IGF-binding Protein-3 Levels Research Articles

Association between acromegaly and a single nucleotide polymorphism (rs2854744) in the IGFBP3 gene

BackgroundIt has been reported that the single nucleotide polymorphism (SNP) rs2854744 at the − 202 locus of insulin-like growth factor binding protein-3 (IGFBP3) is associated with serum levels and a number of malignancies. However, the effect of IGFBP3 gene polymorphism on acromegaly is less clear. Therefore, in the current study, we aimed to investigate whether the −202A/C polymorphism of IGFBP3 constitutes a risk factor for acromegaly.MethodsThe study included 102 acromegalic patients and 143 control subjects in Beijing Tiantan Hospital. The genotyping of IGFBP3 was carried out using the MassARRAY method. Serum IGFBP3 concentrations were also determined. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the associations of genetic polymorphisms with the development of acromegaly and its different subtypes.ResultsThe study revealed that the C allele of rs2854744 was associated with a reduced risk of acromegaly (OR 0.594, 95% CI 0.388–0.909), as well as with the female (OR 0.385, 95% CI 0.206–0.72), macroadenoma (OR 0.557, 95% CI 0.347–0.893) and monotherapy (OR 0.512, 95% CI 0.316–0.828) subgroups under the additive model. A higher serum IGFBP3 level was observed in patients with the AA genotype, but this difference was not significant (P = 0.331).ConclusionThis study is one of the first to show that the IGFBP3 polymorphism may have an influence on serum levels and that the C allele of rs2854744 is associated with a reduced risk of acromegaly. This correlation was more prominent in females, those with large tumours and those treated with monotherapy in a Chinese population. Genetic polymorphism of IGFBP3 may be involved in the development of acromegaly.

Insulin like growth factor binding protein 2 (IGFBP-2) for risk prediction in patients with severe aortic stenosis undergoing Transcatheter Aortic Valve Implantation (TAVI)

IntroductionSevere aortic stenosis (AS) caused by degenerative calcification is the most frequent acquired valvular heart disease worldwide and mortality rates are considerably high. Transcatheter Aortic Valve Implantation (TAVI) is a well-established method for valve replacement in high risk patients with AS. However, there is a lack of reliable predictors for patients undergoing TAVI since commonly used scores were developed for surgical populations. Materials and methods208 patients subjected to TAVI were included in this study. Plasma samples were obtained before TAVI and were evaluated for IGFBP-2 using commercially available ELISA kits. IGFBP-2 levels were analyzed for their ability for risk prediction after TAVI. ResultsIGFBP-2 levels measured before TAVI correlated significantly with left ventricular ejection fraction, EUROSCORE and other functional and prognostic parameters like the 6-minute walking test. When patients were retrospectively divided in two groups with a cut-off of serum IGFBP-2 levels of 275 ng/ml, IGFBP-2 was a strong predictor for 30-day and one-year mortality (3% vs. 11%, p = 0.05 and 18.2% vs. 46.2%; p < 0.001 respectively). Compared to an EUROSCORE above 20 or an STS score cut-off above 8, IGFBP-2 plasma levels above 275 ng/ml outperformed the established risk score for prediction of one-year mortality as assessed by NRI (0.65 95% CI 0.37–0.94; p < 0.001 and 0.54 95% CI 0.25–0.82; p < 0.001, respectively). ConclusionsOur results indicate that IGFBP-2 could serve as new outcome predictor for patients undergoing TAVI procedure. By providing additional information to the commonly used EUROSCORE, IGFPB-2 analysis could further assist Heart Team decision making.

Effects of insulin-like growth factor binding protein 3 on apoptosis of cutaneous squamous cell carcinoma cells.

BackgroundCutaneous squamous cell carcinoma (CSCC) is the second most common carcinoma worldwide. Clinical treatment for patients with CSCC remains non-ideal. Insulin-like growth factor binding protein 3 (IGFBP3), a member of the insulin-like growth (IGF) system, participates in several biological processes, including cellular proliferation and apoptosis. Here, we explored the functional role of IGFBP3 in apoptosis and proliferation of A431 cells, a human CSCC cell line.Materials and methodsDifferential expression analysis, immunohistochemistry, immunoblotting, TUNEL assay, and CCK8 assay techniques were used to investigate the IGFBP3 expression levels in both A431 cells and CSCC tissue surgically obtained from humans as well as to explore the functional role of IGFBP3 in the apoptosis and proliferation of A431 cells.ResultsBy using normal epidermal keratinocytes for comparison, we identified the top 10 ranked differentially upregulated genes expressed in human cutaneous squamous cell carcinoma cell lines. Among these 10 genes, IGFBP3 was ranked number 1. By using immunohistochemistry, we found that the expression level of IGFBP3 was significantly elevated in CSCC tissue compared with that in normal human skin tissue. Knockdown of IGFBP3 in A431 cells by transfection with IGFBP3-specific siRNA markedly altered the expression of proteins that contribute to apoptosis via mitochondrial pathways, significantly suppressing the expression of Bax and active caspase-3, while significantly increasing B-cell lymphoma-2 expression. TUNEL assay confirmed the effect of knockdown of IGFBP3 on the apoptosis as well. In addition, knockdown of IGFBP3 inhibited the proliferation of A431 cells.ConclusionIGFBP3 is overexpressed in both CSCC cell lines and tissue. Knockdown of IGFBP3 enhanced the apoptosis via a mitochondrial pathway and inhibited the proliferation of A431 cells. These findings indicate that IGFBP3 may be a biomarker and a potential therapeutic target for CSCC.

C-type natriuretic peptide improves growth retardation in a mouse model of cardio-facio-cutaneous syndrome.

Cardio-facio-cutaneous (CFC) syndrome, a genetic disorder caused by germline mutations in BRAF, KRAS, MAP2K1 and MAP2K2, is characterized by growth retardation, heart defects, dysmorphic facial appearance and dermatologic abnormalities. We have previously reported that knock-in mice expressing the CFC syndrome-associated mutation, Braf Q241R, showed growth retardation because of gastrointestinal dysfunction. However, other factors associated with growth retardation, including chondrogenesis and endocrinological profile, have not been examined. Here, we show that 3- and 4-week-old BrafQ241R/+ mice have decreased body weight and length, as well as reduced growth plate width in the proximal tibiae. Furthermore, proliferative and hypertrophic chondrocyte zones of the growth plate were reduced in BrafQ241R/+ mice compared with Braf+/+ mice. Immunohistological analysis revealed that extracellular signal-regulated kinase (ERK) activation was enhanced in hypertrophic chondrocytes in BrafQ241R/+ mice. In accordance with growth retardation and reduced growth plate width, decreased serum levels of insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3) were observed in BrafQ241R/+ mice at 3 and 4 weeks of age. Treatment with C-type natriuretic peptide (CNP), a stimulator of endochondral bone growth and a potent inhibitor of the FGFR3-RAF1-MEK/ERK signaling, increased body and tail lengths in Braf+/+ and BrafQ241R/+ mice. In conclusion, ERK activation in chondrocytes and low serum IGF-1/IGFBP-3 levels could be associated with the growth retardation observed in BrafQ241R/+ mice. Our data also suggest that CNP is a potential therapeutic target in CFC syndrome.

Insulin-Like Growth Factor Binding Protein 2 Is Associated With Biomarkers of Alzheimer’s Disease Pathology and Shows Differential Expression in Transgenic Mice

There is increasing evidence that metabolic dysfunction plays an important role in Alzheimer’s disease (AD). Brain insulin resistance and subsequent impairment of insulin and insulin-like growth factor (IGF) signaling are associated with the neurodegenerative and clinical features of AD. Nevertheless, how the brain insulin/IGF signaling system is altered in AD and the effects of these changes on AD pathobiology are not well understood. IGF binding protein 2 (IGFBP-2) is an abundant cerebral IGF signaling protein and there is early evidence suggesting it associates with AD biomarkers. We evaluated the relationship between protein levels of IGFBP-2 with cerebrospinal fluid (CSF) biomarkers and neuroimaging markers of AD progression in 300 individuals from across the AD spectrum. CSF IGFBP-2 levels were correlated with CSF tau levels and brain atrophy in non-hippocampal regions. To further explore the role of IGFBP2 in tau pathobiology, we evaluated the expression of IGFBP2 in different human and mouse brain cell types and brain tissue from two transgenic mouse models: the P301L-tau model of tauopathy and TASTPM model of AD. We observed significant differential expression of IGFBP2 in both transgenic mouse models relative to wild-type mice in cortex but not in hippocampus. In both humans and mice, IGFBP2 is most highly expressed in astrocytes. Taken together, our findings suggest that IGFBP-2 may be linked to tau pathology and provides further evidence for a relationship between metabolic dysregulation and neurodegeneration. Our results also raise the possibility that this relationship may extend beyond neurons.

Combined aerobic exercise and high-intensity respiratory muscle training in patients surgically treated for non-small cell lung cancer: a pilot randomized clinical trial.

Lung resection surgery further decreases exercise capacity and negatively affects respiratory muscle function in patients with non-small cell lung cancer (NSCLC). The best design for exercise interventions in these patients has not been determined yet. To assess the impact of aerobic exercise and high-intensity respiratory muscle training on patient outcomes following lung cancer resection surgery. Prospective, single-blind, pilot randomized controlled trial. Outpatient cardiopulmonary rehabilitation unit of two university hospitals. Thirty-seven patients with NSCLC after tumor resection. Patients were randomly assigned to exercise training or usual post-operative care. The training program consisted of aerobic exercises and high-intensity respiratory muscle training (24 supervised sessions, 3 per week, 8 weeks). Primary outcome was exercise capacity assessed with peak oxygen uptake (VO2peak) during cardiopulmonary exercise test. Secondary outcomes included changes in respiratory muscle strength, levels of serum insulin growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3), and quality of life assessed with the European Organization for Research and Treatment of Cancer (EORTC QLQ-C30) questionnaire. The 8-week training program was associated with significant improvement in VO2peak (2.13 mL/Kg/min [95%CI 0.06 to 4.20]), maximal inspiratory and expiratory pressures (18.96 cmH2O [95% CI 2.7 to 24.1] and 18.58 cmH2O [95% CI 4.0 to 33.1], respectively) and IGFBP-3 (0.61 µg/mL [%95 CI 0.1 to 1.12]). No significant differences were observed in the EORTC QLQ-C30. An 8-week exercise program consisting of aerobic exercise and high-intensity respiratory muscle training improved exercise capacity, respiratory muscle strength, and serum IGFBP-3 levels in NSCLC patients after lung resection. There was no impact on the other outcomes assessed. A combination of aerobic exercise and respiratory muscle training could be included in the rehabilitation program of deconditioned patients with NSCLC after lung resection surgery.

Influence of neonatal anthropometry on the comorbidities of the obese patient

Small for gestational age (SGA) newborns show an increased risk of several diseases such as short stature, childhood obesity, and metabolic comorbidities. The study included 883 obese patients (47% females/53% males; mean age: 10.33±3.32 years, BMI:+3.93±1.42 SD), with prospective follow-up (5 years) of growth, recording adult height when achieved (n=104). Comparisons at diagnosis, according to their neonatal anthropometry; adequate for gestational age (AGA; n=810) vs. SGA (n=73), were performed for the following features: age at their first visit, standardised height for target height (Z-score), bone age, adult height prediction, BMI (Z-score), glycaemia, insulinaemia, HOMA, total cholesterol, HDL, LDL, triglycerides, 25-OH-vitamin D, area under the curve (AUC) for glucose and insulin in the OGTT, LDL/HDL and triglyceride/HDL ratio, insulin-like growth factor (IGF-I) and IGF-binding protein 3 (IGFBP-3) serum levels. Despite similar BMI-SDS, ethnic, and pubertal distribution in both groups, patients with SGA showed more severe changes in lipid profile (triglyceride and triglyceride/HDL ratio, both P<.05) and carbohydrate metabolism (higher glycaemia, glucose and insulin AUCs, HOMA, HbA1c and lower whole-body insulin sensitivity index (WBISI), all P<.05) and lower 25-OH vitamin D levels (P<.05). They also showed a poorer adult height prediction (adjusted for target height) (P<.01), despite a similar degree of advance in skeletal maturation and similar IGF-I and IGFBP-3 levels than AGA patients. The background of SGA neonatal anthropometry is associated with a higher prevalence and severity of metabolic comorbidities and to a poorer adult height prediction in obese children and adolescents.

Abstract 1095: Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) regulates mitochondrial dynamics, EMT and angiogenesis in progression of prostate cancer

Abstract Prostate cancer (PCa) is a major epithelial cancer among men and with the second highest incidence rate, worldwide. The high ratio of IGF-1/IGFBP-3 correlates with increased risk of many cancers including prostate cancer. In present study, we have evaluated the role of IGFBP-3 and effect of fisetin, a phytochemical, active constituent of strawberry, apple etc. in the progression of prostate cancer. The exogenous expression of IGFBP-3 moderately decreased the cell growth and it further decreased with addition of fisetin in DU145 and LNCaP cells. The restoration of IGFBP-3 in DU145 cells inhibited the clonogenic potential which is further decreased with fisetin treatment. Increased ROS content was observed in IGFBP-3 overexpression condition, however fisetin treatment reversed the ROS content in DU145, shows antioxidant behaviour. Morphological examination of mitochondria revealed that IGFBP-3 overexpression destabilizes the mitochondrial dynamics by reduction in active DRP1 level which has been reversed by fisetin treatment. We evaluated the effect on mitochondrial mass which was decreased in IGFBP-3 overexpressing DU145 cells which further decreased with addition of fisetin at 12 and 24 h. IGFBP-3 overexpression decreased the migratory potential of DU145 cells under normoxic conditions and under hypoxic condition it increased the migration of DU145 cells. Furthermore, IGFBP-3 overexpression decreased the VEGF expression as compared to vector control which can inhibit the expansion of tumor cells. Under the hypoxic conditions (1% oxygen), cells showed increased levels of IGFBP-3 when compared to normoxic conditions (21% Oxygen) in time dependent manner. The down-regulation of IGFBP-3 in PC3 cells, increased the expression of E-cadherin, a biomarker of epithelial to mesenchymal transition. The wound scratch assay showed the pro-migratory role of IGFBP-3 in PC3 cells and treatment with fisetin inhibited the migration of these cells under the hypoxic condition. The knockdown of IGFBP3 resulted in the decreased invasive potential of PC3 in comparison to cells in hypoxic state. Together with these observation, IGFBP-3 have shown biphasic character depending on normoxic and hypoxic condition in controlling the prostate cancer progression. Citation Format: Arpit Dheeraj, Dhanir Tailor, Gagan Deep, Rana P. Singh. Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) regulates mitochondrial dynamics, EMT and angiogenesis in progression of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1095.

IGFBP2 Is Increased after Gastric Bypass in Humans—Potential Impact on Hepatic Metabolism

To identify molecular mechanisms contributing to postoperative metabolic improvements after Roux-en-Y gastric bypass (RYGB), we performed comprehensive proteomic analysis of fasting human plasma samples obtained from the SLIMM-T2D longitudinal clinical trial, which randomized obese individuals with T2D to RYGB surgery or a one-year intensive medical diabetes and weight management (DWM) program, and followed them for 3 years. Somalogic proteomic analysis was performed on plasma collected in the fasting state at baseline and during longitudinal follow-up, and proteins differentially abundant in RYGB vs. DWM at each time point were identified. The protein with highest magnitude of differential abundance at 3 years was insulin-like growth factor binding protein 2 (IGFBP2), upregulated by 2.2-fold in RYGB vs. DWM (p=4.37E-06); differences were confirmed by ELISA. IGFBP2 inversely correlated at 3 years with BMI (r=-0.74, p=5.31E-05) and HbA1c (r=-0.68, p=0.00004). Notably, IGFBP2 levels were increased at the first postoperative study visit (10% weight loss) following RYGB or at similar weight loss for the DWM group, suggesting an early weight-independent contribution. IGFBP2 is predominantly expressed in liver and upregulated after RYGB in mice (2.8-fold at 8 weeks, GSE68812). To identify IGFBP2-dependent mechanisms contributing to improved hepatic metabolism, we overexpressed mouse IGFBP2 or control vector in mouse AML12 hepatocytes, achieving a 6-fold increase in IGFPB2 protein. qPCR revealed 15-30% downregulation of lipogenic genes (e.g., Fasn, Srebp1) with a 2-fold increase in expression of genes regulating fatty acid oxidation (e.g., Ppara, Ppargc1a). Analysis of metabolism (Seahorse flux analyzer) revealed increased fatty acid oxidation (3-fold, p&amp;lt;0.01 for IGFBP2 vs. control). In conclusion, increased IGFBP2 expression may contribute to improved hepatic lipid oxidative metabolism, and thus induce systemic metabolic improvement after RYGB surgery. Disclosure Y. Yuchi: None. W. Cai: None. T. Takagi: None. H. Pan: None. J. Dreyfuss: None. K. Foster: None. A.H. Vernon: None. D.C. Simonson: Advisory Panel; Self; GI Windows, Inc.. Stock/Shareholder; Self; GI Windows, Inc.. Stock/Shareholder; Spouse/Partner; Phase V Technologies, Inc. A. Goldfine: Employee; Self; Novartis AG. A. Hoeflich: None. M.E. Patti: Research Support; Self; Janssen Pharmaceuticals, Inc.. Other Relationship; Self; Xeris Pharmaceuticals, Inc.. Research Support; Self; Ethicon US, LLC., Coviden, MedImmune. Other Relationship; Self; Novo Nordisk Inc., XOMA Corporation, AstraZeneca, Nestlé. Research Support; Self; Dexcom, Inc.. Consultant; Self; Eiger BioPharmaceuticals.

IGFs and IGF-Binding Proteins in Pregnancy and Gestational Diabetes Mellitus

The insulin-like growth factor (IGF) axis is involved in the regulation of growth and metabolism; however, little is known about its role in the development of gestational diabetes mellitus (GDM). The aim of our study was to determine serum IGF-1, IGF-2 and selected IGF binding protein (IGFBP) levels and their mRNA expression in subcutaneous (SAT) and visceral adipose tissue (VAT) and placenta in the context of pregnancy and GDM. Thirty-seven pregnant females - 21 with GDM (GDM group) and 16 without GDM (P group) - and 15 age-matched non-pregnant control females (NP group) were included into the study. Blood samples were taken in 28th-32th and 36th-38th gestational week and 6-12 months after delivery (GDM and P group) or before diagnostic laparoscopy (NP group). SAT, VAT and placental samples were obtained during delivery or surgery, respectively. Compared with NP group serum IGF-1, IGFBP-1 and 3 were increased in both GDM and P subjects reaching maximum levels in 38th-39th gestational week. IGF-2 was elevated only in GDM group culminating 6 months after delivery (745.1±24.7 vs. 909.2±62.8 vs. 998.7±92.7 ng/ml, p=0.017 for GDM and 726.9±28.4 vs. 791.2±44.2 vs. 748.9±58.4 ng/ml, p=0.341 for P group, respectively). IGFBP-3 was higher and IGFBP-4 was decreased in GDM vs. P group during the whole study (IGFBP3: 631.0±22.9 vs. 536.9±15.4 ng/ml, p=0.003 for GDM vs. P group; IGFBP4: 14.79±2.71 vs. 22.78±2.94 ng/ml, p&amp;lt;0.001 for GDM vs. P group). mRNA expression of IGF-1, IGFBP-3, 4 and 5 was increased in SAT, while IGF-2 and IGFBP-4 mRNA was elevated in VAT in GDM and P relative to NP group. Placental mRNA expression of IGF-2, IGF-2 receptor, IGFBP-3 and 4 was higher in GDM compared with P group. In conclusion, females with GDM had increased serum IGF-2, IGFBP-3 and reduced IGFBP-4 levels and elevated placental mRNA expression of several components of IGF axis compared with pregnant women without GDM. These changes might play a role in the development of GDM. Disclosure K. Anderlová: None. P. Simjak: None. A. Cinkajzlova: None. J. Klouckova: None. H. Kratochvilova: None. Z. Lacinová: None. P. Kaválková: None. H. Krejci: None. M. Mraz: None. M. Haluzik: None. M. Krsek: None.

Expression of Insulin-like Growth Factor Binding Protein-3 and Regulation of the Insulin-like Growth Factor-I Axis in Pig Testis

The stem cell niche is a complex unit comprising key components, such as the extracellular matrix and various paracrine factors, which regulate the differentiation of adult stem cells. In our previous study, we established pig spermatogonial stem cells (pSSCs) in culture and identified the expression of insulin-like growth factor binding protein-3 (IGFBP-3) in pSSCs. The present study investigated not only the expression of IGFBP-3, but also its possible role in pSSCs. In this study, IGFBP-3-expressing cells responded positively to protein gene product 9.5 (PGP9.5), which is a marker for pig spermatogonia. IGFBP-3 expression was significantly increased in 60-dayold pig testes. Additionally, the expression levels of insulinlike growth factor I (IGF-I) and its receptor (IGF-IR) were observed in pSSCs and pig Sertoli cells (pSCs). Furthermore, IGF-I treatment enhanced the proliferation of pSCs and pSSCs when they were co-cultured. Blocking the IGF-I pathway using a specific IGF-IR inhibitor dramatically reduced the proliferation of pSCs. In addition, when heparan sulfate was used to sequester IGFBP-3 from IGF-I binding, a significant increase in the proliferation of pSCs was observed. Exogenous IGF-I treatment also increased the expression level of IGFBP-3 in cultured pSSCs. Furthermore, pSSCs grew well in IGF-I-treated pSC conditioned media. In summary, IGF-I and IGF-IR signaling are important for the proliferation of pSCs, and the germ cell-derived IGFBP-3 had an inhibitory effect on the mitotic activity of IGF-I in pSCs.

Expression of MyoD, insulin like growth factor binding protein, thioredoxin and p27 in secondarily overacting inferior oblique muscles with superior oblique palsy

BackgoundTo identify and compare specific protein levels between overacting inferior oblique (IO) muscles in superior oblique (SO) palsy patients and normal IO muscles.MethodsWe obtained 20 IO muscle samples from SO palsy patients with IO overaction ≥ + 3 who underwent IO myectomies (IOOA group), and 20 IO samples from brain death donors whose IO had functioned normally, according to their ophthalmological chart review (control group). We used MyoD for identifying satellite cell activation, insulin-like growth factor binding protein 5 (IGFBP5) for IGF effects, thioredoxin for oxidative stress, and p27 for satellite cell activation or oxidative stress in both groups. Using immunohistochemistry and Western blot, we compared expression levels of the four proteins (MyoD, IGFBP5, thioredoxin, and p27).ResultsLevels of thioredoxin and p27 were decreased significantly in the IOOA group. MyoD and IGFBP5 levels showed no significant difference between the groups.ConclusionsBased on these findings, the overacting IOs of patients with SO palsy had been under oxidative stress status versus normal IOs. Pathologically overacting extraocular muscles may have an increased risk of oxidative stress compared with normal extraocular muscles.

Increased Serum IGFBP-1 and Reduced Insulin Resistance After Roux-En-Y Gastric Bypass in Chinese Patients with Type 2 Diabetes: a 6-Month Follow-Up.

This study aimed to measure changes of insulin-like growth factor binding protein-1 (IGFBP-1) in patients with type 2 diabetes mellitus (T2D) following gastric bypass surgery. A total of 10 patients with T2D underwent laparoscopic Roux-en-Y gastric bypass (RYGB) surgery. Patient height, weight, waist circumference, and hip circumference were measured pre- and post-operatively at 6months after surgery. Serum samples were collected at 6months after surgery to determine fasting blood glucose, glycosylated Hb, fasting insulin, C-peptide, and 2-h postprandial blood glucose, insulin, and C-peptide. Serum was collected at 3days and 6months after surgery and IGFBP-1 level determined using ELISA. Serum samples were also collected from 30 healthy weight subjects and 27 overweight control subjects. Body weight, BMI, and waist circumference were significantly improved following RYGB surgery. Blood glucose, fasting blood glucose, 2-h postprandial blood glucose, and HbA1c were also significantly improved. Fasting C-peptide and 2-h postprandial C-peptide were non-significantly reduced. Serum IGFBP-1 significantly increased at 3days and 6months after RYGB surgery. Pre-operative serum IGFBP-1 was not significantly different from healthy weight subjects or overweight subjects. Increased serum level of IGF-binding proteins after RYGB in 6months is increased post-surgery compared with overweight and healthy weight controls. IGFBP-1 may serve as part of new supplementary criteria for surgical selection and for defining the success of RYGB.

Overexpression of Insulin‐like Growth Factor Binding Protein 1 (IGFBP1) Generates Tamoxifen Resistance in Breast Cancer Cells

Tamoxifen, a selective estrogen receptor modulator and antagonist for estrogen receptor alpha (ERα) in breast tissue, is a commonly prescribed adjuvant treatment for patients presenting with ERα‐positive breast cancer. Acquired resistance to tamoxifen remains a clinically relevant challenge for many patients receiving treatment and some patients with ERα‐positive breast cancer are innately resistant to tamoxifen treatment. The molecular mechanisms underlying both acquired and innate tamoxifen resistance are not well understood. Previous studies have shown that, in addition to ERα inhibition, tamoxifen activates the G‐protein‐coupled estrogen receptor 1 (GPER1) and activation of this receptor is associated with the development of tamoxifen resistance. GPER1 mediates the extracellular accumulation of the insulin‐like growth factor binding protein 1 (IGFBP‐1) after tamoxifen treatment resulting in the inhibition of the IGF‐1R signaling in breast cancer cells. We hypothesize sustained exposure of breast cancer cells to IGFBP‐1 will result in the development of tamoxifen resistance. Stable transfection of an IGFBP‐1 expression vector was used for sustained exposure of MCF‐7 breast cancer cells. IGF‐1R expression was decreased in MCF‐7 cells stably transfected with the IGFBP‐1 expression vector similar to IGF‐1R expression in tamoxifen resistant breast cancer cells. Similar to tamoxifen‐resistant MCF‐7 cells, the IGFBP‐1 overexpressing MCF‐7 cells also have elevated levels of activated ERK1/2. Finally, cell viability assays revealed that sustained IGFBP‐1 overexpression decreased breast cancer sensitivity to tamoxifen treatment. Taken together, these results suggest that elevated levels of IGFBP‐1 contribute to the development of tamoxifen resistance in breast cancer cells.Support or Funding InformationResearch reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103451.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

High serum IGF-1 levels are associated with pregnancy loss following frozen-thawed euploid embryo transfer cycles

An elevated level of insulin growth factor (IGF-1) in rat uterine fluid has been shown to exert detrimental effects of embryo development possibly leading to an increase in pregnancy loss. Interestingly, the administration of somatostatin to rats undergoing superovulation reduced IGF-1 levels in uterine luminal fluid and thus reversed its deleterious effects on embryo development and increased the number of normal embryos. Therefore, we investigated whether serum levels of IGF-1 correlate with the incidence of pregnancy loss following IVF. To account for aneuploidy and the effect of hormonal supplementation on serum IGF levels, we only included natural frozen-thawed euploid embryo transfer (N-FET) cycles. Sera collected in the follicular phase (cycle day 10) were tested for levels of IGF-1, IGF-2, and IGF-binding protein 1 (IGFBP-1) using quantitative ELISA. A total of 156 N-FET cycles were included: 120 resulted in a live birth whereas 36 led to a first trimester pregnancy loss. Women with a pregnancy loss had significantly higher serum IGF-1 levels compared to those who achieved a live birth (18.0 ± 1.1 vs. 14.6 ± 0.7 ng/mL, respectively). The two groups had comparable serum IGF-2 and IGFBP-1 levels. There was no significant difference in maternal age, body mass index, gravidity, parity, number of prior miscarriages, peak endometrial thickness, or infertility diagnosis between the two groups. In conclusion, women undergoing euploid blastocyst transfer with elevated serum IGF-1 concentrations may be at increased risk of pregnancy loss. This may constitute a novel molecular explanation of pregnancy loss of euploid conceptus.

Serum IGFBP-2 levels are associated with reduced insulin sensitivity in obese children.

Insulin-like growth factor binding protein 2 (IGFBP-2) may represent a critical link between body composition and insulin sensitivity. We investigated the relationship between circulating IGFBP-2 levels, body composition, insulin sensitivity, energy intake and physical activity in children with obesity. Children were recruited via the Weight Management Service at the Royal Children's Hospital, Melbourne, as part of the Childhood Overweight BioRepository of Australia (COBRA). Comprehensive anthropometric, biochemical and environmental data were collected and compared to serum IGFBP-2 levels (measured by enzyme-linked immunosorbent assay). Multiple regression modelling was used to assess the influence of circulating IGFBP-2 levels on anthropometric and biochemical measures. One hundred and ninety-four children were included in this study (46% male). Circulating IGFBP-2 negatively correlated with age, anthropometric measures, blood pressure and insulin concentration. Positive associations were observed between insulin sensitivity index-homeostasis model assessment (ISI-HOMA) and serum IGFBP-2. In multiple regression modelling, IGFBP-2 significantly contributes to variance in systolic blood pressure (-19%, P < 0.05), circulating triglycerides (-16%, P < 0.05) and ISI-HOMA (18%, P < 0.05). No associations were observed between dietary energy intake or physical activity and IGFBP-2 levels. Circulating IGFBP-2 levels in children with obesity correlate inversely with body mass and markers of metabolic dysfunction, and positively with insulin sensitivity. These findings suggest that reduced levels of IGFBP-2 may play an important role in the pathogenesis of obesity complications in early life.

Association of insulin-like growth factor-1 and IGF binding protein-3 with 25-hydroxy vitamin D in pre-pubertal and adolescent Indian girls.

There is a high prevalence of vitamin D deficiency (VDD) in India. Molecular mechanisms suggest a strong relationship between vitamin D and growth factors. However, there is a paucity of literature with regard to a relationship between insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and vitamin D particularly in subjects with VDD. The objective of the study was to assess the relationship between growth factors and serum vitamin D-parathormone (PTH) status in school girls and study the impact of vitamin D supplementation on growth factors in pre-pubertal girls with VDD. Our study subjects were apparently healthy school girls aged 6-18 years. The baseline height, weight, body mass index (BMI), pubertal status, serum 25-hydroxy vitamin D (25OHD), PTH, IGF-1 and IGFBP-3 were assessed in 847 girls aged 6-18 years and in 190 pre-pubertal girls with VDD following supplementation. The mean age, BMI and serum 25OHD of girls were 11.5±3.2 years, 18.7±4.8 kg/m2 and 9.9±5.6 ng/mL, respectively. VDD was observed in 94.6% of girls. Unadjusted serum IGF-1 levels and IGF-1/IGFBP-3 molar ratio were significantly higher in girls with severe VDD as compared to girls with mild-to-moderate VDD. However, these differences disappeared when adjusted for age, height or sexual maturation. The serum IGF-1 and IGFBP-3 levels increased significantly post supplementation with vitamin D. There were no differences in serum IGF-1 levels and the IGF-1/IGFBP-3 molar ratio among VDD categories when adjusted for age, height and sexual maturation in girls. Vitamin D supplementation resulted in a significant increase in serum IGF-1 levels in VDD pre-pubertal girls.

Abstract P1-07-23: The quality and quantity of visceral fat tissue are associated with insulin resistance and survival outcome after chemotherapy for patients with early-stage breast cancer

Abstract Background: Obesity and insulin resistance are associated with inferior levels of chemosensitivity and overall prognosis for breast cancer (BC) treatment. Recent studies suggest that the quality and quantity of visceral adipose tissue (VAT) play a significant role in adipocyte function, and are related to insulin resistance. We therefore tested the hypothesis that high amount and low quality of VAT worsen treatment outcomes via insulin resistance mechanisms. Patients and Methods: We examined two independent studies: a cross-sectional study (cohort 1) and a retrospective study (cohort 2). Cohort 1 included 106 women with early-stage BC who were undergoing surgery. Patients with normal weight (17.5&amp;lt; body mass index [BMI, kg/m2] ≤25, n = 53) and overweight/obese patients (BMI &amp;gt;25, n = 53) were selected by a pair-matching method. Insulin resistance was evaluated by HOMA-R: fasting insulin (microU/L) × fasting glucose (nmol/L)/22.5. And insulin-like growth factor (IGF) family including IGF-1 and IGF-binding protein 3 (IGFBP3) were measured before beginning treatment. The amounts of visceral fat (aVAT) was measured by 3-dimensional volumetric software using the stocked computed tomography (CT) imaging data. The quality of VAT was assessed based on the mode value of CT Hounsfield Unit of VAT (VAT-HU) at navel level of CT axial view. The association between the former variables and the quality and quantity of VAT was analyzed. Cohort 2 included 271 patients who received chemotherapy in the neo-adjuvant (NAC) or adjuvant setting. Imaging analysis was performed in the same way, and the association between those values and survival outcome after chemotherapy was analyzed by retrospective chart review. Results: In cohort 1, aVAT was significantly correlated with serum insulin and HOMA-R levels (Pearson's R 0.44 and 0.42, respectively; P&amp;lt;0.05). On comparing the two groups divided by BMI, the levels of IGF-1 and IGFBP3 were not significantly different between the normal weight and the overweight/obese groups (P = 0.31 and 0.77, respectively). However, the overweight/obese group demonstrated significantly higher HOMA-R (P&amp;lt;0.05). In cohort 2, aVAT was significantly correlated with BMI (P&amp;lt;0.05). In a multivariate analysis, pathological complete responses were not associated with aVAT (P = 0.60). After a median follow-up of 112 months, tertile stratification revealed that the third tertile of aVAT had a significantly shorter distant disease free survival (DDFS) in the NAC setting (p&amp;lt;0.05). When adjusted by covariates in the Cox proportional regression model, aVAT and VAT-HU demonstrated significant contribution to a worsened DDFS ([p&amp;lt;0.05, hazard ratio {HR} 1.39; 95% confidence interval {CI} 1.11 to 1.75] and [p&amp;lt;0.05, HR 1.20, 95% CI 1.01 to 1.43], respectively). Conclusions: Our study found that high amounts and low quality of VAT worsen treatment outcomes. Furthermore, we found that insulin resistance was related to those two factors. Although further validation is needed, our present work suggests the importance of evaluating the quality and quantity of visceral fat for estimating insulin resistance and treatment outcomes after chemotherapy for patients with early-stage BC. Citation Format: Iwase T, Sangai T, Nagashima T, Sakakibara M, Fujimoto H, Sawabe Y, Nagashima K, Otsuka M. The quality and quantity of visceral fat tissue are associated with insulin resistance and survival outcome after chemotherapy for patients with early-stage breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-23.

Insulin-like growth factor-1 (IGF1) in systemic lupus erythematosus: relation to disease activity, organ damage and immunological findings.

Background Insulin growth factor-1 (IGF1) activates cell proliferation pathways and inhibits apoptosis. IGF1 is involved in tumour growth and required for T-cell independent activation of B cells. Activated B cells and autoantibody production are a hallmark of systemic lupus erythematosus (SLE). To investigate the possible role of IGF1 in SLE, we studied IGF1 across clinical characteristics, immunological biomarkers, disease activity and organ damage in SLE patients. Method In a cross-sectional study, we collected clinical characteristics, medication, disease activity (SLEDAI-2K) and organ damage (SDI) for 94 SLE patients. Autoantibodies and cytokines were measured by ELISA, and levels of IGF1 and IGF binding protein 3 (IGFBP3) by chemiluminescence. Free IGF1 was estimated by the IGF1:IGFBP3 ratio. Healthy controls served as a comparator group. Results There was a significant age-related decline in IGF1, IGFBP3 and free IGF1 (IGF1:IGFBP3 ratio) that was similar in SLE patients and controls with very few outliers. Free IGF1 was inversely related to blood pressure (Rs -0.327, p < 0.01) and HbA1c (Rs -0.31, p < 0.01). Free IGF1 was higher in disease-modifying antirheumatic drug-treated patients ( p < 0.01), but there was no significant association between the IGF1 axis and autoantibody profiles, cytokine levels or SLEDAI-2K or SDI categories. IGF1 correlated inversely with BAFF level and B, natural killer and CD8 + cell counts. Conclusion Free IGF1 levels in SLE patients declined appropriately with age. IGF1 levels were not associated with disease activity, severity or autoantibody levels in SLE. Free IGF1 had positive metabolic effects in SLE and may play an indirect role in dampening the cellular immune response by downregulating B- and T-cell activity.

Hormonal responses following eccentric exercise in humans.

Mechanically overloaded muscle and its subsequent damage are strong stimuli for eliciting acute hormonal changes, while the muscle adaptation which occurs following exercise-induced muscle damage may involve complex hormonal responses before the completion of muscle regeneration. The purpose of this study was to investigate systemic responses of various hormones, as well as secreted proteins that are exercise-regulated and associated with muscle adaptation, for several days after eccentric exercise-induced muscle damage in humans. Nine young male volunteers performed 50 maximal eccentric muscle actions using the knee extensor muscles of both legs. Blood samples were drawn before and at 6, 48 and 120 hours post exercise and serum levels of growth hormone (GH), insulin-like growth factor binding protein-3 (IGFBP-3), cortisol, prolactin, thyroid-stimulating hormone (TSH), free thyroxine (fT4), irisin, follistatin and sclerostin were measured. Myoglobin (Mb) concentration and lactate dehydrogenase (LDH) activity were also evaluated as indirect markers of muscle damage. Significant alterations in Mb and LDH were observed over time after eccentric exercise (p=0.039-0.001). A late serum increase in fT4 and decrease in irisin levels, along with an early and persistent decrease in IGFBP-3 levels, were observed following the muscle-damaging exercise (p=0.049-0.016). GH, cortisol, prolactin, TSH, follistatin and sclerostin exhibited moderate changes during the recovery period after exercise, though without reaching statistical significance (p>0.05), while correlational analyses revealed significant associationsbetween GH and IGFBP-3, prolactin and sclerostin over time (p=0.049-0.001). The significant hormonal responses observed in this study may indicate their involvement in the regenerative mechanisms following muscle damage, potentially as part of a regulatory network to support a normal adaptation process after muscle-damaging exercise.