was conducted. α2- HS-glycoprotein (AHSG), retinol binding protein 4 (RBP4) and α-1-microglobulin/bikunin (AMBP) and Insulin like growth factor binding protein, acid labile subunit (IGFBP-ALS) were confirmed to be differentially expressed in PE using SRM (P<0.05). Among these proteins, AHSG was verified by ELISA and showed a statistically significant increase in PE samples when compared to controls.

IGFBP-3 Inhibits the Proliferation of Neural Progenitor Cells

Insulin like growth factor-1 (IGF-1) plays an important role in the proliferation and differentiation of neural progenitor cells. The effects of IGF-1 can be regulated by insulin like growth factor binding protein-3 (IGFBP-3) which can either inhibit or stimulate the proliferation of cells depending on the expression of proteases that can release IGF-1 from IGF1-IGFBP3 complex. Although IGF-1 is essential for the development of brain, both IGFBP-3 and IGF-1 are elevated in the brains of children younger than 6 months of age. Likewise, IGFBP-3 is also upregulated following cerebral ischemia and hypoxia. However, the role of IGFBP-3 in neurogenesis is not clear. Using an in vitro culture system of rat neural progenitor cells, we demonstrate that IGFBP-3 specifically regulates the IGF-1 mediated neural progenitor cell proliferation via down regulation of phospho-Akt, and cyclin D1. In addition, IGFBP-3 also decreased the content of nestin in the neural progenitor cells indicating its potential role in neurogenesis.

Screening of genetic parameters for soluble protein expression in Escherichia coli

Soluble expression of proteins in a relevant form for functional and structural investigations still often remains a challenge. Although many biochemical factors are known to affect solubility, a thorough investigation of yield-limiting factors is normally not feasible in high-throughput efforts. Here we present a screening strategy for expression of biomedically relevant proteins in Escherichia coli using a panel of six different genetic variations. These include engineered strains for rare codon supplementation, increased disulfide bond formation in the cytoplasm and novel vectors for secretion to the periplasm or culture medium. Combining these variants with expression construct truncations design, we report on parallel cloning and expression of more than 300 constructs representing 24 selected proteins; including full-length variants of human growth factors, interleukins and growth factor binding proteins. This rapid screening approach appears highly suitable for high-throughput efforts targeting either large sets of proteins or more focused investigations regarding individual high-profile targets.

WFIKKN1 and WFIKKN2 bind growth factors TGFβ1, BMP2 and BMP4 but do not inhibit their signalling activity

WFIKKN1 and WFIKKN2 are large extracellular multidomain proteins consisting of a WAP domain, a follistatin domain, an immunoglobulin domain, two Kunitz-type protease inhibitor domains and an NTR domain. Recent experiments have shown that both proteins have high affinity for growth and differentiation factor (GDF)8 and GDF11. Here we study the interaction of WFIKKN proteins with several additional representatives of the transforming growth factor (TGF)β family using SPR measurements. Analyses of SPR sensorgrams suggested that, in addition to GDF8 and GDF11, both WFIKKN proteins bind TGFβ1, bone morphogenetic protein (BMP)2 and BMP4 with relatively high affinity (K(d) ∼ 10(-6) m). To assess the biological significance of these interactions we studied the effect of WFIKKN proteins on the activity of GDF8, GDF11, TGFβ1, BMP2 and BMP4 using reporter assays. These studies revealed that WFIKKN1 and WFIKKN2 inhibited the biological activity of GDF8 and GDF11 in the nanomolar range, whereas they did not inhibit the activities of TGFβ1, BMP2 and BMP4 even in the micromolar range. Our data indicate that WFIKKN proteins are antagonists of GDF8 and GDF11, but in the case of TGFβ1, BMP2 and BMP4 they function as growth factor binding proteins. It is suggested that the physical association of WFIKKN proteins with these growth factors may localize their action and thus help to establish growth factor gradients in the extracellular space.

The growth hormone/insulin‐like growth factor‐I system in chronic heart failure and its interaction with adiponectin

The growth hormone/insulin‐like growth factor‐I system in chronic heart failure and its interaction with adiponectin

Psychiatric adverse effects of rimonobant in adults with Prader Willi syndrome

Background Prader Willi syndrome (PWS) without strict environmental modifications can lead to obesity associated with significant morbidity and mortality. In addition to increased appetite, these individuals have decreased energy expenditure with lower insulin like growth factor 1 (IGF1), which contributes to adiposity. No effective treatment is available for this condition. Endocannabinoid receptor CB1 antagonist, rimonobant, has been effective for treatment of obesity in adult subjects. Rimonabant promotes weight loss by multiple proposed mechanisms, including decreased appetite and lipogenesis, and increased energy expenditure. Therefore, we conducted this pilot study to evaluate the effect of rimonabant on body weight and composition of adults with PWS. Method This was a double blind placebo controlled study. Body weight, total fat mass, fasting ghrelin, leptin, IGF1 and insulin like growth factor binding protein (IGFBP-3) were collected at baseline, and after 90 and 180 days of treatment with placebo or 20 mg of rimonabant. Results Due to psychiatric adverse effects, 50% of subjects in the rimonabant group withdrew, and the study was terminated early ( N = 10) for safety concerns. There was a trend for weight loss, lower fat mass and higher IGF1 level at the end of study in this group. Leptin followed the fat mass and decreased with rimonabant treatment. Conclusion Rimonabant administration may be efficacious for weight loss in adults with PWS; unfortunately it is associated with an unacceptably high risk of psychiatric side effects. Future CB1 antagonists will need a better psychiatric profile before considered in the treatment of obesity in this genetic condition.

Cardiac Restricted Overexpression of Membrane Type-1 Matrix Metalloproteinase Causes Adverse Myocardial Remodeling following Myocardial Infarction

The membrane type-1 matrix metalloproteinase (MT1-MMP) is a unique member of the MMP family, but induction patterns and consequences of MT1-MMP overexpression (MT1-MMPexp), in a left ventricular (LV) remodeling process such as myocardial infarction (MI), have not been explored. MT1-MMP promoter activity (murine luciferase reporter) increased 20-fold at 3 days and 50-fold at 14 days post-MI. MI was then induced in mice with cardiac restricted MT1-MMPexp (n = 58) and wild type (WT, n = 60). Post-MI survival was reduced (67% versus 46%, p < 0.05), and LV ejection fraction was lower in the post-MI MT1-MMPexp mice compared with WT (41 ± 2 versus 32 ± 2%,p < 0.05). In the post-MI MT1-MMPexp mice, LV myocardial MMP activity, as assessed by radiotracer uptake, and MT1-MMP-specific proteolytic activity using a specific fluorogenic assay were both increased by 2-fold. LV collagen content was increased by nearly 2-fold in the post-MI MT1-MMPexp compared with WT. Using a validated fluorogenic construct, it was discovered that MT1-MMP proteolytically processed the pro-fibrotic molecule, latency-associated transforming growth factor-1 binding protein (LTBP-1), and MT1-MMP-specific LTBP-1 proteolytic activity was increased by 4-fold in the post-MI MT1-MMPexp group. Early and persistent MT1-MMP promoter activity occurred post-MI, and increased myocardial MT1-MMP levels resulted in poor survival, worsening of LV function, and significant fibrosis. A molecular mechanism for the adverse LV matrix remodeling with MT1-MMP induction is increased processing of pro-fibrotic signaling molecules. Thus, a proteolytically diverse portfolio exists for MT1-MMP within the myocardium and likely plays a mechanistic role in adverse LV remodeling.

Insulin-like growth factor binding protein-1 levels are increased in patients with IgA nephropathy

The mechanisms underlying the pathogenesis of immunoglobulin A (IgA) nephropathy (IgAN) are not well understood. In this study, we examined gene expression profiles in kidneys obtained from mice with high serum IgA levels (HIGA mice), which exhibit features of human IgAN. Female inbred HIGA, established from the ddY line, were used in these experiments. Serum IgA levels, renal IgA deposition, mesangial proliferation, and glomerulosclerosis were increased in 32-week-old HIGA mice in comparison to ddY animals. By microarray analysis, five genes were observed to be increased by more than 2.5-fold in 32-week-old HIGA in comparison to 16-week-old HIGA; these same five genes were decreased more than 2.5-fold in 32-week-old ddY in comparison to 16-week-old ddY mice. Of these five genes, insulin-like growth factor (IGF) binding protein (IGFBP)-1 exhibited differential expression between these mouse lines, as confirmed by quantitative RT-PCR. In addition, serum IGFBP-1 levels were significantly higher in patients with IgAN than in healthy controls. In patients with IgAN, these levels correlated with measures of renal function, such as estimated glomerular filtration rate (eGFR), but not with sex, age, serum IgA, C3 levels, or IGF-1 levels. Pathologically, serum IGFBP-1 levels were significantly associated with the severity of renal injury, as assessed by mesangial cell proliferation and interstitial fibrosis. These results suggest that increased IGFBP-1 levels are associated with the severity of renal pathology in patients with IgAN.

Grade-Specific Expression of Insulin-like Growth Factor–Binding Proteins-2, -3, and -5 in Astrocytomas: IGFBP-3 Emerges as a Strong Predictor of Survival in Patients with Newly Diagnosed Glioblastoma

Insulin-like growth factor (IGF)-binding protein (IGFBP) isoforms have been implicated in the pathogenesis of human neoplasms including glioma. In view of this, we evaluated the expression of IGFBP isoforms (IGFBP-2, -3, and -5) during malignant progression of astrocytoma and their prognostic significance in glioblastoma. The expression of IGFBP isoforms was analyzed in diffusely infiltrating astrocytomas by real-time quantitative PCR (n = 203) and immunohistochemistry (n = 256). Statistical methods were used to assess their grade-specific expression pattern and mRNA-protein intercorrelation. Survival analyses were done on a uniformly treated, prospective cohort of adult patients with newly diagnosed glioblastoma (n = 136) by using Cox regression models. The mean transcript levels of IGFBP-2 and -3 were significantly higher in glioblastomas (GBM) relative to anaplastic astrocytoma (AA), diffuse astrocytoma (DA), and controls whereas IGFBP-5 mRNA was higher in GBM relative to AA and controls (P < 0.05). By immunohistochemistry, the mean labeling index of all isoforms was significantly higher in GBM compared with AA, DA, and control (P < 0.05). A strong positive correlation was observed between their respective mRNA and protein expressions (P < 0.01). Multivariate analysis revealed IGFBP-3 expression (hazard ratio, 1.021; P = 0.030) and patient age (hazard ratio, 1.027; P = 0.007) to be associated with shorter survival in glioblastoma. This study shows the associations of IGFBP-2, -3, and -5 expression with increasing grades of malignancy in astrocytomas. IGFBP-3 is identified as a novel prognostic glioblastoma biomarker. The strong correlation between their mRNA and protein expression patterns suggests their role in the pathogenesis of these tumors. IGFBP isoforms have emerged as biomarkers with diagnostic and prognostic utility in astrocytomas.

Identification of proteins with altered expression in female Pregnancy Associated Plasma Protein‐A knockout mouse embryos

Our research examines the insulin‐like growth factor (IGF) signaling network. Pregnancy Associated Plasma Protein‐A (PAPP‐A), cleaves the Insulin‐like growth factor binding protein – 4 ability to sequester IGFs. We have examined the effects of PAPP‐A on protein expression in 18 day post‐conception mice embryos in a wild type/PAPP‐A knockout model. We have used 2‐D gel electrophoresis and proteomics technologies to examine protein expression differences between the knockout and wild‐type embryos. Three female wild‐type/knock out pairs were examined. Three successful trials were run for each of the embryo samples resulting in significant, reproducible results for each. The images from the wild‐type and knock out samples were compared in order to identify protein expression differences. Comparison of the wild‐type and knock out gels resulted in the identification of 6 protein spots out of 3500 total spots which showed significant change in protein expression. We have identified the proteins found in each of these 6 spots.

Low-intensity exercise training maintains adipokines in obese children

AbstractThe aim of the present study is to investigate the effects of a 12 weeks low-intensity exercise training on body composition, adipokines, and growth factors in normal (NG) and obese (OG) children. Maximal oxygen uptake (VO2max); body composition; adipokines consisting of adiponectin, retinol binding protein-4 (RBP4), and interleukin-6 (IL-6); and growth factors including insulin like growth factor-1 (IGF-1) and insulin like growth factor binding protein-3 (IGF-BP3) were measured before and after low-intensity exercise training program. Body composition parameters such as body weight, body mass index, body fat (%) and VO2 max were significantly different between NG and OG. Adiponectin levels in NG were increased after 12 weeks exercise training. In addition, our results showed that the concentrations of adiponectin, RBP4, IGF-1, and IGF-BP3 in OG were higher than those of NG. Adiponectin levels were significantly correlated with body fat (r = −0.545, p = 0.001) and VO2max (r = 0.368, p = 0.032) and RBP4 levels were significantly correlated with body fat (r = 0.371, p = 0.031) in all subjects. Exercise training improved adiponectin levels in NG subjects and maintained the levels of body fat, adipokines (adiponectin, RBP4), and growth factors (IGF-1, IGF-BP3) in OG subjects. The present study revealed that regular low-intensity exercise training is strongly associated with high adiponectin levels in healthy children. However, obese children did not exhibit any changes in the levels of adipokines and maintained body composition and growth factors.

Expression and localization of insulin‐like growth factor binding proteins in normal and proteinuric kidney glomeruli

Insulin-like growth factor I (IGF-I) acts on target cells in an endocrine and/or local manner through the IGF-I receptor (IGF-IR), and its actions are modulated by multiple IGF binding proteins (IGFBP). To elucidate the roles of local IGFBP in kidney glomeruli, the expression and localization of their genes were examined and compared with normal and proteinuric kidney glomeruli. A cDNA microarray database (MAd-761) was constructed using human kidney glomeruli and cortices. The gene expression levels of IGF-I, IGF-1R and IGFBP (1-10) were examined in glomeruli and cortices by polymerase chain reaction (PCR) and in situ hybridization (ISH), and the expression levels of IGFBP that were abundantly found in the glomerulus were compared between normal and proteinuric kidneys in rats and humans. IGFBP-2, -7 and -8 were demonstrated to be abundantly and preferentially expressed in the glomerulus. In PCR, the expression levels of the IGFBP-2, -7, -8 and -10 genes in glomeruli were shown to have more than doubled compared with their levels in the cortices. In ISH, the IGFBP-2, -7, -8 and -10 genes were found to be localized in glomerular cells including podocytes, and their increased expression was observed in inflammatory glomeruli. IGF-I gene expression was localized in glomerular podocytes, whereas the IGF-IR gene was expressed in glomerular podocytes and cortical tubular cells. In nephrotic rats, the expression of the IGFBP-10 gene was increased in glomerular podocytes; however, the expression levels of IGFBP-2, -7 and -8 did not change. IGFBP-2, -7, -8 and -10 are produced by normal and injured glomerular podocytes and may regulate local IGF-I actions in podocytes and/or cortical tubular cells in the kidney.