Secretion Of Insulin-like Growth Factor Research Articles

Prolyl Hydroxylase Domain Protein 2 Silencing Enhances the Survival and Paracrine Function of Transplanted Adipose-Derived Stem Cells in Infarcted Myocardium

Transplantation of stem cells into damaged hearts has had modest success as a treatment for ischemic heart disease. One of the limitations is the poor stem cell survival in the diseased microenvironment. Prolyl hydroxylase domain protein 2 (PHD2) is a cellular oxygen sensor that regulates 2 key transcription factors involved in cell survival and inflammation: hypoxia-inducible factor and nuclear factor-κB. We studied whether and how PHD2 silencing in human adipose-derived stem cells (ADSCs) enhances their cardioprotective effects after transplantation into infarcted hearts. ADSCs were transduced with lentiviral short hairpin RNA against prolyl hydroxylase domain protein 2 (shPHD2) to silence PHD2. ADSCs, with or without shPHD2, were transplanted after myocardial infarction in mice. ADSCs reduced cardiomyocyte apoptosis, fibrosis, and infarct size and improved cardiac function. shPHD2-ADSCs exerted significantly more protection. PHD2 silencing induced greater ADSC survival, which was abolished by short hairpin RNA against hypoxia-inducible factor-1α. Conditioned medium from shPHD2-ADSCs decreased cardiomyocyte apoptosis. Insulin-like growth factor-1 (IGF-1) levels were significantly higher in the conditioned medium of shPHD2-ADSCs versus ADSCs, and depletion of IGF-1 attenuated the cardioprotective effects of shPHD2-ADSC-conditioned medium. Nuclear factor-κB activation was induced by shPHD2 to induce IGF-1 secretion via binding to IGF-1 gene promoter. PHD2 silencing promotes ADSCs survival in infarcted hearts and enhances their paracrine function to protect cardiomyocytes. The prosurvival effect of shPHD2 on ADSCs is hypoxia-inducible factor-1α dependent, and the enhanced paracrine function of shPHD2-ADSCs is associated with nuclear factor-κB-mediated IGF-1 upregulation. PHD2 silencing in stem cells may be a novel strategy for enhancing the effectiveness of stem cell therapy after myocardial infarction.

Abstract 5083: Dual targeting of the type 1 insulin-like growth factor receptor and its ligands as an effective anti-angiogenic strategy.

Abstract Background. Several childhood sarcomas, exhibit autocrine or paracrine growth through secretion of insulin-like growth factors 1 and 2 (IGF-1, IGF-2) and signaling through the Type 1 receptor (IGF-1R). In some childhood sarcoma xenografts IGF-1R antibodies dramatically decrease VEGF transcription and have potential anti-angiogenic activity. However, tumor-derived IGF-2 results in intrinsic resistance to IGF-1R-targeted antibodies, and continued tumor angiogenesis. We evaluated the anti-angiogenic activity of a ligand-binding antibody (MEDI-573) alone or in combination with IGF-1 receptor-binding antibodies as a potential strategy for effectively suppressing angiogenesis in pediatric sarcomas. Methods. IGF-stimulated signaling was monitored by increased Akt phosphorylation in sarcoma and human vascular endothelial (HUVEC) cells. Effects on angiogenesis were determined in vitro by capillary tube formation in HUVECs and in vivo using a VEGF-stimulated Matrigel assay followed by assay of hemoglobin and CD34 immunostaining. Results. The IGF-ligand binding antibody MEDI-573 suppressed Akt phosphorylation induced by exogenous IGF-1 and IGF-2 in sarcoma cells. Receptor binding antibodies, MAB391 and CP1-B02, suppressed IGF-1-stimulated phosphorylation of Akt, but not that induced by IGF-2. Both receptor-binding antibodies suppressed VEGF-induced HUVEC tube formation in vitro, but this was abrogated by exogenous IGF-2. MEDI-573 inhibited VEGF-stimulated HUVEC proliferation and tube formation in vitro, but did not inhibit angiogenesis in vivo, probably because MEDI-573 binds murine IGF-1 with low affinity. However, in vitro the anti-angiogenic activity of MEDI-573 was also circumvented by human recombinant IGF-1. The combination of receptor-binding and ligand-binding antibodies completely suppressed VEGF-stimulated proliferation of vascular endothelial cells in the presence of IGF-1 and IGF-2, and prevented ligand-induced phosphorylation of IGF-1R/IR receptors. Further, combining receptor-binding and ligand-binding antibodies completely suppressed VEGF-driven angiogenesis in a mouse model where Matrigel plugs containing both IGF-1 and IGF-2 were incorporated with VEGF. Conclusions. Our previous study showed that IGF-2 produced by tumor cells in the microenvironment could circumvent the anti-angiogenic effects of IGF-1 receptor binding antibodies. In contrast, IGF-1 was able to overcome the anti-angiogenic effect of the IGF-ligand binding antibody, MEDI-573. Our current study demonstrates that combining receptor and ligand binding antibodies effectively suppresses VEGF-stimulated angiogenesis in vitro and in a mouse model. Studies are ongoing to evaluate this therapeutic strategy using pediatric sarcoma xenograft models with characterized IGF expression. (Supported by grants CA77776, CA23099 and MedImmune). Citation Format: Hemant K. Bid, Cheryl A. London, Jin Gao, Haihong Zhong, Robert H. Hollingsworth, Peter J. Houghton. Dual targeting of the type 1 insulin-like growth factor receptor and its ligands as an effective anti-angiogenic strategy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5083. doi:10.1158/1538-7445.AM2013-5083

Effect of photoperiod and heat stress in the third trimester of gestation on milk production and circulating hormones in dairy goats

The influence of photoperiod manipulation in the dry period was examined in dairy goats experiencing environmental heat stress. Multiparous Israeli Saanen goats were blocked at dry off (∼60d prepartum) into 2 groups of 4 goats each based on body weight, previous milk production, and detected embryo number. Treatments consisted of long-day (16h light:8h dark) and short-day (8h light:16h dark) photoperiods (LDPP and SDPP, respectively). Heat-stress conditions were applied by manipulating the environment of metabolic rooms to reach a maximum temperature of 37°C between 1000 and 2200h, and a minimum of 23°C and 70.3% relative humidity. All goats were returned to ambient photoperiod after kidding, milked twice daily, and milk yield was automatically recorded. Dry matter intake during the dry period was similar between treatments, averaging 1,114g/d. Milk production was significantly higher in the SDPP than the LDPP group (2,172 vs. 1,550g/d) during the 12-wk experimental period. Milk protein and fat contents were similar in both groups and averaged 3.63 and 4.34%, respectively, whereas milk lactose was higher in the LDPP group (4.77 vs. 4.67%). Heart rates were similar between treatments and averaged 112.6 beats per minute (BPM). Respiration rates were lower in the morning (58.4BPM) compared with the afternoon (91.2BPM) and were not influenced by photoperiod. Rectal temperature was higher for the LDPP than the SDPP group (40.4 vs. 39.6°C). The thyroid hormone level (mean ± SE) was similar in both groups during the dry period, but higher during lactation in the LDPP goats up to 40d postpartum (110±6.59 vs. 156±8.76ng/mL). Plasma IGF-1 (mean ± SE) was higher in the LDPP group (279±62 vs. 162±27ng/mL in SDPP) during the dry period but was similar postkidding, averaging 132±24ng/mL. Plasma prolactin level (mean ± SE) was higher in the LDPP than the SDPP group during the dry period (17.2±1.6 vs. 10.6±0.99ng/mL), whereas it was similar throughout lactation (0.61±0.28ng/mL). These data support the idea that SDPP manipulation during heat load in dry goats can be used as an abatement strategy to reduce the carryover effect of heat stress observed during the subsequent lactation. The higher milk production in SDPP goats is explained by changes in circulating prolactin profile rather than differences in feed intake or secretion of insulin-like growth factor 1.

GTPase ARFRP1 Is Essential for Normal Hepatic Glycogen Storage and Insulin-Like Growth Factor 1 Secretion

The GTPase ADP-ribosylation factor-related protein 1 (ARFRP1) is located at the trans-Golgi compartment and regulates the recruitment of Arf-like 1 (ARL1) and its effector golgin-245 to this compartment. Here, we show that liver-specific knockout of Arfrp1 in the mouse (Arfrp1(liv-/-)) resulted in early growth retardation, which was associated with reduced hepatic insulin-like growth factor 1 (IGF1) secretion. Accordingly, suppression of Arfrp1 in primary hepatocytes resulted in a significant reduction of IGF1 release. However, the hepatic secretion of IGF-binding protein 2 (IGFBP2) was not affected in the absence of ARFRP1. In addition, Arfrp1(liv-/-) mice exhibited decreased glucose transport into the liver, leading to a 50% reduction of glycogen stores as well as a marked retardation of glycogen storage after fasting and refeeding. These abnormalities in glucose metabolism were attributable to reduced protein levels and intracellular retention of the glucose transporter GLUT2 in Arfrp1(liv-/-) livers. As a consequence of impaired glucose uptake into the liver, the expression levels of carbohydrate response element binding protein (ChREBP), a transcription factor regulated by glucose concentration, and its target genes (glucokinase and pyruvate kinase) were markedly reduced. Our data indicate that ARFRP1 in the liver is involved in the regulation of IGF1 secretion and GLUT2 sorting and is thereby essential for normal growth and glycogen storage.

Insulin-like growth factor-1 protects against prion peptide-induced cell death in neuronal cells via inhibition of Bax translocation

Insulin-like growth factor-1 (IGF-1) is one of the most important components of bovine colostrum. It exhibits antiapoptotic and antioxidative activities. Prion diseases are neurodegenerative disorders caused by cell death through mitochondrial dysfunction and increasing generation of reactive oxygen species (ROS). This study examined the protective effect of IGF-1 on residues 106-126 of the cellular prion protein [PrP (106-126)]-mediated mitochondrial neurotoxicity and oxidative stress. In SH-SY5Y human neuronal cells, treatment with PrP (106-126) decreased the cell viability and IGF-1 pretreatment markedly blocked the PrP(106-126)-induced neuronal cell death. IGF-1 inhibited PrP(106-126)-induced intracellular ROS generation and mitochondrial oxidative stress. In addition, IGF-1 blocked the translocation of the Bax protein to the mitochondria induced by PrP (106-126). These results demonstrate that IGF-1 protects neuronal cells against PrP (106-126)-mediated neurotoxicity through an antioxidative effect and blockage of mitochondrial Bax translocation. The results also suggest that regulation of IGF-1 secretion may have a therapeutic potential in the management of mitochondrial dysfunction and oxidative stress-induced neurodegeneration.

Effects of tryptophan supplementation on cashmere fiber characteristics, serum tryptophan, and related hormone concentrations in cashmere goats

This study was designed to investigate the effects of tryptophan (Trp) supplementation on cashmere fiber characteristics and on serum Trp, melatonin (MEL), prolactin (PRL), insulin-like growth factor 1 (IGF-1), triiodothyronine (T3), and thyroxine (T4) concentrations in cashmere goats during the cashmere fast-growth period. Thirty-six Liaoning cashmere wether goats were stratified on the basis of body weight (28 ± 0.8 kg) and assigned randomly to 1 of the following 4 rumen-protected Trp treatments: 0, 2.0, 4.0, and 6.0 g per goat per day. The experimental period lasted 137 d. Blood samples were collected monthly during the daytime (8:00 AM) and at night (8:00 PM). Tryptophan supplementation improved cashmere growth rates, cashmere weight, and body weight (P = 0.001) and increased serum Trp levels, nighttime MEL concentrations, IGF-1, and T3 and T4 concentrations (P < 0.05). Across the treatments and sampling months, a highly positive correlation between cashmere growth rate and nighttime serum MEL concentrations was observed (r = 0.879, P = 0.001). A moderately negative correlation between cashmere growth rates and serum PRL concentrations during the day and at night (rday = –0.645, P = 0.007; rnight = –0.583, P = 0.018) was observed. A moderately positive correlation between the cashmere growth rate and the daytime serum IGF-1 concentration (r = 0.536, P = 0.032) was observed, and no correlation was found between the cashmere growth rate and the other serum hormone concentrations. These data indicate that changes in serum concentrations of MEL, IGF-1, and PRL are related to cashmere growth in Liaoning cashmere goats during the cashmere fast-growth period. Under the experimental conditions of the current trial, we suggest that Trp may promote cashmere growth by increasing daytime IGF-1 and nighttime MEL secretion.

1567 METFORMIN REGULATES THE PROLIFERATION OF PROSTATE EPITHELIAL CELLS INHIBITION OF INSULIN-LIKE GROWTH FACTOR 1 RECEPTOR

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Basic Research1 Apr 20121567 METFORMIN REGULATES THE PROLIFERATION OF PROSTATE EPITHELIAL CELLS INHIBITION OF INSULIN-LIKE GROWTH FACTOR 1 RECEPTOR Xingyuan Xiao, Zongwei Wang, and Aria F. Olumi Xingyuan XiaoXingyuan Xiao Boston, MA More articles by this author , Zongwei WangZongwei Wang Boston, MA More articles by this author , and Aria F. OlumiAria F. Olumi Boston, MA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1339AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Benign prostatic hyperplasia (BPH) is the most common age-related proliferative abnormality of the prostate affecting elderly men throughout the world. Epidemiologic studies suggest that diabetes significantly increases the risk of developing BPH. However, it is unclear whether anti-diabetic medications may be protective against development of BPH. Previously, we have found that stromally expressed insulin-like growth factor 1 (IGF-1) promotes benign prostatic epithelial (BPE) cell proliferation through paracrine mechanisms. Here we demonstrate that Metformin, a first line medication for treatment of type 2 diabetes inhibits the proliferation of BPE cells through affecting the cell cycle and inhibiting the IGF-1R expression. METHODS BPE cell lines BPH-1 and P69, and stromal cell line 3T3 were used. Cellular proliferation and cell cycle analyses were completed by MTS assay and FACS analyses, respectively. The expression of IGF-1 receptor was determined by western-blot and immunocytochemistry. Secretion of IGF-1 in supernatant was measured by ELISA. RESULTS Metformin (0.5-10mM, 6-48h) significantly inhibited the proliferation of BPH-1 and P69 cells in a dose-dependent and time-dependent, but without inducing apoptosis. Treatment with Metformin for 24h lowered the G2/M cell population by 43.24% in P69 cell, and 24.22% in BPH-1 cell. On the other hand, IGF-1 (100ng/ml, 24h) stimulated the cell proliferating (increased by 28.81% in P69 cells and 20.95% in BPH-1 cells) and significantly enhanced the expression of IGF-1R in BPE. Metformin (5mM) abrogated the proliferative effect of IGF-1 on BPE cells. In 3T3 cells, the secretion of IGF-1 was robustly inhibited by Metformin from 574.31pg/ml to 197.61pg/ml. Conditioned medium from 3T3 cells promoted the proliferation and the expression of IGF-1R in BPH-1 and P69 cells. Similarly, Metformin abrogated the ability of 3T3 conditioned medium to promote proliferation of BPE cells. CONCLUSIONS Our study demonstrates that Metformin inhibits the proliferation of BPE cells by suppressing the expression of IGF-1R. Metformin may have a protective role in prostatic proliferation by inhibition of IGF-1R. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e635 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Xingyuan Xiao Boston, MA More articles by this author Zongwei Wang Boston, MA More articles by this author Aria F. Olumi Boston, MA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Pharmacodynamic Modeling of the Effects of Lanreotide Autogel on Growth Hormone and Insulin‐Like Growth Factor 1

Acromegaly arises from excessive levels of growth hormone (GH), many of whose effects are mediated by stimulation of secretion of insulin-like growth factor 1 (IGF-1). Synthetic somatostatin analogues inhibit GH secretion. The objective of the study was to develop a population pharmacodynamic model describing the relationship between serum concentrations of lanreotide (C(P)) and its GH and IGF-1 effects in patients with acromegaly receiving lanreotide Autogel (LA) at doses of 60, 90, or 120 mg by deep subcutaneous route every 28 days. Data were analyzed from 104 patients. The GH and IGF-1 profiles were fit simultaneously using the population approach with NONMEM. The GH vs C(P) and the IGF-1 vs GH relationships were described using inhibitory I(max) and E(max) models, respectively. Results indicated that lanreotide cannot abolish GH completely. C(P) levels of 3.4 ng/mL are required to achieve percentages of hormonal control (GH and IGF-1) of 21% and 36% in not treated and previously treated patients. If the focus is only GH, a C(P) of 3.4 ng/mL corresponds to 33% and 56% controlling rates. Simulations showed that there is a possible clinical benefit if the highest dose of 120 mg LA is administered to patients who are not well controlled by lower doses of LA.

Five-Year Outcomes after Oxandrolone Administration in Severely Burned Children: A Randomized Clinical Trial of Safety and Efficacy

Oxandrolone, an anabolic agent, has been administered for 1 year post burn with beneficial effects in pediatric patients. However, the long-lasting effects of this treatment have not been studied. This single-center prospective trial determined the long-term effects of 1 year of oxandrolone administration in severely burned children; assessments were continued for up to 4 years post therapy. Patients 0 to 18 years old with burns covering >30% of the total body surface area were randomized to receive placebo (n = 152) or oxandrolone, 0.1 mg/kg twice daily for 12 months (n = 70). At hospital discharge, patients were randomized to a 12-week exercise program or to standard of care. Resting energy expenditure, standing height, weight, lean body mass, muscle strength, bone mineral content (BMC), cardiac work, rate pressure product, sexual maturation, and concentrations of serum inflammatory cytokines, hormones, and liver enzymes were monitored. Oxandrolone substantially decreased resting energy expenditure and rate pressure product, increased insulin-like growth factor-1 secretion during the first year after burn injury, and, in combination with exercise, increased lean body mass and muscle strength considerably. Oxandrolone-treated children exhibited improved height percentile and BMC content compared with controls. The maximal effect of oxandrolone was found in children aged 7 to 18 years. No deleterious side effects were attributed to long-term administration. Administration of oxandrolone improves long-term recovery of severely burned children in height, BMC, cardiac work, and muscle strength; the increase in BMC is likely to occur by means of insulin-like growth factor-1. These benefits persist for up to 5 years post burn.

Serum response factor regulates bone formation via IGF-1 and Runx2 signals

Serum response factor (SRF) plays vital roles in numerous cellular processes; however, the physiological function of SRF in skeletal tissue remains unknown. In several organ systems, SRF regulates the expression of insulin-like growth factor-1 (IGF-1), which is crucial for normal development of mineralized skeleton and bone remodeling throughout life. Here, we show that conditional deletion of SRF in osteoblasts by osteocalcin-Cre generated viable mice with normal body size and body weight. Compared with normal siblings, osteoblast-specific SRF-deficient adult mice exhibited a marked decrease in bone mineral density and bone formation rate. Deletion of SRF in primary mouse calvarial osteoblasts reduced cell differentiation and mineralization in vitro. This was accompanied by a decrease in IGF-1 expression and secretion. Addition of IGF-1 in the culture media enhanced osteoblast differentiation in control cells and partially restored the mineralization defect of SRF-deficient cells, supporting an important role of SRF in regulating IGF-1 and IGF-1-mediated osteoblast differentiation. IGF-1-induced Akt activation was inhibited in SRF-deficient calvarial cells and enhanced in the SRF overexpressed cells. In addition, SRF deficiency decreased the transcriptional activity of Runx2, the key transcription factor for osteogenesis. Overexpression of SRF induced Runx2 transactivity in control cells and restored Runx2 transactivity in the SRF-deficient cells. Taken together, we conclude that SRF is important for IGF-1-induced osteoblast differentiation and mineralization via regulating IGF-1 expression and Runx2 transactivity.

Forskolin Enhances In Vivo Bone Formation by Human Mesenchymal Stromal Cells

Activation of the protein kinase A (PKA) pathway with dibutyryl cyclic adenosine monophosphate (db-cAMP) was recently shown to enhance osteogenic differentiation of human mesenchymal stromal cells (hMSCs) in vitro and bone formation in vivo. The major drawback of this compound is its inhibitory effect on proliferation of hMSCs. Therefore, we investigated whether fine-tuning of the dose and timing of PKA activation could enhance bone formation even further, with minimum effects on proliferation. To test this, we selected two different PKA activators (8-bromo-cAMP (8-br-cAMP) and forskolin) and compared their effects on proliferation and osteogenic differentiation with those of db-cAMP. We found that all three compounds induced alkaline phosphatase levels, bone-specific target genes, and secretion of insulin-like growth factor-1, although 8-br-cAMP induced adipogenic differentiation in long-term cultures and was thus considered unsuitable for further in vivo testing. All three compounds inhibited proliferation of hMSCs in a dose-dependent manner, with forskolin inhibiting proliferation most. The effect of forskolin on in vivo bone formation was tested by pretreating hMSCs before implantation, and we observed greater amounts of bone using forskolin than db-cAMP. Our data show forskolin to be a novel agent that can be used to increase bone formation and also suggests a role for PKA in the delicate balance between adipogenic and osteogenic differentiation.

Activity of the neuroendocrine axes in patients with polymyalgia rheumatica before and after TNF-α blocking etanercept treatment

IntroductionIn this study, we evaluated the activity of the neuroendocrine axes in patients with polymyalgia rheumatica (PMR) before and after tumor necrosis factor (TNF)-α-blocking etanercept treatment, which previously has been shown to reduce interleukin 6 (IL-6) and C-reactive protein (CRP) markedly in PMR.MethodsPlasma samples were collected from 10 glucocorticoid-naïve patients with PMR and 10 matched controls before and after etanercept treatment (25 mg biweekly for 2 weeks). The primary end points were pre- and posttreatment levels of adrenocorticotropic hormone (ACTH), cortisol, adrenaline, thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), prolactin, and insulin-like growth factor 1 (IGF-1).ResultsBefore TNF-α-blocking treatment, plasma TNF-α, ACTH, and cortisol levels were higher in patients versus controls (P < 0.05 and P < 0.001, respectively); during TNF-α blockade in patients, levels of both hormones decreased (P < 0.05 and P < 0.01, respectively), whereas levels in controls increased (P < 0.05), abolishing the pretreatment differences. Pretreatment adrenaline levels were more than twice as high in patients than in controls (P < 0.01); after treatment in patients, levels had decreased (P < 0.05) but remained higher versus controls (P < 0.05). Levels of the other hormones never differed significantly between groups (P > 0.05).ConclusionsIn PMR, TNF-α may increase the activities of the hypothalamic-pituitary-adrenal and the hypothalamic-sympthoadrenomedullary axes. Secretion of TSH, FSH, prolactin, and IGF-1 is not clearly changed in PMR.Trial registrationClinicalTrials.gov (NCT00524381).

An approach to constitutional delay of growth and puberty

Constitutional delay of growth and puberty is a transient state of hypogonadotropic hypogonadism associated with prolongation of childhood phase of growth, delayed skeletal maturation, delayed and attenuated pubertal growth spurt, and relatively low insulin-like growth factor-1 secretion. In a considerable number of cases, the final adult height (Ht) does not reach the mid-parental or the predicted adult Ht for the individual, with some degree of disproportionately short trunk. In the pre-pubertal male, testosterone (T) replacement therapy can be used to induce pubertal development, accelerate growth and relieve the psychosocial complaints of the adolescents. However, some issues in the management are still unresolved. These include type, optimal timing, dose and duration of sex steroid treatment and the possible use of adjunctive or alternate therapy including: oxandrolone, aromatase inhibitors and human growth hormone.

Large Tumor of the Liver and Hypoglycemic Shock in an 85-Year-Old Patient

Question: An 85-year-old woman was referred to our institution with a palpable mass in the upper abdomen. Her past medical history was unremarkable except for arterial hypertension and coronary artery disease. Lately, she had experienced frequent episodes of drenching sweats. On physical examination, a large mass was palpated in the upper abdomen. Computed tomography showed a large, heterogenous liver tumor of the left lobe measuring 17 cm in diameter (Figure A) . The liver showed no signs of cirrhosis and no other lesions or pathologic findings were observed in the abdomen or the thorax. Before undergoing surgery the patient had to be treated in the intensive care unit for hypoglycemic shock (lowest blood glucose level, 32 mg/dL). Laparotomy showed an extensive, lobulated liver tumor of the left lobe with a pseudocapsule. Left hemihepatectomy was performed and the tumor was removed intact. What is your diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Macroscopically, the tumor showed a nodular, firm, grey-white mass on the cut surface. Histologic evaluation revealed a spindle cell tumor with immunohistochemically strong staining for CD34 and bcl-2 and a negative staining against cytokeratin, c-Kit (CD117), DOG-1, S-100, smooth muscle, actin and desmin (Figure B, C). Only rare mitotic figures were present (3/50 high-power field) with 5% Ki-67 reactivity. Molecular pathology testing demonstrated wild-type for c-kit gene and PDGF-receptor A gene. A diagnosis of solitary fibrous tumor (SFT) of the liver was made. The postoperative clinical course of the patient was uneventful. After successful surgery with complete resection of the tumor mass, no further attacks of hypoglycemia occurred. Because SFT was not suspected at first in this patient, insulin-like growth factor was not measured before surgery. SFT is a rare neoplasm that most frequently affects the pleura, but can also be found in many extrapleural sites. SFT of the liver is a very rare pathologic entity, predominantly affecting females and typically presenting in middle age in a noncirrhotic liver. To date, <40 cases of SFT of the liver have been reported.1Changku J. Shaohua S. Zhicheng Z. et al.Solitary fibrous tumor of the liver: retrospective study of reported cases.Cancer Invest. 2006; 24: 132-135Crossref PubMed Scopus (31) Google Scholar Most likely, SFT are histogenetically related to a CD34-positive fibroblastic stem cell. SFT of the liver is usually found as a giant tumor causing nonspecific symptoms of pressure, upper abdominal pain, or abdominal distension. About 5% of the patients present with hypoglycemia owing to secretion of insulin-like growth factors by the tumor.2Fama F. Le Bouc Y. Barrande G. et al.Solitary fibrous tumour of the liver with IGF-II-related hypoglycaemia A case report.Langenbecks Arch Surg. 2008; 393: 611-616Crossref PubMed Scopus (26) Google Scholar, 3Guglielmi A. Frameglia M. Iuzzolino P. et al.Solitary fibrous tumor of the liver with CD 34 positivity and hypoglycemia.J Hepatobiliary Pancreat Surg. 1998; 5: 212-216Crossref PubMed Scopus (42) Google Scholar Differential diagnosis includes other benign or malignant hepatic tumors, such as sarcoma, leiomyoma, and gastrointestinal stroma tumor. It is difficult to distinguish this tumor from other spindle cell neoplasms without immunohistochemical examinations and a combination of markers is needed for differential diagnosis (CD34, bcl-2). SFT of the liver is a rare neoplasm with distinct histopathologic and immunohistochemical features and varied clinical manifestations.

IGF-1 Induction by Acylated Steryl β-Glucosides Found in a Pre-Germinated Brown Rice Diet Reduces Oxidative Stress in Streptozotocin-Induced Diabetes

BackgroundThe pathology of diabetic neuropathy involves oxidative stress on pancreatic β-cells, and is related to decreased levels of Insulin-like growth factor 1 (IGF-1). Acylated steryl β-glucoside (PR-ASG) found in pre-germiated brown rice is a bioactive substance exhibiting properties that enhance activity of homocysteine-thiolactonase (HTase), reducing oxidative stress in diabetic neuropathy. The biological importance of PR-ASG in pancreatic β-cells remains unknown.Here we examined the effects of PR-ASG on IGF-1 and glucose metabolism in β-cells exposed to oxidative stress.Methodology/Principal FindingsIn the present study, a pre-germinated brown rice (PR)-diet was tested in streptozotocin (STZ)-induced diabetic rats. Compared with diabetic rats fed control diets, the PR-diet fed rats showed an improvement of serum metabolic and neurophysiological parameters. In addition, IGF-1 levels were found to be increased in the serum, liver, and pancreas of diabetic rats fed the PR-diet. The increased IGF-1 level in the pancreas led us to hypothesize that PR-ASG is protective for islet β-cells against the extensive injury of advanced or severe diabetes. Thus we examined PR-ASG to determine whether it showed anti-apoptotic, pro-proliferative effects on the insulin-secreting β-cells line, INS-1; and additionally, whether PR-ASG stimulated IGF-1 autocrine secretion/IGF-1-dependent glucose metabolism. We have demonstrated for the first time that PR-ASG increases IGF-1 production and secretion from pancreatic β-cells.Conclusion/SignificanceThese findings suggest that PR-ASG may affect pancreatic β-cells through the activation of an IGF-1-dependent mechanism in the diabetic condition. Thus, intake of pre-germinated brown rice may have a beneficial effect in the treatment of diabetes, in particular diabetic neuropathy.

Locally produced insulin-like growth factor-1 by orbital fibroblasts as implicative pathogenic factor rather than systemically circulated IGF-1 for patients with thyroid-associated ophthalmopathy

To determine the correlation between clinical activity scores (CAS) of thyroid-associated ophthalmology (TAO) patients and their locally produced and/or systemically circulating insulin-like growth factor-1 (IGF-1), and to assess the possible pathogenic role of IGF-1 in TAO. Eighteen patients with TAO, and 16 age- and gender-matched controls were included in the present study. Among them, orbital tissue surgically collected from five TAO patients and five healthy controls was used for orbital fibroblasts (OFs) culture and in vitro study. Total and free IGF-1 in serum levels were determined by an ELISA kit for all the participants in this study. The IGF-1 concentration in culture media of OFs was determined using a noncompetitive time-resolved radioimmunoassay kit. The effect of octreotide (OCT), a somatostatin analog, on proliferation of OFs was assessed using the MTT assay. IGF-1 mRNA levels were measured by real-time polymerase chain reaction (PCR). Cultured OFs from both TAO patients and normal donors secreted IGF-1, and the secretion continued over a 72 hour period in vitro. IGF-1 secretion by OFs was elevated in the TAO group. Both the elevated secretion of IGF-1 and proliferation of OFs from TAO patients could be inhibited by OCT. Result of quantitative PCR showed that IGF-1 mRNA expression by OFs in TAO patients was up-regulated more than 2-fold compared with normal controls (P < 0.05), and this up-regulation was prevented by OCT treatment. Total and free serum IGF-1 levels in TAO patients were similar to those of normal controls. However, the IGF-1 level in cultured medium of OFs from TAO patients, but not serum levels of IGF-1, was positively correlated with CAS (r = 0.97, P = 0.017). Local production of IGF-1 by cultured OFs may be positively correlated with CAS, whereas systemically circulating IGF-1 may remain unchanged in TAO patients. Thus, locally produced IGF-1 may develop a role in the pathogenesis of TAO in an autocrine or paracrine fashion. The inhibitory effect of OCT on proliferating and IGF-1 mRNA levels of cultured OFs from TAO patients may be used as the mechanistic explanation for somatostatin analog as a valuable option in the treatment of TAO.

Novel View on Stem Cell Compartment and Aging - a Number of Pluripotent Very Small Embryonic Like Stem Cells and Hematopoietic Stem Cells in Murine Bone Marrow Is High in Several Long-Living and Reduced in Short-Living Murine Strains and Unexpectedly Inversely Correlates in These Animals with Plasma Growth Hormone/Insulin-Like Growth Factor-1 Level

Abstract LBA-5 Background:It is known that an increase in caloric intake leads to increase in plasma growth hormone (GH) level that subsequently induces secretion of insulin-like growth factor-1 (IGF-1) from liver, what leads to accelerated aging (Nature 2010;464:504). On the other hand, caloric restriction and a resulting decrease in plasma IGF-1 level has the opposite effect and extends lifespan. It also known that adult tissues contain a population of pluripotent very small embryonic like stem cells (VSELs) that play as postulated an important role in rejuvenation of long term hematopoietic stem cells (LT-HSCs) in bone marrow (BM) Leukemia 2011; doi:10.1038/leu.2011.73, Exp. Hematology 2011;39:225–237). As we observed previously, the number of these cells in murine BM decreases with age and VSELs are kept quiescent in BM and protected from premature depletion by erasure of the somatic imprint in differentially methylated regions (DMRs) of some paternally imprinted genes involved in insulin/insulin growth factors signaling (IIS) such as e.g., Igf2-H19 and RasGRF1 (Leukemia 2009;23:2042). Hypothesis:To explain and connect these phenomena together, we hypothesized that prolonged insulin/insulin growth factors signaling (IIS) prematurely depletes VSELs from the adult tissues and in BM may negatively impact on population of HSCs. Material and Methods:The number of VSELs and HSCs in long living murine strains with inborn low level of circulating IGF-1 (Laron- and Ames- dwarfs) as well as in short living mice with high levels of circulating IGF-1 (e.g., transgenic mice that overexpress bovine growth hormone; bGH) was evaluated by FACS. VSELs were isolated and epigenetic status of genes regulating pluripotency (e.g., Oct-4) as well as imprinted genes regulating IIS was evaluated by employing bisulfate modification of DNA followed by sequencing and by COBRE assay. We also challenged long living mice with low IGF-1 plasma level by daily injections of recombinant GH or IGF-1. Results:We found that the number of VSELs and HSCs residing in BM inversely correlates with plasma GH/IGF-1 level. To support this, mice with low circulating plasma IGF-1 levels (Laron- and Ames-dwarf mice) have higher numbers of VSELs and HSCs in BM that, in contrast to aged-matched normal littermates, are maintained at high levels even into advanced age. The analysis of molecular signature of VSELs in these animals revealed prolonged retention of hypomethylation in the DMRs within the Igf2-H19 and RasGRF1 loci, which attenuates IIS signaling in these cells. The number of VSELs, however, decreased in these animals after prolonged treatment with GH or recombinant IGF-I. Conversely, mice with elevated IGF-I level in plasma due to expression of the GH transgene or normal wild type mice injected for a sustained period with recombinant GH both exhibit significant decreases in the number of VSELs and HSCs in BM compared to control animals. These decreases were paralleled by epigenetic changes in Igf2-H19 and RasGRF1 loci in which DMRs became hypermethylated over time. These changes in methylation lead to increases in IGF-2 and RasGRF1 expression and may explain why GH transgenic mice have an increase in IIS that leads to shortening of life span in these animals. Conclusions:Our data shed new light on the relationships between senescence, GH/IGF-1 level, prolonged IIS, and number of VSELs and LT-HSCs. Accordingly, we propose a new paradigm in which a decrease in IIS (e.g., due to caloric restriction that lowers plasma IGF-1 level) may delay the age-dependent elimination of VSELs from adult tissues. By contrast, chronic IIS (e.g., due to chronic high caloric intake and the resulting elevated GH and IGF-1 levels) prematurely depletes VSELs residing in adult organs, which for example in BM leads to a decrease in the number of LT-HSCs. This study also indicates that GH-based anti-aging therapies need careful re-evaluation of their potentially uncontrolled stimulation of VSELs in BM that may lead to development of hematological malignancies. In support of this, elevated GH and IIS lead to hematological malignancies, while, by contrast, Laron dwarf mice and Laron dwarf patients, which have a low plasma IGF-1 levels, do not develop leukemias. Disclosures:Ratajczak:Neostem Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Novel View on Stem Cell Compartment and Aging - a Number of Pluripotent Very Small Embryonic Like Stem Cells and Hematopoietic Stem Cells in Murine Bone Marrow Is High in Several Long-Living and Reduced in Short-Living Murine Strains and Unexpectedly Inversely Correlates in These Animals with Plasma Growth Hormone/Insulin-Like Growth Factor-1 Level

Abstract LBA-5 Background: It is known that an increase in caloric intake leads to increase in plasma growth hormone (GH) level that subsequently induces secretion of insulin-like growth factor-1 (IGF-1) from liver, what leads to accelerated aging (Nature 2010;464:504). On the other hand, caloric restriction and a resulting decrease in plasma IGF-1 level has the opposite effect and extends lifespan. It also known that adult tissues contain a population of pluripotent very small embryonic like stem cells (VSELs) that play as postulated an important role in rejuvenation of long term hematopoietic stem cells (LT-HSCs) in bone marrow (BM) Leukemia 2011; doi:10.1038/leu.2011.73, Exp. Hematology 2011;39:225–237). As we observed previously, the number of these cells in murine BM decreases with age and VSELs are kept quiescent in BM and protected from premature depletion by erasure of the somatic imprint in differentially methylated regions (DMRs) of some paternally imprinted genes involved in insulin/insulin growth factors signaling (IIS) such as e.g., Igf2-H19 and RasGRF1 (Leukemia 2009;23:2042). Hypothesis: To explain and connect these phenomena together, we hypothesized that prolonged insulin/insulin growth factors signaling (IIS) prematurely depletes VSELs from the adult tissues and in BM may negatively impact on population of HSCs. Material and Methods: The number of VSELs and HSCs in long living murine strains with inborn low level of circulating IGF-1 (Laron- and Ames- dwarfs) as well as in short living mice with high levels of circulating IGF-1 (e.g., transgenic mice that overexpress bovine growth hormone; bGH) was evaluated by FACS. VSELs were isolated and epigenetic status of genes regulating pluripotency (e.g., Oct-4) as well as imprinted genes regulating IIS was evaluated by employing bisulfate modification of DNA followed by sequencing and by COBRE assay. We also challenged long living mice with low IGF-1 plasma level by daily injections of recombinant GH or IGF-1. Results: We found that the number of VSELs and HSCs residing in BM inversely correlates with plasma GH/IGF-1 level. To support this, mice with low circulating plasma IGF-1 levels (Laron- and Ames-dwarf mice) have higher numbers of VSELs and HSCs in BM that, in contrast to aged-matched normal littermates, are maintained at high levels even into advanced age. The analysis of molecular signature of VSELs in these animals revealed prolonged retention of hypomethylation in the DMRs within the Igf2-H19 and RasGRF1 loci, which attenuates IIS signaling in these cells. The number of VSELs, however, decreased in these animals after prolonged treatment with GH or recombinant IGF-I. Conversely, mice with elevated IGF-I level in plasma due to expression of the GH transgene or normal wild type mice injected for a sustained period with recombinant GH both exhibit significant decreases in the number of VSELs and HSCs in BM compared to control animals. These decreases were paralleled by epigenetic changes in Igf2-H19 and RasGRF1 loci in which DMRs became hypermethylated over time. These changes in methylation lead to increases in IGF-2 and RasGRF1 expression and may explain why GH transgenic mice have an increase in IIS that leads to shortening of life span in these animals. Conclusions: Our data shed new light on the relationships between senescence, GH/IGF-1 level, prolonged IIS, and number of VSELs and LT-HSCs. Accordingly, we propose a new paradigm in which a decrease in IIS (e.g., due to caloric restriction that lowers plasma IGF-1 level) may delay the age-dependent elimination of VSELs from adult tissues. By contrast, chronic IIS (e.g., due to chronic high caloric intake and the resulting elevated GH and IGF-1 levels) prematurely depletes VSELs residing in adult organs, which for example in BM leads to a decrease in the number of LT-HSCs. This study also indicates that GH-based anti-aging therapies need careful re-evaluation of their potentially uncontrolled stimulation of VSELs in BM that may lead to development of hematological malignancies. In support of this, elevated GH and IIS lead to hematological malignancies, while, by contrast, Laron dwarf mice and Laron dwarf patients, which have a low plasma IGF-1 levels, do not develop leukemias. Disclosures: Ratajczak: Neostem Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Primitive Stem Cells Derived from Bone Marrow Express Glial and Neuronal Markers and Support Revascularization in Injured Retina Exposed to Ischemic and Mechanical Damage

Ischemic or mechanical injury to the optic nerve is an irreversible cause of vision loss, associated with limited regeneration and poor response to neuroprotective agents. The aim of this study was to assess the capacity of adult bone marrow cells to participate in retinal regeneration following the induction of anterior ischemic optic neuropathy (AION) and optic nerve crush (ONC) in a rodent model. The small-sized subset of cells isolated by elutriation and lineage depletion (Fr25lin(-)) was found to be negative for the neuroglial markers nestin and glial fibrillary acidic protein (GFAP). Syngeneic donor cells, identified by genomic marker in sex-mismatched transplants and green fluorescent protein, incorporated into the injured retina (AION and ONC) at a frequency of 0.35%-0.45% after intravenous infusion and 1.8%-2% after intravitreous implantation. Perivascular cells with astrocytic morphology expressing GFAP and vimentin were of the predominant lineage that engrafted after AION injury; 10%-18% of the donor cells incorporated in the retinal ganglion cell layer and expressed NeuN, Thy-1, neurofilament, and beta-tubulin III. The Fr25lin(-) cells displayed an excellent capacity to migrate to sites of tissue disruption and developed coordinated site-specific morphological and phenotypic neural and glial markers. In addition to cellular reconstitution of the injured retinal layers, these cells contributed to endothelial revascularization and apparently supported remodeling by secretion of insulin-like growth factor-1. These results suggest that elutriated autologous adult bone marrow-derived stem cells may serve as an accessible source for cellular reconstitution of the retina following injury.

Magnesium and anabolic hormones in older men

Optimal nutritional and hormonal statuses are determinants of successful ageing. The age associated decline in anabolic hormones such as testosterone and insulin-like growth factor 1 (IGF-1) is a strong predictor of metabolic syndrome, diabetes and mortality in older men. Studies have shown that magnesium intake affects the secretion of total IGF-1 and increase testosterone bioactivity. This observation suggests that magnesium can be a modulator of the anabolic/catabolic equilibrium disrupted in the elderly people. However, the relationship between magnesium and anabolic hormones in men has not been investigated. We evaluated 399 ≥65-year-old men of CHIANTI in a study population representative of two municipalities of Tuscany (Italy) with complete data on testosterone, total IGF-1, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS) and serum magnesium levels. Linear regression models were used to test the relationship between magnesium and testosterone and IGF-1. Mean age of the population was 74.18 ± 6.43 (years ± SD, age range 65.2-92.4). After adjusting for age, magnesium was positively associated with total testosterone (β ± SE, 34.9 ± 10.3; p = 0.001) and with total IGF-1 (β ± SE, 15.9 ± 4.8; p = 0.001). After further adjustment for body mass index (BMI), log (IL-6), log (DHEAS), log (SHBG), log (insulin), total IGF-1, grip strength, Parkinson's disease and chronic heart failure, the relationship between magnesium and total testosterone remained strong and highly significant (β ± SE, 48.72 ± 12.61; p = 0.001). In the multivariate analysis adjusted for age, BMI, log (IL-6), liver function, energy intake, log (insulin), log (DHEAS), selenium, magnesium levels were also still significantly associated with IGF-1 (β ± SE, 16.43 ± 4.90; p = 0.001) and remained significant after adjusting for total testosterone (β ± SE, 14.4 ± 4.9; p = 0.01). In a cohort of older men, magnesium levels are strongly and independently associated with the anabolic hormones testosterone and IGF-1.