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Sample records for igf-1 induced human

  1. Diosgenin induces apoptosis in IGF-1-stimulated human thyrocytes through two caspase-dependent pathways

    SciTech Connect

    Mu, Shumin; Tian, Xingsong; Ruan, Yongwei; Liu, Yuantao; Bian, Dezhi; Ma, Chunyan; Yu, Chunxiao; Feng, Mei; Wang, Furong; Gao, Ling; Zhao, Jia-jun

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Diosgenin induces apoptosis in IGF-1-treated thyrocytes through two caspase pathways. Black-Right-Pointing-Pointer Diosgenin inhibits FLIP and activates caspase-8 in FAS related-pathway. Black-Right-Pointing-Pointer Diosgenin increases ROS, regulates the ratio of Bax/Bcl-2 in mitochondrial pathway. -- Abstract: Insulin-like growth factor-1 (IGF-1) is a growth factor of the thyroid that has been shown in our previous study to possess proliferative and antiapoptotic effects in FRTL-5 cell lines through the upregulation of cyclin D and Fas-associated death domain-like interleukin-1-converting enzyme (FLICE)-inhibitory protein (FLIP). Diosgenin, a natural steroid sapogenin from plants, has been shown to induce apoptosis in many cell lines, with the exception of thyroid cells. In this report, we investigated the apoptotic effect and mechanism of diosgenin in IGF-1-stimulated primary human thyrocytes. Primary human thyrocytes were preincubated with or without IGF-1 for 24 h and subsequently exposed to varying concentrations of diosgenin for different times. We found that diosgenin induced apoptosis in human thyrocytes pretreated with IGF-1 in a dose-dependent manner through the activation of caspase cascades. Moreover, diosgenin inhibited FLIP and activated caspase-8 in the FAS-related apoptotic pathway. Diosgenin increased the production of ROS, regulated the balance of Bax and Bcl-2 and cleaved caspase-9 in the mitochondrial apoptotic pathway. These results indicate that diosgenin induces apoptosis in IGF-1-stimulated primary human thyrocytes through two caspase-dependent pathways.

  2. Improving expression of recombinant human IGF-1 using IGF-1R knockout CHO cell lines.

    PubMed

    Romand, Sandrine; Jostock, Thomas; Fornaro, Mara; Schmidt, Joerg; Ritter, Anett; Wilms, Burkhard; Laux, Holger

    2016-05-01

    Chinese Hamster Ovary (CHO) cells are widely used for the large-scale production of recombinant biopharmaceuticals. However, attempts to express IGF-1 (a mutated human Insulin-like growth factor 1 Ea peptide (hIGF-1Ea mut)) in CHO cells resulted in poor cell growth and low productivity (0.1-0.2 g/L). Human IGF-1 variants negatively impacted CHO cell growth via the IGF-1 receptor (IGF-1R). Therefore knockout (KO) of the IGF-1R gene in two different CHO cell lines as well as knockdown (KD) of IGF-1R in one CHO cell line were performed. These cell line engineering approaches decreased significantly the hIGF-1 mediated cell growth inhibition and increased productivity of both KO CHO cell lines as well as of the KD CHO cell line. A productivity increase of 10-fold at pool level and sevenfold at clone level was achieved, resulting in a titer of 1.3 g/L. This data illustrate that cell line engineering approaches are powerful tools to improve the yields of recombinant proteins which are difficult to produce in CHO cells.

  3. Lipid raft-regulated IGF-1R activation antagonizes TRAIL-induced apoptosis in gastric cancer cells.

    PubMed

    Xu, Ling; Qu, Xiujuan; Hu, Xuejun; Zhu, Zhitu; Li, Ce; Li, Enze; Ma, Yanju; Song, Na; Liu, Yunpeng

    2013-11-29

    Gastric cancer cells are resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and the resistance mechanism is not fully understood. In human gastric cancer MGC803 and BGC823 cells, TRAIL induces insulin-like growth factor-1 receptor (IGF-1R) pathway activation. Treatment with IGF-1R inhibitor OSI-906 or small interfering RNAs against IGF-1R, prevents IGF-1R pathway activation and increases TRAIL-induced apoptosis. The TRAIL-induced IGF-1R pathway activation is promoted by IGF-1R translocation into lipid rafts. Moreover, the translocation of IGF-1R into lipid rafts is regulated by Casitas B-lineage lymphoma b (Cbl-b). Taken together, TRAIL-induced IGF-1R activation antagonizes TRAIL-induced apoptosis by Cbl-b-regulated distribution of IGF-1R in lipid rafts.

  4. Interference of silibinin with IGF-1R signalling pathways protects human epidermoid carcinoma A431 cells from UVB-induced apoptosis

    SciTech Connect

    Liu, Weiwei; Otkur, Wuxiyar; Li, Lingzhi; Wang, Qiong; He, Hao; Zang, Linghe; Hayashi, Toshihiko; Tashiro, Shin-ichi; Onodera, Satoshi; Xia, Mingyu; Ikejima, Takashi

    2013-03-08

    Highlights: ► Silibinin protects A431 cells from UVB irradiation-induced apoptosis. ► Up-regulation of the IGF-1R-JNK/ERK pathways by UVB induces cell apoptosis. ► Silibinin inhibits IGF-1R pathways to repress caspase-8-mediated apoptosis. -- Abstract: Ultraviolet B (UVB) from sunlight is a major cause of cutaneous lesion. Silibinin, a traditional hepatic protectant, elicits protective effects against UVB-induced cellular damage. In A431 cells, the insulin-like growth factor-1 receptor (IGF-1R) was markedly up-regulated by UVB irradiation. The activation of the IGF-1R signalling pathways contributed to apoptosis of the cells rather than rescuing the cells from death. Up-regulated IGF-1R stimulated downstream mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinases (JNK) and extracellular signal-regulated protein kinases 1/2 (ERK1/2). The subsequent activation of caspase-8 and caspase-3 led to apoptosis. The activation of IGF-1R signalling pathways is the cause of A431 cell death. The pharmacological inhibitors and the small interfering RNA (siRNA) targeting IGF-1R suppressed the downstream activation of JNK/ERK-caspases to help the survival of the UVB-irradiated A431 cells. Indeed, silibinin treatment suppressed the IGF-1R-JNK/ERK pathways and thus protected the cells from UVB-induced apoptosis.

  5. Intranasal Human Growth Hormone (hGH) Induces IGF-1 Levels Comparable With Subcutaneous Injection With Lower Systemic Exposure to hGH in Healthy Volunteers

    PubMed Central

    Lewis, Andrew L.; Patel, Tina; Jeffery, Kirk; King, Gareth; Savage, Martin; Shalet, Stephen; Illum, Lisbeth

    2015-01-01

    Context: The development of an improved, efficacious human GH (hGH) product administered by a noninjectable route of delivery such as the nasal route is highly desirable. We have developed a novel nasal hGH product (CP024) that showed excellent nasal absorption in animal models; however, the translation of these results into the clinical setting is essential because past attempts to develop such formulations by other groups have been unable to induce IGF-1 in man. Objective: The objective of the study was to assess the pharmacokinetics, pharmacodynamics, and tolerability of CP024 compared with a sc hGH injection. Design: This was a single-center, nonrandomized placebo-controlled, open-label, five-way crossover study in eight healthy volunteers. Setting: The study was carried out at a contract research organization, Quotient Bioresearch. Volunteers: Eight healthy male volunteers, given an iv infusion of octreotide to suppress the endogenous GH secretion during the study period, participated in the study. No volunteers were withdrawn due to side effects. Main Outcome Measures: Measurement of hGH and IGF-1 levels and tolerability of the drug product was performed. Results: No serious adverse events were reported and no subjects withdrawn from study due to the treatment. After the nasal administration of CP024, 3-fold higher hGH blood levels were obtained as compared with hGH nasal control. The relative bioavailability was about 3%. CP024 (given twice daily) induced a significant increase in IGF-1 levels up to 19 hours after administration, with no significant difference to those obtained after the sc injection of hGH. Conclusions: The study indicates that CP024 is a promising candidate for an efficacious nasal product for the treatment of GH deficiency due to induction of IGF-1 similar to that after a sc injection, despite the lower plasma hGH concentration obtained. A dose-response study is needed to evaluate the optimal nasal dose. PMID:26425883

  6. IGF-1R modulation of acute GH-induced STAT5 signaling: role of protein tyrosine phosphatase activity.

    PubMed

    Gan, Yujun; Zhang, Yue; Buckels, Ashiya; Paterson, Andrew J; Jiang, Jing; Clemens, Thomas L; Zhang, Zhong-Yin; Du, Keyong; Chang, Yingzi; Frank, Stuart J

    2013-11-01

    GH is a potent anabolic and metabolic factor that binds its cell surface receptor (GHR), activating the GHR-associated tyrosine kinase, Janus kinase 2, which phosphorylates and activates the latent transcription factor, signal transducer and activator of transcription 5 (STAT5). Some GH actions are mediated by the elaboration of IGF-1, which exerts effects by binding and activating the heterotetrameric tyrosine kinase growth factor receptor, IGF-1R. In addition to this GH-GHR-IGF-1-IGF-1R scheme, we have demonstrated in primary osteoblasts and in islet β-cells that then deletion or silencing of IGF-1R results in diminished GH-induced STAT5 phosphorylation, suggesting that the presence of IGF-1R may facilitate GH signaling. In this study, we explore potential roles for protein tyrosine phosphatase activity in modulating GH-induced signaling, comparing conditions in which IGF-1R is present or diminished. We confirm that in mouse primary osteoblasts harboring loxP sites flanking the IGF-1R gene, infection with an adenovirus that expresses the Cre recombinase results in IGF-1R deletion and diminished acute GH-induced STAT5 phosphorylation. Furthermore, we present a new model of IGF-1R silencing, in which expression of short hairpin RNA directed at IGF-1R greatly reduces IGF-1R abundance in LNCaP human prostate cancer cells. In both models, treatment with a chemical inhibitor of protein tyrosine phosphatase-1B (PTP-1B), but not one of src homology region 2 domain-containing phosphotase-1 (SHP-1) and SHP-2, reverses the loss of GH-induced STAT5 phosphorylation in cells lacking IGF-1R but has no effect in cells with intact IGF-1R. Furthermore, expression of either a dominant-negative PTP-1B or the PTP-1B-interacting inhibitory protein, constitutive photomorphogenesis 1, also rescues acute GH-induced STAT5 signaling in IGF-1R-deficient cells but has no effect in IGF-1R replete cells. By expressing a substrate-trapping mutant PTP-1B, we demonstrate that tyrosine

  7. Involvement of phosphoinositide 3-kinase in insulin- or IGF-1-induced membrane ruffling.

    PubMed Central

    Kotani, K; Yonezawa, K; Hara, K; Ueda, H; Kitamura, Y; Sakaue, H; Ando, A; Chavanieu, A; Calas, B; Grigorescu, F

    1994-01-01

    Insulin, IGF-1 or EGF induce membrane ruffling through their respective tyrosine kinase receptors. To elucidate the molecular link between receptor activation and membrane ruffling, we microinjected phosphorylated peptides containing YMXM motifs or a mutant 85 kDa subunit of phosphoinositide (PI) 3-kinase (delta p85) which lacks a binding site for the catalytic 110 kDa subunit of PI 3-kinase into the cytoplasm of human epidermoid carcinoma KB cells. Both inhibited the association of insulin receptor substrate-1 (IRS-1) with PI 3-kinase in a cell-free system and also inhibited insulin- or IGF-1-induced, but not EGF-induced, membrane ruffling in KB cells. Microinjection of nonphosphorylated analogues, phosphorylated peptides containing the EYYE motif or wild-type 85 kDa subunit (Wp85), all of which did not inhibit the association of IRS-1 with PI 3-kinase in a cell-free system, did not inhibit membrane ruffling in KB cells. In addition, wortmannin, an inhibitor of PI 3-kinase activity, inhibited insulin- or IGF-1-induced membrane ruffling. These results suggest that the association of IRS-1 with PI 3-kinase followed by the activation of PI 3-kinase are required for insulin- or IGF-1-induced, but not for EGF-induced, membrane ruffling. Images PMID:8194523

  8. MiR-18b suppresses high-glucose-induced proliferation in HRECs by targeting IGF-1/IGF1R signaling pathways.

    PubMed

    Wu, Jin-hui; Wang, Yi-han; Wang, Wei; Shen, Wei; Sang, Yan-zhi; Liu, Lin; Chen, Cui-min

    2016-04-01

    MicroRNAs (miRNAs) are important for the proliferation of endothelial cells and have been shown to be involved in diabetic retinopathy (DR). In previous study, we found that miRNAs might play a critical role in hyperglycemia-induced endothelial cell proliferation based on miRNA expression profiling. Here, the roles of microRNA-18b (miR-18b) in the proliferation of human retinal endothelial cells (HRECs) were investigated in an in vitro model of HRECs grown in high glucose. We identified that levels of miR-18b were decreased in high-glucose-induced HRECs, compared with those in cells incubated in normal glucose. However, the reduction of miR-18b up-regulated vascular endothelial growth factor (VEGF) secretion and promoted effects on in vitro proliferation of HRECs. Mechanistically, insulin growth factor-1 (IGF-1) was identified as a target of miR-18b. IGF-1 simulation could antagonize the effect induced by miR-18b up-regulation, promoting cell proliferation and increasing VEGF production. In contrast, the opposite results were observed with silencing IGF-1, which was consistent with the effects of miR-18b overexpression. MiR-18b exerted its function on VEGF synthesis and cell proliferation by suppressing the IGF-1/insulin growth factor-1 receptor (IGF1R) pathway, consequently inhibiting the downstream phosphorylation of Akt, MEK, and ERK. Hence, this may provide a new insight into understanding the mechanism of DR pathogenesis, as well as a potential therapeutic target for proliferative DR.

  9. Cardioprotective mIGF-1/SIRT1 signaling induces hypertension, leukocytosis and fear response in mice.

    PubMed

    Bolasco, Giulia; Calogero, Raffaele; Carrara, Matteo; Banchaabouchi, Mumna Al; Bilbao, Daniel; Mazzoccoli, Gianluigi; Vinciguerra, Manlio

    2012-06-01

    Locally acting insulin growth factor isoform (mIGF-1) and the NAD+-dependent protein deacetylase SIRT1 are implicated in life and health span. Heart failure is associated with aging and is a major cause of death. mIGF-1 protects the heart from oxidative stresses via SIRT1. SIRT1 subcellular localization and its genomic regulation by mIGF-1 are unknown. We show here that SIRT1 is located in the nuclei of a significant fraction of cardiomyocytes. Using high throughput sequencing approaches in mIGF-1 transgenic mice, we identified new targets of the mIGF-1/SIRT1 signaling. In addition to its potent cardioprotective properties, cardiac-restricted mIGF-1 transgene induced systemic changes such as high blood pressure, leukocytosis and an enhanced fear response, in a SIRT1-dependent manner. Cardiac mIGF-1/ SIRT1 signaling may thus modulate disparate systemic functions.

  10. The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling

    SciTech Connect

    Munoz, Juan Pablo; Collao, Andres; Chiong, Mario; Maldonado, Carola; Adasme, Tatiana; Carrasco, Loreto; Ocaranza, Paula; Bravo, Roberto; Gonzalez, Leticia; Diaz-Araya, Guillermo; Hidalgo, Cecilia; Lavandero, Sergio

    2009-10-09

    Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-induced MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal {alpha}-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression.

  11. Role of heterotrimeric G protein and calcium in cardiomyocyte hypertrophy induced by IGF-1.

    PubMed

    Carrasco, Loreto; Cea, Paola; Rocco, Paola; Peña-Oyarzún, Daniel; Rivera-Mejias, Pablo; Sotomayor-Flores, Cristian; Quiroga, Clara; Criollo, Alfredo; Ibarra, Cristian; Chiong, Mario; Lavandero, Sergio

    2014-04-01

    In the heart, insulin-like growth factor-1 (IGF-1) is a peptide with pro-hypertrophic and anti-apoptotic actions. The pro-hypertrophic properties of IGF-1 have been attributed to the extracellular regulated kinase (ERK) pathway. Recently, we reported that IGF-1 also increases intracellular Ca(2+) levels through a pertussis toxin (PTX)-sensitive G protein. Here we investigate whether this Ca(2+) signal is involved in IGF-1-induced cardiomyocyte hypertrophy. Our results show that the IGF-1-induced increase in Ca(2+) level is abolished by the IGF-1 receptor tyrosine kinase inhibitor AG538, PTX and the peptide inhibitor of Gβγ signaling, βARKct. Increases in the activities of Ca(2+) -dependent enzymes calcineurin, calmodulin kinase II (CaMKII), and protein kinase Cα (PKCα) were observed at 5 min after IGF-1 exposure. AG538, PTX, βARKct, and the dominant negative PKCα prevented the IGF-1-dependent phosphorylation of ERK1/2. Participation of calcineurin and CaMKII in ERK phosphorylation was discounted. IGF-1-induced cardiomyocyte hypertrophy, determined by cell size and β-myosin heavy chain (β-MHC), was prevented by AG538, PTX, βARKct, dominant negative PKCα, and the MEK1/2 inhibitor PD98059. Inhibition of calcineurin with CAIN did not abolish IGF-1-induced cardiac hypertrophy. We conclude that IGF-1 induces hypertrophy in cultured cardiomyocytes by activation of the receptor tyrosine kinase activity/βγ-subunits of a PTX-sensitive G protein/Ca(2+) /PKCα/ERK pathway without the participation of calcineurin.

  12. Role of IGF-1 in cortical plasticity and functional deficit induced by sensorimotor restriction.

    PubMed

    Mysoet, Julien; Dupont, Erwan; Bastide, Bruno; Canu, Marie-Hélène

    2015-09-01

    In the adult rat, sensorimotor restriction by hindlimb unloading (HU) is known to induce impairments in motor behavior as well as a disorganization of somatosensory cortex (shrinkage of the cortical representation of the hindpaw, enlargement of the cutaneous receptive fields, decreased cutaneous sensibility threshold). Recently, our team has demonstrated that IGF-1 level was decreased in the somatosensory cortex of rats submitted to a 14-day period of HU. To determine whether IGF-1 is involved in these plastic mechanisms, a chronic cortical infusion of this substance was performed by means of osmotic minipump. When administered in control rats, IGF-1 affects the size of receptive fields and the cutaneous threshold, but has no effect on the somatotopic map. In addition, when injected during the whole HU period, IGF-1 is interestingly implied in cortical changes due to hypoactivity: the shrinkage of somatotopic representation of hindlimb is prevented, whereas the enlargement of receptive fields is reduced. IGF-1 has no effect on the increase in neuronal response to peripheral stimulation. We also explored the functional consequences of IGF-1 level restoration on tactile sensory discrimination. In HU rats, the percentage of paw withdrawal after a light tactile stimulation was decreased, whereas it was similar to control level in HU-IGF-1 rats. Taken together, the data clearly indicate that IGF-1 plays a key-role in cortical plastic mechanisms and in behavioral alterations induced by a decrease in sensorimotor activity.

  13. Dietary protein-induced hepatic IGF-1 secretion mediated by PPARγ activation

    PubMed Central

    Wan, Xiaojuan; Wang, Songbo; Xu, Jingren; Zhuang, Lu; Xing, Kongping; Zhang, Mengyuan; Zhu, Xiaotong; Wang, Lina; Gao, Ping; Xi, Qianyun; Sun, Jiajie; Zhang, Yongliang; Li, Tiejun; Shu, Gang; Jiang, Qingyan

    2017-01-01

    Dietary protein or amino acid (AA) is a crucial nutritional factor to regulate hepatic insulin-like growth factor-1 (IGF-1) expression and secretion. However, the underlying intracellular mechanism by which dietary protein or AA induces IGF-1 expression remains unknown. We compared the IGF-1 gene expression and plasma IGF-1 level of pigs fed with normal crude protein (CP, 20%) and low-protein levels (LP, 14%). RNA sequencing (RNA-seq) was performed to detect transcript expression in the liver in response to dietary protein. The results showed that serum concentrations and mRNA levels of IGF-1 in the liver were higher in the CP group than in the LP group. RNA-seq analysis identified a total of 1319 differentially expressed transcripts (667 upregulated and 652 downregulated), among which the terms “oxidative phosphorylation”, “ribosome”, “gap junction”, “PPAR signaling pathway”, and “focal adhesion” were enriched. In addition, the porcine primary hepatocyte and HepG2 cell models also demonstrated that the mRNA and protein levels of IGF-1 and PPARγ increased with the increasing AA concentration in the culture. The PPARγ activator troglitazone increased IGF-1 gene expression and secretion in a dose dependent manner. Furthermore, inhibition of PPARγ effectively reversed the effects of the high AA concentration on the mRNA expression of IGF-1 and IGFBP-1 in HepG2 cells. Moreover, the protein levels of IGF-1 and PPARγ, as well as the phosphorylation of mTOR, significantly increased in HepG2 cells under high AA concentrations. mTOR phosphorylation can be decreased by the mTOR antagonist, rapamycin. The immunoprecipitation results also showed that high AA concentrations significantly increased the interaction of mTOR and PPARγ. In summary, PPARγ plays an important role in the regulation of IGF-1 secretion and gene expression in response to dietary protein. PMID:28257428

  14. Dietary protein-induced hepatic IGF-1 secretion mediated by PPARγ activation.

    PubMed

    Wan, Xiaojuan; Wang, Songbo; Xu, Jingren; Zhuang, Lu; Xing, Kongping; Zhang, Mengyuan; Zhu, Xiaotong; Wang, Lina; Gao, Ping; Xi, Qianyun; Sun, Jiajie; Zhang, Yongliang; Li, Tiejun; Shu, Gang; Jiang, Qingyan

    2017-01-01

    Dietary protein or amino acid (AA) is a crucial nutritional factor to regulate hepatic insulin-like growth factor-1 (IGF-1) expression and secretion. However, the underlying intracellular mechanism by which dietary protein or AA induces IGF-1 expression remains unknown. We compared the IGF-1 gene expression and plasma IGF-1 level of pigs fed with normal crude protein (CP, 20%) and low-protein levels (LP, 14%). RNA sequencing (RNA-seq) was performed to detect transcript expression in the liver in response to dietary protein. The results showed that serum concentrations and mRNA levels of IGF-1 in the liver were higher in the CP group than in the LP group. RNA-seq analysis identified a total of 1319 differentially expressed transcripts (667 upregulated and 652 downregulated), among which the terms "oxidative phosphorylation", "ribosome", "gap junction", "PPAR signaling pathway", and "focal adhesion" were enriched. In addition, the porcine primary hepatocyte and HepG2 cell models also demonstrated that the mRNA and protein levels of IGF-1 and PPARγ increased with the increasing AA concentration in the culture. The PPARγ activator troglitazone increased IGF-1 gene expression and secretion in a dose dependent manner. Furthermore, inhibition of PPARγ effectively reversed the effects of the high AA concentration on the mRNA expression of IGF-1 and IGFBP-1 in HepG2 cells. Moreover, the protein levels of IGF-1 and PPARγ, as well as the phosphorylation of mTOR, significantly increased in HepG2 cells under high AA concentrations. mTOR phosphorylation can be decreased by the mTOR antagonist, rapamycin. The immunoprecipitation results also showed that high AA concentrations significantly increased the interaction of mTOR and PPARγ. In summary, PPARγ plays an important role in the regulation of IGF-1 secretion and gene expression in response to dietary protein.

  15. Superoxide anion radicals induce IGF-1 resistance through concomitant activation of PTP1B and PTEN.

    PubMed

    Singh, Karmveer; Maity, Pallab; Krug, Linda; Meyer, Patrick; Treiber, Nicolai; Lucas, Tanja; Basu, Abhijit; Kochanek, Stefan; Wlaschek, Meinhard; Geiger, Hartmut; Scharffetter-Kochanek, Karin

    2015-01-01

    The evolutionarily conserved IGF-1 signalling pathway is associated with longevity, metabolism, tissue homeostasis, and cancer progression. Its regulation relies on the delicate balance between activating kinases and suppressing phosphatases and is still not very well understood. We report here that IGF-1 signalling in vitro and in a murine ageing model in vivo is suppressed in response to accumulation of superoxide anions (O2∙-) in mitochondria, either by chemical inhibition of complex I or by genetic silencing of O2∙--dismutating mitochondrial Sod2. The O2∙--dependent suppression of IGF-1 signalling resulted in decreased proliferation of murine dermal fibroblasts, affected translation initiation factors and suppressed the expression of α1(I), α1(III), and α2(I) collagen, the hallmarks of skin ageing. Enhanced O2∙- led to activation of the phosphatases PTP1B and PTEN, which via dephosphorylation of the IGF-1 receptor and phosphatidylinositol 3,4,5-triphosphate dampened IGF-1 signalling. Genetic and pharmacologic inhibition of PTP1B and PTEN abrogated O2∙--induced IGF-1 resistance and rescued the ageing skin phenotype. We thus identify previously unreported signature events with O2∙-, PTP1B, and PTEN as promising targets for drug development to prevent IGF-1 resistance-related pathologies.

  16. Insulin-like growth factor-binding protein-3 inhibits IGF-1-induced proliferation of human hepatocellular carcinoma cells by controlling bFGF and PDGF autocrine/paracrine loops.

    PubMed

    Ma, Yang; Han, Chen-Chen; Li, Yifan; Wang, Yang; Wei, Wei

    2016-09-16

    Basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) produced by hepatocellular carcinoma (HCC) cells are responsible for the growth of HCC cells. Accumulating evidence shows that insulin-like growth factor-binding protein-3 (IGFBP-3) suppresses HCC cell proliferation in both IGF-dependent and independent manners. It's unknown, however, whether treatment with exogenous IGFBP-3 inhibits bFGF and PDGF production in HCC cells. The present study demonstrates that IGFBP-3 suppressed IGF-1-induced bFGF and PDGF expression while it does not affect their expression in the absence of IGF-1. To delineate the underlying mechanism, western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1 (EGR1) is involved in IGFBP-3 regulation of bFGF and PDGF. IGFBP-3 inhibition of type 1 insulin-like growth factor receptor (IGF1R), ERK and AKT activation is IGF-1-dependent. Furthermore, transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1, bFGF and PDGF expression. In conclusion, these findings suggest that IGFBP-3 suppresses transcription of EGR1 and its target genes bFGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation. It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation, suggesting that IGFBP-3 could be a target for the treatment of HCC.

  17. Glucose induces apoptosis of cardiomyocytes via microRNA-1 and IGF-1.

    PubMed

    Yu, Xi-Yong; Song, Yao-Hua; Geng, Yong-Jian; Lin, Qiu-Xiong; Shan, Zhi-Xin; Lin, Shu-Guang; Li, Yangxin

    2008-11-21

    Glucose toxicity is an important initiator of cardiovascular disease, contributing to the development of cardiomyocyte death and diabetic complications. The present study investigated whether high glucose state could induce apoptosis of rat cardiomyocyte cell line H9C2 through microRNA regulated insulin-like growth factor (IGF-1) signaling pathway. Our data showed that H9C2 cells exposed to high glucose have increased miR-1 expression level, decreased mitochondrial membrane potential, increased cytochrome-c release, and increased apoptosis. Glucose induced mitochondrial dysfunction, cytochrome-c release and apoptosis was blocked by IGF-1. Using prediction algorithms, we identified 3'-untranslated regions of IGF-1 gene are the target of miR-1. miR-1 mimics, but not mutant miR-1, blocked the capacity of IGF-1 to prevent glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis. In conclusion, our data demonstrate that IGF-1 inhibits glucose-induced mitochondrial dysfunction, cytochrome-c release and apoptosis and IGF-1's effect is regulated by miR-1.

  18. Satellite cell dysfunction and impaired IGF-1 signaling cause CKD-induced muscle atrophy.

    PubMed

    Zhang, Liping; Wang, Xiaonan H; Wang, Huiling; Du, Jie; Mitch, William E

    2010-03-01

    Muscle wasting in chronic kidney disease (CKD) begins with impaired insulin/IGF-1 signaling, causing abnormal protein metabolism. In certain models of muscle atrophy, reduced satellite cell function contributes to atrophy, but how CKD affects satellite cell function is unknown. Here, we found that isolated satellite cells from mice with CKD had less MyoD, the master switch of satellite cell activation, and suppressed myotube formation compared with control mice. In vivo, CKD delayed the regeneration of injured muscle and decreased MyoD and myogenin expression, suggesting that CKD impairs proliferation and differentiation of satellite cells. In isolated satellite cells from control mice, IGF-1 increased the expression of myogenic genes through an Akt-dependent pathway. CKD impaired Akt phosphorylation in satellite cells after muscle injury. To test whether impaired IGF-1 signaling could be responsible for decreased satellite cell function in CKD, we created an inducible IGF-1 receptor knockout mouse and found impaired satellite cell function and muscle regeneration. In addition, both CKD and IGF-1 receptor knockout mice developed fibrosis in regenerating muscles. Taken together, impaired IGF-1 signaling in CKD not only leads to abnormal protein metabolism in muscle but also impairs satellite cell function and promotes fibrosis in regenerating muscle. These signaling pathways may hold potential therapeutic targets to reduce CKD-related muscle wasting.

  19. Single-cell analysis reveals IGF-1 potentiation of inhibition of the TGF-β/Smad pathway of fibrosis in human keratocytes in vitro

    PubMed Central

    Sarenac, Tomislav; Trapecar, Martin; Gradisnik, Lidija; Rupnik, Marjan Slak; Pahor, Dusica

    2016-01-01

    Corneal wound healing is often affected by TGF-β–mediated fibrosis and scar formation. Guided fibrosis with IGF-1 and antifibrotic substances might maintain corneal transparency. Primary human corneal keratocytes under serum-free conditions were used as a model of corneal stromal wounding, with markers of corneal fibrosis and opacity studied under TGF-β2 stimulation. Single-cell imaging flow cytometry was used to determine nuclearization of Smad3, and intracellular fluorescence intensity of Smad7 and the corneal crystallin aldehyde dehydrogenase 3A1. Extracellular matrix proteoglycans keratocan and biglycan were quantified using ELISAs. On the TGF-β2 background, the keratocytes were treated with IGF-1, and suberoylanilidehydroxamic acid (SAHA) or halofuginone ± IGF-1. IGF-1 alone decreased Smad3 nuclearization and increased aldehyde dehydrogenase 3A1 expression, with favorable extracellular matrix proteoglycan composition. SAHA induced higher Smad7 levels and inhibited translocation of Smad3 to the nucleus, also when combined with IGF-1. Immunofluorescence showed that myofibroblast transdifferentiation is attenuated and appearance of fibroblasts is favored by IGF-1 alone and in combination with the antifibrotic substances. The TGF-β/Smad pathway of fibrosis and opacity was inhibited by IGF-1, and further with SAHA in particular, and with halofuginone. IGF-1 is thus a valid aid to antifibrotic treatment, with potential for effective and transparent corneal wound healing. PMID:27687492

  20. Sensory experience regulates cortical inhibition by inducing IGF1 in VIP neurons.

    PubMed

    Mardinly, A R; Spiegel, I; Patrizi, A; Centofante, E; Bazinet, J E; Tzeng, C P; Mandel-Brehm, C; Harmin, D A; Adesnik, H; Fagiolini, M; Greenberg, M E

    2016-03-17

    Inhibitory neurons regulate the adaptation of neural circuits to sensory experience, but the molecular mechanisms by which experience controls the connectivity between different types of inhibitory neuron to regulate cortical plasticity are largely unknown. Here we show that exposure of dark-housed mice to light induces a gene program in cortical vasoactive intestinal peptide (VIP)-expressing neurons that is markedly distinct from that induced in excitatory neurons and other subtypes of inhibitory neuron. We identify Igf1 as one of several activity-regulated genes that are specific to VIP neurons, and demonstrate that IGF1 functions cell-autonomously in VIP neurons to increase inhibitory synaptic input onto these neurons. Our findings further suggest that in cortical VIP neurons, experience-dependent gene transcription regulates visual acuity by activating the expression of IGF1, thus promoting the inhibition of disinhibitory neurons and affecting inhibition onto cortical pyramidal neurons.

  1. Suppression of homologous recombination sensitizes human tumor cells to IGF-1R inhibition.

    PubMed

    Lodhia, Kunal A; Gao, Shan; Aleksic, Tamara; Esashi, Fumiko; Macaulay, Valentine M

    2015-06-15

    Inhibition of type 1 IGF receptor (IGF-1R) sensitizes to DNA-damaging cancer treatments, and delays repair of DNA double strand breaks (DSBs) by non-homologous end-joining and homologous recombination (HR). In a recent screen for mediators of resistance to IGF-1R inhibitor AZ12253801, we identified RAD51, required for the strand invasion step of HR. These findings prompted us to test the hypothesis that IGF-1R-inhibited cells accumulate DSBs formed at endogenous DNA lesions, and depend on residual HR for their repair. Indeed, initial experiments showed time-dependent accumulation of γH2AX foci in IGF-1R -inhibited or -depleted prostate cancer cells. We then tested effects of suppressing HR, and found that RAD51 depletion enhanced AZ12253801 sensitivity in PTEN wild-type prostate cancer cells but not in cells lacking functional PTEN. Similar sensitization was induced in prostate cancer cells by depletion of BRCA2, required for RAD51 loading onto DNA, and in BRCA2(-/-) colorectal cancer cells, compared with isogenic BRCA2(+/-) cells. We also assessed chemical HR inhibitors, finding that RAD51 inhibitor BO2 blocked RAD51 focus formation and sensitized to AZ12253801. Finally, we tested CDK1 inhibitor RO-3306, which impairs HR by inhibiting CDK1-mediated BRCA1 phosphorylation. R0-3306 suppressed RAD51 focus formation consistent with HR attenuation, and sensitized prostate cancer cells to IGF-1R inhibition, with 2.4-fold reduction in AZ12253801 GI50 and 13-fold reduction in GI80. These data suggest that responses to IGF-1R inhibition are enhanced by genetic and chemical approaches to suppress HR, defining a population of cancers (PTEN wild-type, BRCA mutant) that may be intrinsically sensitive to IGF-1R inhibitory drugs.

  2. Growth Hormone Ameliorates the Radiotherapy-Induced Ovarian Follicular Loss in Rats: Impact on Oxidative Stress, Apoptosis and IGF-1/IGF-1R Axis

    PubMed Central

    Mahran, Yasmen F.; El-Demerdash, Ebtehal; Nada, Ahmed S.; El-Naga, Reem N.; Ali, Azza A.; Abdel-Naim, Ashraf B.

    2015-01-01

    Radiotherapy is one of the standard cytotoxic therapies for cancer. However, it has a profound impact on ovarian function leading to premature ovarian failure and infertility. Since none of the currently available methods for fertility preservation guarantees future fertility, the need for an effective radioprotective agent is highly intensified. The present study investigated the mechanisms of the potential radioprotective effect of growth hormone (GH) on γ irradiation-induced ovarian failure and the impact of the insulin like growth factor 1 (IGF-1) in the underlying protection. Immature female Sprague-Dawley rats were either exposed to single whole body irradiation (3.2 Gy) and/or treated with GH (1 mg/kg s.c). Experimental γ-irradiation produced an array of ovarian dysfunction that was evident by assessment of hormonal changes, follicular development, proliferation marker (PCNA), oxidative stress as well as apoptotic markers. In addition, IGF-1/IGF-1R axis expression was assessed using real-time PCR and immunolocalization techniques. Furthermore, after full maturity, fertility assessment was performed. GH significantly enhanced follicular development and restored anti-Mullerian hormone serum level as compared with the irradiated group. In addition, GH significantly ameliorated the deleterious effects of irradiation on oxidative status, PCNA and apoptosis. Interestingly, GH was shown to enhance the ovarian IGF-1 at transcription and translation levels, a property that contributes significantly to its radioprotective effect. Finally, GH regained the fertility that was lost following irradiation. In conclusion, GH showed a radioprotective effect and rescued the ovarian reserve through increasing local IGF-1 level and counteracting the oxidative stress-mediated apoptosis. PMID:26465611

  3. Growth Hormone Ameliorates the Radiotherapy-Induced Ovarian Follicular Loss in Rats: Impact on Oxidative Stress, Apoptosis and IGF-1/IGF-1R Axis.

    PubMed

    Mahran, Yasmen F; El-Demerdash, Ebtehal; Nada, Ahmed S; El-Naga, Reem N; Ali, Azza A; Abdel-Naim, Ashraf B

    2015-01-01

    Radiotherapy is one of the standard cytotoxic therapies for cancer. However, it has a profound impact on ovarian function leading to premature ovarian failure and infertility. Since none of the currently available methods for fertility preservation guarantees future fertility, the need for an effective radioprotective agent is highly intensified. The present study investigated the mechanisms of the potential radioprotective effect of growth hormone (GH) on γ irradiation-induced ovarian failure and the impact of the insulin like growth factor 1 (IGF-1) in the underlying protection. Immature female Sprague-Dawley rats were either exposed to single whole body irradiation (3.2 Gy) and/or treated with GH (1 mg/kg s.c). Experimental γ-irradiation produced an array of ovarian dysfunction that was evident by assessment of hormonal changes, follicular development, proliferation marker (PCNA), oxidative stress as well as apoptotic markers. In addition, IGF-1/IGF-1R axis expression was assessed using real-time PCR and immunolocalization techniques. Furthermore, after full maturity, fertility assessment was performed. GH significantly enhanced follicular development and restored anti-Mullerian hormone serum level as compared with the irradiated group. In addition, GH significantly ameliorated the deleterious effects of irradiation on oxidative status, PCNA and apoptosis. Interestingly, GH was shown to enhance the ovarian IGF-1 at transcription and translation levels, a property that contributes significantly to its radioprotective effect. Finally, GH regained the fertility that was lost following irradiation. In conclusion, GH showed a radioprotective effect and rescued the ovarian reserve through increasing local IGF-1 level and counteracting the oxidative stress-mediated apoptosis.

  4. Expression of Recombinant Human Insulin-like Growth Factor Type 1 (rhIGF-1) in Escherichia coli

    PubMed Central

    Iranpoor, Hamidreza; Omidinia, Eskandar; Vatankhah, Venus; Gharanjik, Vahid; Shahbazi, Majid

    2015-01-01

    Background: Human insulin-like growth factor type 1 (hIGF-1) is a protein consisting of 70 amino acids (MW=7.6 kDa) and mainly synthesized by liver. Mecasermin (Trade name INCRELEX) is the synthetic form of the protein which is used as an effective treatment for particular disorders such as short stature, type 1 and 2 diabetes, and wound healing. Current study was aimed to investigate the expression of human insulin-like growth factor type1 in Escherichia coli (E. coli) BL21 (DE3) expression system in order to produce an active recombinant form of the protein. Methods: For the purpose of the study, firstly codon optimization was done for hIGF-1 gene, using bioinformatics databases. Then, the gene was synthesized and inserted in pET-24a vector by a cutting strategy included NdeI and BamHI-HF enzymes. In the next step, gene was run in agarose gel and purified. The constructed expression cassette was transformed into E. coli BL21 (DE3) cells through CaCl 2 heat shock method. Identification and confirmation of the transformed colonies were performed using screening PCR method. Synthesis of hIGF-1 was induced by IPTG. The expression in induced strains was analyzed by SDS-PAGE and western blotting techniques. Confirmation of cloning and IGF-1 expression cassette was carried out through genetic engineering procedures. Results: Analysis of transformed E. coli strain with SDS-PAGE and western blotting techniques confirmed that gene was expressed in host cells. Molecular weight of the expressed protein was estimated to be 7.6 kDa. Conclusion: hIGF-1 expression cassette for cloning and expression in E. coli was designed and the protein of interest was successfully induced and identified. In addition, E. coli BL21 (DE3) can be used as a suitable host for production of recombinant hIGF-1 and this technology has a potential to be localized. PMID:26306149

  5. NO-1886 suppresses diet-induced insulin resistance and cholesterol accumulation through STAT5-dependent upregulation of IGF1 and CYP7A1.

    PubMed

    Li, Qinkai; Yin, Weidong; Cai, Manbo; Liu, Yi; Hou, Hongjie; Shen, Qingyun; Zhang, Chi; Xiao, Junxia; Hu, Xiaobo; Wu, Qishisan; Funaki, Makoto; Nakaya, Yutaka

    2010-01-01

    Insulin resistance and dyslipidemia are both considered to be risk factors for metabolic syndrome. Low levels of IGF1 are associated with insulin resistance. Elevation of low-density lipoprotein cholesterol (LDL-C) concomitant with depression of high-density lipoprotein cholesterol (HDL-C) increase the risk of obesity and type 2 diabetes mellitus (T2DM). Liver secretes IGF1 and catabolizes cholesterol regulated by the rate-limiting enzyme of bile acid synthesis from cholesterol 7alpha-hydroxylase (CYP7A1). NO-1886, a chemically synthesized lipoprotein lipase activator, suppresses diet-induced insulin resistance with the improvement of HDL-C. The goal of the present study is to evaluate whether NO-1886 upregulates IGF1 and CYP7A1 to benefit glucose and cholesterol metabolism. By using human hepatoma cell lines (HepG2 cells) as an in vitro model, we found that NO-1886 promoted IGF1 secretion and CYP7A1 expression through the activation of signal transducer and activator of transcription 5 (STAT5). Pretreatment of cells with AG 490, the inhibitor of STAT pathway, completely abolished NO-1886-induced IGF1 secretion and CYP7A1 expression. Studies performed in Chinese Bama minipigs pointed out an augmentation of plasma IGF1 elicited by a single dose administration of NO-1886. Long-term supplementation with NO-1886 recovered hyperinsulinemia and low plasma levels of IGF1 suppressed LDL-C and facilitated reverse cholesterol transport by decreasing hepatic cholesterol accumulation through increasing CYP7A1 expression in high-fat/high-sucrose/high-cholesterol diet minipigs. These findings indicate that NO-1886 upregulates IGF1 secretion and CYP7A1 expression to improve insulin resistance and hepatic cholesterol accumulation, which may represent an alternative therapeutic avenue of NO-1886 for T2DM and metabolic syndrome.

  6. IGF-1 drives chromogranin A secretion via activation of Arf1 in human neuroendocrine tumour cells

    PubMed Central

    Münzberg, Christin; Höhn, Katharina; Krndija, Denis; Maaß, Ulrike; Bartsch, Detlef K; Slater, Emily P; Oswald, Franz; Walther, Paul; Seufferlein, Thomas; von Wichert, Götz

    2015-01-01

    Hypersecretion is the major symptom of functional neuroendocrine tumours. The mechanisms that contribute to this excessive secretion of hormones are still elusive. A key event in secretion is the exit of secretory products from the Golgi apparatus. ADP-ribosylation factor (Arf) GTPases are known to control vesicle budding and trafficking, and have a leading function in the regulation of formation of secretory granula at the Golgi. Here, we show that Arf1 is the predominant Arf protein family member expressed in the neuroendocrine pancreatic tumour cell lines BON and QGP-1. In BON cells Arf1 colocalizes with Golgi markers as well as chromogranin A, and shows significant basal activity. The inhibition of Arf1 activity or expression significantly impaired secretion of chromogranin A. Furthermore, we show that the insulin-like growth factor 1 (IGF-1), a major regulator of growth and secretion in BON cells, induces Arf1 activity. We found that activation of Arf1 upon IGF-1 receptor stimulation is mediated by MEK/ERK signalling pathway in BON and QGP-1 cells. Moreover, the activity of Arf1 in BON cells is mediated by autocrinely secreted IGF-1, and concomitantly, autocrine IGF1 secretion is maintained by Arf1 activity. In summary, our data indicate an important regulatory role for Arf1 at the Golgi in hypersecretion in neuroendocrine cancer cells. PMID:25754106

  7. IGF-1 drives chromogranin A secretion via activation of Arf1 in human neuroendocrine tumour cells.

    PubMed

    Münzberg, Christin; Höhn, Katharina; Krndija, Denis; Maaß, Ulrike; Bartsch, Detlef K; Slater, Emily P; Oswald, Franz; Walther, Paul; Seufferlein, Thomas; von Wichert, Götz

    2015-05-01

    Hypersecretion is the major symptom of functional neuroendocrine tumours. The mechanisms that contribute to this excessive secretion of hormones are still elusive. A key event in secretion is the exit of secretory products from the Golgi apparatus. ADP-ribosylation factor (Arf) GTPases are known to control vesicle budding and trafficking, and have a leading function in the regulation of formation of secretory granula at the Golgi. Here, we show that Arf1 is the predominant Arf protein family member expressed in the neuroendocrine pancreatic tumour cell lines BON and QGP-1. In BON cells Arf1 colocalizes with Golgi markers as well as chromogranin A, and shows significant basal activity. The inhibition of Arf1 activity or expression significantly impaired secretion of chromogranin A. Furthermore, we show that the insulin-like growth factor 1 (IGF-1), a major regulator of growth and secretion in BON cells, induces Arf1 activity. We found that activation of Arf1 upon IGF-1 receptor stimulation is mediated by MEK/ERK signalling pathway in BON and QGP-1 cells. Moreover, the activity of Arf1 in BON cells is mediated by autocrinely secreted IGF-1, and concomitantly, autocrine IGF1 secretion is maintained by Arf1 activity. In summary, our data indicate an important regulatory role for Arf1 at the Golgi in hypersecretion in neuroendocrine cancer cells.

  8. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    NASA Astrophysics Data System (ADS)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui; Yang, Lily

    2016-05-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer.

  9. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    PubMed Central

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui

    2016-01-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer. PMID:27313332

  10. Human insulin/IGF-1 and familial longevity at middle age

    PubMed Central

    Rozing, Maarten P.; Westendorp, Rudi G.J.; Frölich, Marijke; de Craen, Anton J.M.; Beekman, Marian; Heijmans, Bastiaan T.; Mooijaart, Simon P.; Blauw, Gerard-Jan; Slagboom, P. Eline; van Heemst, Diana; Group, on behalf of the Leiden Longevity Study (LLS)

    2009-01-01

    Recently, we have shown that compared to controls, long-lived familial nonagenarians (mean age: 93.4 years) from the Leiden Longevity Study displayed a lower mortality rate, and their middle-aged offspring displayed a lower prevalence of cardio-metabolic diseases, including diabetes mellitus. The evolutionarily conserved insulin/IGF-1 signaling (IIS) pathway has been implicated in longevity in model organisms, but its relevance for human longevity has generated much controversy. Here, we show that compared to their partners, the offspring of familial nonagenarians displayed similar non-fasted serum levels of IGF-1, IGFBP3 and insulin but lower non-fasted serum levels of glucose, indicating that familial longevity is associated with differences in insulin sensitivity. PMID:20157552

  11. The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1β

    PubMed Central

    Miller, Mark JS; Ahmed, Salahuddin; Bobrowski, Paul; Haqqi, Tariq M

    2006-01-01

    Background Cartilage loss is a hallmark of arthritis and follows activation of catabolic processes concomitant with a disruption of anabolic pathways like insulin-like growth factor 1 (IGF-1). We hypothesized that two natural products of South American origin, would limit cartilage degradation by respectively suppressing catabolism and activating local IGF-1 anabolic pathways. One extract, derived from cat's claw (Uncaria guianensis, vincaria®), is a well-described inhibitor of NF-κB. The other extract, derived from the vegetable Lepidium meyenii (RNI 249), possessed an uncertain mechanism of action but with defined ethnomedical applications for fertility and vitality. Methods Human cartilage samples were procured from surgical specimens with consent, and were evaluated either as explants or as primary chondrocytes prepared after enzymatic digestion of cartilage matrix. Assessments included IGF-1 gene expression, IGF-1 production (ELISA), cartilage matrix degradation and nitric oxide (NO) production, under basal conditions and in the presence of IL-1β. Results RNI 249 enhanced basal IGF-1 mRNA levels in human chondrocytes by 2.7 fold, an effect that was further enhanced to 3.8 fold by co-administration with vincaria. Enhanced basal IGF-1 production by RNI 249 alone and together with vincaria, was confirmed in both explants and in primary chondrocytes (P <0.05). As expected, IL-1β exposure completely silenced IGF-1 production by chondrocytes. However, in the presence of IL-1β both RNI 249 and vincaria protected IGF-1 production in an additive manner (P <0.01) with the combination restoring chondrocyte IGF-1 production to normal levels. Cartilage NO production was dramatically enhanced by IL-1β. Both vincaria and RNI 249 partially attenuated NO production in an additive manner (p < 0.05). IL-1β – induced degradation of cartilage matrix was quantified as glycosaminoglycan release. Individually RNI 249 or vincaria, prevented this catabolic action of IL-1

  12. Co-Targeting IGF-1R and Autophagy Enhances the Effects of Cell Growth Suppression and Apoptosis Induced by the IGF-1R Inhibitor NVP-AEW541 in Triple-Negative Breast Cancer Cells

    PubMed Central

    Shao, Nan; Shi, Yawei; Liu, Ruiming; Li, Wen; Lin, Yin; Wang, Shenming

    2017-01-01

    Background Triple-negative breast cancer (TNBC) is the most intractable type of breast cancer, and there is a lack of effective targeted therapy. Insulin-like growth factor-1 receptor (IGF-1R) is reportedly a potential target for TNBC treatment. However, satisfying treatment outcomes in breast cancer patients have yet to be achieved with IGF-1R-targeted agents. Methods To confirm whether inhibiting IGF-1R could induce autophagy, we detected autophagy-related proteins by western blotting and immunofluorescence staining of LC3-II. The IGF-1R inhibitor NVP-AEW541, autophagy inhibitor 3-methyladenine (3-MA) and Atg7 small interfering RNA (siRNA) were used to further investigate the effects of autophagy induced by IGF-1R inhibition in TNBC cells. The CCK8 assay, EdU assay, apoptosis and cell cycle analyses were applied to test cell function after treatment. Results NVP-AEW541 markedly induced autophagy in TNBC cells by increasing the levels of the autophagy-related protein Beclin-1 and the LC3-II/LC-I ratio and reducing the selective autophagy substrate p62. Joint application of 3-MA or Atg7 siRNA enhanced the cell growth inhibition and apoptosis effects of NVP-AEW541 by arresting cells at G1/G0 phase and increasing Bax expression and decreasing that of Bcl-2. Conclusion Targeting IGF-1R in TNBC induces cell-protective autophagy, thereby weakening the therapeutic effect of agents directed toward IGF-1R. Our findings reveal that combined use autophagy-disrupting agents can enhance the therapeutic efficacy of IGF-1R inhibitors in TNBC cells and may provide a valuable treatment strategy for IGF-1R inhibitor-based therapies for TNBC and other IGF-1 signaling-associated tumors. PMID:28046018

  13. Transplantation of Human Neural Progenitor Cells Expressing IGF-1 Enhances Retinal Ganglion Cell Survival

    PubMed Central

    Guo, Caiwei; Sun, Yu; Liao, Tiffany; Beattie, Ursula; López, Francisco J.; Chen, Dong Feng; Lashkari, Kameran

    2015-01-01

    We have previously characterized human neuronal progenitor cells (hNP) that can adopt a retinal ganglion cell (RGC)-like morphology within the RGC and nerve fiber layers of the retina. In an effort to determine whether hNPs could be used a candidate cells for targeted delivery of neurotrophic factors (NTFs), we evaluated whether hNPs transfected with an vector that expresses IGF-1 in the form of a fusion protein with tdTomato (TD), would increase RGC survival in vitro and confer neuroprotective effects in a mouse model of glaucoma. RGCs co-cultured with hNPIGF-TD cells displayed enhanced survival, and increased neurite extension and branching as compared to hNPTD or untransfected hNP cells. Application of various IGF-1 signaling blockers or IGF-1 receptor antagonists abrogated these effects. In vivo, using a model of glaucoma we showed that IOP elevation led to reductions in retinal RGC count. In this model, evaluation of retinal flatmounts and optic nerve cross sections indicated that only hNPIGF-TD cells effectively reduced RGC death and showed a trend to improve optic nerve axonal loss. RT-PCR analysis of retina lysates over time showed that the neurotrophic effects of IGF-1 were also attributed to down-regulation of inflammatory and to some extent, angiogenic pathways. This study shows that neuronal progenitor cells that hone into the RGC and nerve fiber layers may be used as vehicles for local production and delivery of a desired NTF. Transplantation of hNPIGF-TD cells improves RGC survival in vitro and protects against RGC loss in a rodent model of glaucoma. Our findings have provided experimental evidence and form the basis for applying cell-based strategies for local delivery of NTFs into the retina. Application of cell-based delivery may be extended to other disease conditions beyond glaucoma. PMID:25923430

  14. ERG deregulation induces IGF-1R expression in prostate cancer cells and affects sensitivity to anti-IGF-1R agents.

    PubMed

    Mancarella, Caterina; Casanova-Salas, Irene; Calatrava, Ana; Ventura, Selena; Garofalo, Cecilia; Rubio-Briones, José; Magistroni, Vera; Manara, Maria Cristina; López-Guerrero, José Antonio; Scotlandi, Katia

    2015-06-30

    Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostate cancer (PCa). We investigated the molecular relationship between TMPRSS2-ERG (T2E) fusion gene and insulin-like growth factor receptor (IGF-1R) to optimize the use of IGF-1R inhibitors.IGF-1R was analyzed in cell lines and in radical prostatectomy specimens in relation to T2E status. ERG binding to IGF-1R promoter was evaluated by chromatin immunoprecipitation (ChIP). Sensitivity to anti-IGF-1R agents was evaluated alone or in combination with anti-androgen abiraterone acetate in vitro at basal levels or upon ERG modulation.IGF-1R analysis performed in PCa cells or clinical samples showed that T2E expression correlated with higher IGF-1R expression at mRNA and protein levels. Genetic modulation of ERG directly affected IGF-1R protein levels in vitro. ChIP analysis showed that ERG binds IGF-1R promoter and that promoter occupancy is higher in T2E-positive cells. IGF-1R inhibition was more effective in cell lines expressing the fusion gene and combination of IGF-1R inhibitors with abiraterone acetate produced synergistic effects in T2E-expressing cells.Here, we provide the rationale for use of T2E fusion gene to select PCa patients for anti-IGF-1R treatments. The combination of anti-IGF-1R-HAbs with an anti-androgen therapy is strongly advocated for patients expressing T2E.

  15. ERG deregulation induces IGF-1R expression in prostate cancer cells and affects sensitivity to anti-IGF-1R agents

    PubMed Central

    Mancarella, Caterina; Casanova-Salas, Irene; Calatrava, Ana; Ventura, Selena; Garofalo, Cecilia; Rubio-Briones, José; Magistroni, Vera; Manara, Maria Cristina; López-Guerrero, José Antonio; Scotlandi, Katia

    2015-01-01

    Identifying patients who may benefit from targeted therapy is an urgent clinical issue in prostate cancer (PCa). We investigated the molecular relationship between TMPRSS2-ERG (T2E) fusion gene and insulin-like growth factor receptor (IGF-1R) to optimize the use of IGF-1R inhibitors. IGF-1R was analyzed in cell lines and in radical prostatectomy specimens in relation to T2E status. ERG binding to IGF-1R promoter was evaluated by chromatin immunoprecipitation (ChIP). Sensitivity to anti-IGF-1R agents was evaluated alone or in combination with anti-androgen abiraterone acetate in vitro at basal levels or upon ERG modulation. IGF-1R analysis performed in PCa cells or clinical samples showed that T2E expression correlated with higher IGF-1R expression at mRNA and protein levels. Genetic modulation of ERG directly affected IGF-1R protein levels in vitro. ChIP analysis showed that ERG binds IGF-1R promoter and that promoter occupancy is higher in T2E-positive cells. IGF-1R inhibition was more effective in cell lines expressing the fusion gene and combination of IGF-1R inhibitors with abiraterone acetate produced synergistic effects in T2E-expressing cells. Here, we provide the rationale for use of T2E fusion gene to select PCa patients for anti-IGF-1R treatments. The combination of anti-IGF-1R-HAbs with an anti-androgen therapy is strongly advocated for patients expressing T2E. PMID:25906745

  16. IGF-1 induces skeletal myocyte hypertrophy through calcineurin in association with GATA-2 and NF-ATc1

    NASA Technical Reports Server (NTRS)

    Musaro, A.; McCullagh, K. J.; Naya, F. J.; Olson, E. N.; Rosenthal, N.

    1999-01-01

    Localized synthesis of insulin-like growth factors (IGFs) has been broadly implicated in skeletal muscle growth, hypertrophy and regeneration. Virally delivered IGF-1 genes induce local skeletal muscle hypertrophy and attenuate age-related skeletal muscle atrophy, restoring and improving muscle mass and strength in mice. Here we show that the molecular pathways underlying the hypertrophic action of IGF-1 in skeletal muscle are similar to those responsible for cardiac hypertrophy. Transfected IGF-1 gene expression in postmitotic skeletal myocytes activates calcineurin-mediated calcium signalling by inducing calcineurin transcripts and nuclear localization of calcineurin protein. Expression of activated calcineurin mimics the effects of IGF-1, whereas expression of a dominant-negative calcineurin mutant or addition of cyclosporin, a calcineurin inhibitor, represses myocyte differentiation and hypertrophy. Either IGF-1 or activated calcineurin induces expression of the transcription factor GATA-2, which accumulates in a subset of myocyte nuclei, where it associates with calcineurin and a specific dephosphorylated isoform of the transcription factor NF-ATc1. Thus, IGF-1 induces calcineurin-mediated signalling and activation of GATA-2, a marker of skeletal muscle hypertrophy, which cooperates with selected NF-ATc isoforms to activate gene expression programs.

  17. CD99 triggering induces methuosis of Ewing sarcoma cells through IGF-1R/RAS/Rac1 signaling

    PubMed Central

    Manara, Maria Cristina; Terracciano, Mario; Mancarella, Caterina; Sciandra, Marika; Guerzoni, Clara; Pasello, Michela; Grilli, Andrea; Zini, Nicoletta; Picci, Piero; Colombo, Mario P.; Morrione, Andrea; Scotlandi, Katia

    2016-01-01

    CD99 is a cell surface molecule that has emerged as a novel target for Ewing sarcoma (EWS), an aggressive pediatric bone cancer. This report provides the first evidence of methuosis in EWS, a non-apoptotic form of cell death induced by an antibody directed against the CD99 molecule. Upon mAb triggering, CD99 induces an IGF-1R/RAS/Rac1 complex, which is internalized into RAB5-positive endocytic vacuoles. This complex is then dissociated, with the IGF-1R recycling to the cell membrane while CD99 and RAS/Rac1 are sorted into immature LAMP-1-positive vacuoles, whose excessive accumulation provokes methuosis. This process, which is not detected in CD99-expressing normal mesenchymal cells, is inhibited by disruption of the IGF-1R signaling, whereas enhanced by IGF-1 stimulation. Induction of IGF-1R/RAS/Rac1 was also observed in the EWS xenografts that respond to anti-CD99 mAb, further supporting the role of the IGF/RAS/Rac1 axis in the hyperstimulation of macropinocytosis and selective death of EWS cells. Thus, we describe a vulnerability of EWS cells, including those resistant to standard chemotherapy, to a treatment with anti-CD99 mAb, which requires IGF-1R/RAS signaling but bypasses the need for their direct targeting. Overall, we propose CD99 targeting as new opportunity to treat EWS patients resistant to canonical apoptosis-inducing agents. PMID:27835596

  18. Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: A new potential therapy for the treatment of melanoma

    SciTech Connect

    Karasic, Thomas B.; Hei, Tom K.; Ivanov, Vladimir N.

    2010-07-15

    Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1]. All these lines have normal NRAS. WM35, WM793, LU1205 and WM9 cells have mutated BRAF (V600E). WM35 and WM9 cells express normal PTEN, while in WM793 cells PTEN expression is down-regulated; finally, in LU1205 cells PTEN is inactivated by mutation. Cyclolignan picropodophyllin (PPP), a specific inhibitor of IGF-1R kinase activity, strongly down-regulated the basal levels of AKT activity in WM9 and in WM793 cells, modestly does so in LU1205, but has no effect on AKT activity in the early stage WM35 cells that are deficient in IGF-1R. In addition, PPP partially down-regulated the basal levels of active ERK1/2 in all lines used, highlighting the role of an alternative, non-BRAF pathway in MAPK activation. The final result of PPP treatment was an induction of apoptosis in WM793, WM9 and LU1205 melanoma cells. On the other hand, dose-dependent inhibition of IGF-1R kinase activity by PPP at a relatively narrow dose range (near 500 nM) has different effects on melanoma cells versus normal cells, inducing apoptosis in cancer cells and G2/M arrest of fibroblasts. To further enhance the pro-apoptotic effects of PPP on melanoma cells, we used a combined treatment of TNF-Related Apoptosis-Inducing Ligand (TRAIL) and PPP. This combination substantially increased death by apoptosis for

  19. New insights into the relationship between mIGF-1-induced hypertrophy and Ca2+ handling in differentiated satellite cells.

    PubMed

    Guarnieri, Simone; Morabito, Caterina; Belia, Silvia; Barberi, Laura; Musarò, Antonio; Fanò-Illic, Giorgio; Mariggiò, Maria A

    2014-01-01

    Muscle regeneration involves the activation of satellite cells, is regulated at the genetic and epigenetic levels, and is strongly influenced by gene activation and environmental conditions. The aim of this study was to determine whether the overexpression of mIGF-1 can modify functional features of satellite cells during the differentiation process, particularly in relation to modifications of intracellular Ca2+ handling. Satellite cells were isolated from wild-type and MLC/mIGF-1 transgenic mice. The cells were differentiated in vitro, and morphological analyses, intracellular Ca2+ measurements, and ionic current recordings were performed. mIGF-1 overexpression accelerates satellite cell differentiation and promotes myotube hypertrophy. In addition, mIGF-1 overexpression-induced potentiation of myogenesis triggers both quantitative and qualitative changes to the control of intracellular Ca2+ handling. In particular, the differentiated MLC/mIGF-1 transgenic myotubes have reduced velocity and amplitude of intracellular Ca2+ increases after stimulation with caffeine, KCl and acetylcholine. This appears to be due, at least in part, to changes in the physico-chemical state of the sarcolemma (increased membrane lipid oxidation, increased output currents) and to increased expression of dihydropyridine voltage-operated Ca2+ channels. Interestingly, extracellular ATP and GTP evoke intracellular Ca2+ mobilization to greater extents in the MLC/mIGF-1 transgenic satellite cells, compared to the wild-type cells. These data suggest that these MLC/mIGF-1 transgenic satellite cells are more sensitive to trophic stimuli, which can potentiate the effects of mIGF-1 on the myogenic programme.

  20. Activation of IGF-1 and insulin signaling pathways ameliorate mitochondrial function and energy metabolism in Huntington's Disease human lymphoblasts.

    PubMed

    Naia, Luana; Ferreira, I Luísa; Cunha-Oliveira, Teresa; Duarte, Ana I; Ribeiro, Márcio; Rosenstock, Tatiana R; Laço, Mário N; Ribeiro, Maria J; Oliveira, Catarina R; Saudou, Frédéric; Humbert, Sandrine; Rego, A Cristina

    2015-02-01

    Huntington's disease (HD) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the huntingtin protein. Mitochondrial dysfunction associated with energy failure plays an important role in this untreated pathology. In the present work, we used lymphoblasts obtained from HD patients or unaffected parentally related individuals to study the protective role of insulin-like growth factor 1 (IGF-1) versus insulin (at low nM) on signaling and metabolic and mitochondrial functions. Deregulation of intracellular signaling pathways linked to activation of insulin and IGF-1 receptors (IR,IGF-1R), Akt, and ERK was largely restored by IGF-1 and, at a less extent, by insulin in HD human lymphoblasts. Importantly, both neurotrophic factors stimulated huntingtin phosphorylation at Ser421 in HD cells. IGF-1 and insulin also rescued energy levels in HD peripheral cells, as evaluated by increased ATP and phosphocreatine, and decreased lactate levels. Moreover, IGF-1 effectively ameliorated O2 consumption and mitochondrial membrane potential (Δψm) in HD lymphoblasts, which occurred concomitantly with increased levels of cytochrome c. Indeed, constitutive phosphorylation of huntingtin was able to restore the Δψm in lymphoblasts expressing an abnormal expansion of polyglutamines. HD lymphoblasts further exhibited increased intracellular Ca(2+) levels before and after exposure to hydrogen peroxide (H2O2), and decreased mitochondrial Ca(2+) accumulation, being the later recovered by IGF-1 and insulin in HD lymphoblasts pre-exposed to H2O2. In summary, the data support an important role for IR/IGF-1R mediated activation of signaling pathways and improved mitochondrial and metabolic function in HD human lymphoblasts.

  1. Insulin-like growth factor-1 (IGF-1)-induced processing of amyloid-beta precursor protein (APP) and APP-like protein 2 is mediated by different metalloproteinases.

    PubMed

    Jacobsen, Kristin T; Adlerz, Linda; Multhaup, Gerd; Iverfeldt, Kerstin

    2010-04-02

    alpha-Secretase cleavage of the amyloid precursor protein (APP) is of great interest because it prevents the formation of the Alzheimer-linked amyloid-beta peptide. APP belongs to a conserved gene family including the two paralogues APP-like protein (APLP) 1 and 2. Insulin-like growth factor-1 (IGF-1) stimulates the shedding of all three proteins. IGF-1-induced shedding of both APP and APLP1 is dependent on phosphatidylinositol 3-kinase (PI3-K), whereas APLP2 shedding is independent of this signaling pathway. Here, we used human neuroblastoma SH-SY5Y cells to investigate the involvement of protein kinase C (PKC) in the proteolytic processing of endogenously expressed members of the APP family. Processing was induced by IGF-1 or retinoic acid, another known stimulator of APP alpha-secretase shedding. Our results show that stimulation of APP and APLP1 processing involves multiple signaling pathways, whereas APLP2 processing is mainly dependent on PKC. Next, we wanted to investigate whether the difference in the regulation of APLP2 shedding compared with APP shedding could be due to involvement of different processing enzymes. We focused on the two major alpha-secretase candidates ADAM10 and TACE, which both are members of the ADAM (a disintegrin and metalloprotease) family. Shedding was analyzed in the presence of the ADAM10 inhibitor GI254023X, or after transfection with small interfering RNAs targeted against TACE. The results clearly demonstrate that different alpha-secretases are involved in IGF-1-induced processing. APP is mainly cleaved by ADAM10, whereas APLP2 processing is mediated by TACE. Finally, we also show that IGF-1 induces PKC-dependent phosphorylation of TACE.

  2. Insulin-like Growth Factor-1 (IGF-1)-induced Processing of Amyloid-β Precursor Protein (APP) and APP-like Protein 2 Is Mediated by Different Metalloproteinases*

    PubMed Central

    Jacobsen, Kristin T.; Adlerz, Linda; Multhaup, Gerd; Iverfeldt, Kerstin

    2010-01-01

    α-Secretase cleavage of the amyloid precursor protein (APP) is of great interest because it prevents the formation of the Alzheimer-linked amyloid-β peptide. APP belongs to a conserved gene family including the two paralogues APP-like protein (APLP) 1 and 2. Insulin-like growth factor-1 (IGF-1) stimulates the shedding of all three proteins. IGF-1-induced shedding of both APP and APLP1 is dependent on phosphatidylinositol 3-kinase (PI3-K), whereas APLP2 shedding is independent of this signaling pathway. Here, we used human neuroblastoma SH-SY5Y cells to investigate the involvement of protein kinase C (PKC) in the proteolytic processing of endogenously expressed members of the APP family. Processing was induced by IGF-1 or retinoic acid, another known stimulator of APP α-secretase shedding. Our results show that stimulation of APP and APLP1 processing involves multiple signaling pathways, whereas APLP2 processing is mainly dependent on PKC. Next, we wanted to investigate whether the difference in the regulation of APLP2 shedding compared with APP shedding could be due to involvement of different processing enzymes. We focused on the two major α-secretase candidates ADAM10 and TACE, which both are members of the ADAM (a disintegrin and metalloprotease) family. Shedding was analyzed in the presence of the ADAM10 inhibitor GI254023X, or after transfection with small interfering RNAs targeted against TACE. The results clearly demonstrate that different α-secretases are involved in IGF-1-induced processing. APP is mainly cleaved by ADAM10, whereas APLP2 processing is mediated by TACE. Finally, we also show that IGF-1 induces PKC-dependent phosphorylation of TACE. PMID:20139073

  3. A growth stimulus is needed for IGF-1 to induce skeletal muscle hypertrophy in vivo.

    PubMed

    Shavlakadze, Thea; Chai, Jinfen; Maley, Kirsten; Cozens, Greg; Grounds, Griffin; Winn, Nadine; Rosenthal, Nadia; Grounds, Miranda D

    2010-03-15

    Here, we characterise new strains of normal and dystrophic (mdx) mice that overexpress Class 2 IGF-1 Ea in skeletal myofibres. We show that transgenic mice have increased muscle levels of IGF-1 (approximately 13-26 fold) and show striking muscle hypertrophy (approximately 24-56% increase in mass). Adult normal muscles were resistant to elevated IGF-1; they reached adult steady state and maintained the same mass from 3 to 12 months. By contrast, dystrophic muscles from mdx/IGF-1(C2:Ea) mice continued to increase in mass during adulthood. IGF-1 signalling was evident only in muscles that were growing as a result of normal postnatal development (23-day-old mice) or regenerating in response to endogenous necrosis (adult mdx mice). Increased phosphorylation of Akt at Ser473 was not evident in fasted normal adult transgenic muscles, but was 1.9-fold higher in fasted normal young transgenic muscles compared with age-matched wild-type controls and fourfold higher in fasted adult mdx/IGF-1(C2:Ea) compared with mdx muscles. Muscles of adult mdx/IGF-1(C2:Ea) mice showed higher p70(S6K)(Thr421/Ser424) phosphorylation and both young transgenic and adult mdx/IGF-1(C2:Ea) mice had higher phosphorylation of rpS6(Ser235/236). The level of mRNA encoding myogenin was increased in normal young (but not adult) transgenic muscles, indicating enhanced myogenic differentiation. These data demonstrate that elevated IGF-1 has a hypertrophic effect on skeletal muscle only in growth situations.

  4. Type II SOCS as a feedback repressor for GH-induced Igf1 expression in carp hepatocytes.

    PubMed

    Jiang, Xue; Xiao, Jia; He, Mulan; Ma, Ani; Wong, Anderson O L

    2016-05-01

    Type II suppressor of cytokine signaling (SOCS) serve as feedback repressors for cytokines and are known to inhibit growth hormone (GH) actions. However, direct evidence for SOCS modulation of GH-induced insulin-like growth factor 1 (Igf1) expression is lacking, and the post-receptor signaling for SOCS expression at the hepatic level is still unclear. To shed light on the comparative aspects of SOCS in GH functions, grass carp was used as a model to study the role of type II SOCS in GH-induced Igf1 expression. Structural identity of type II SOCS, Socs1-3 and cytokine-inducible SH2-containing protein (Cish), was established in grass carp by 5'/3'-RACE, and their expression at both transcript and protein levels were confirmed in the liver by RT-PCR and LC/MS/MS respectively. In carp hepatocytes, GH treatment induced rapid phosphorylation of JAK2, STATs, MAPK, PI3K, and protein kinase B (Akt) with parallel rises in socs1-3 and cish mRNA levels, and these stimulatory effects on type II SOCS were shown to occur before the gradual loss of igf1 gene expression caused by prolonged exposure of GH. Furthermore, GH-induced type II SOCS gene expression could be negated by inhibiting JAK2, STATs, MEK1/2, P38 (MAPK), PI3K, and/or Akt respectively. In CHO cells transfected with carp GH receptor, over-expression of these newly cloned type II SOCS not only suppressed JAK2/STAT5 signaling with GH treatment but also inhibited GH-induced grass carp Igf1 promoter activity. These results, taken together, suggest that type II SOCS could be induced by GH in the carp liver via JAK2/STATs, MAPK, and PI3K/Akt cascades and serve as feedback repressors for GH signaling and induction of igf1 gene expression.

  5. IGF-1-Involved Negative Feedback of NR2B NMDA Subunits Protects Cultured Hippocampal Neurons Against NMDA-Induced Excitotoxicity.

    PubMed

    Li, Yun; Sun, Wei; Han, Song; Li, Jianing; Ding, Shu; Wang, Wei; Yin, Yanling

    2017-01-01

    Insulin-like growth factor 1 (IGF-1) is a multifunctional protein involved in neuronal polarity and axonal guidance. In our previous study, it was discovered that IGF-1 alleviated 50-μM NMDA-induced excitotoxicity against neuronal autophagy via depression of NR2B p-Ser1303 activation. However, it was found that NMDA at a higher dose did not cause neuronal autophagy. And, the performance of IGF-1 under severe excitotoxicity still needs to be clarified. In this study, we observed that IGF-1 can salvage the hippocampal neurons in an autophagy-independent manner after 150-μM NMDA exposure using thiazolyl blue tetrazolium bromide (MTT), lactate dehydrogenase (LDH), Western blot assay, and transmission electron microscopy. In addition, over-activation of post-synaptic NMDARs was found with the whole-cell patch clamp recording method. In order to explore whether there is a positive feedback way for post-synaptic NMDARs and the different pathway caused by 150 μM NMDA, the phosphorylation level of Fyn and the phosphorylation site of NR2B were investigated. It was observed that NR2B p-Tyr1472 was increased by the activation of Fyn after 150-μM NMDA exposure. When the neutralizing antibody against NR2B p-Ser1303 was added into the medium, both the activations of Fyn and NR2B p-Tyr1472 were blocked, suggesting NR2B p-Ser1303 may be the initial step of NMDA-induced excitotoxicity. In addition, since IGF-1 can block the initial step of NR2B activation, its effect is concluded to continue with the development of excitotoxicity. Overall, this study strongly indicates that the relationship between different phosphorylation sites of NR2B should be laid more emphasis on, which may be a vital target for the NR2B-involved excitotoxicity.

  6. Safety, pharmacokinetics, and preliminary assessment of efficacy of mecasermin (recombinant human IGF-1) for the treatment of Rett syndrome

    PubMed Central

    Khwaja, Omar S.; Ho, Eugenia; Barnes, Katherine V.; O’Leary, Heather M.; Pereira, Luis M.; Finkelstein, Yaron; Nelson, Charles A.; Vogel-Farley, Vanessa; DeGregorio, Geneva; Holm, Ingrid A.; Khatwa, Umakanth; Kapur, Kush; Alexander, Mark E.; Finnegan, Deirdre M.; Cantwell, Nicole G.; Walco, Alexandra C.; Rappaport, Leonard; Gregas, Matt; Fichorova, Raina N.; Shannon, Michael W.; Sur, Mriganka; Kaufmann, Walter E.

    2014-01-01

    Rett syndrome (RTT) is a severe X-linked neurodevelopmental disorder mainly affecting females and is associated with mutations in MECP2, the gene encoding methyl CpG-binding protein 2. Mouse models suggest that recombinant human insulin-like growth factor 1 (IGF-1) (rhIGF1) (mecasermin) may improve many clinical features. We evaluated the safety, tolerability, and pharmacokinetic profiles of IGF-1 in 12 girls with MECP2 mutations (9 with RTT). In addition, we performed a preliminary assessment of efficacy using automated cardiorespiratory measures, EEG, a set of RTT-oriented clinical assessments, and two standardized behavioral questionnaires. This phase 1 trial included a 4-wk multiple ascending dose (MAD) (40–120 μg/kg twice daily) period and a 20-wk open-label extension (OLE) at the maximum dose. Twelve subjects completed the MAD and 10 the entire study, without evidence of hypoglycemia or serious adverse events. Mecasermin reached the CNS compartment as evidenced by the increase in cerebrospinal fluid IGF-1 levels at the end of the MAD. The drug followed nonlinear kinetics, with greater distribution in the peripheral compartment. Cardiorespiratory measures showed that apnea improved during the OLE. Some neurobehavioral parameters, specifically measures of anxiety and mood also improved during the OLE. These improvements in mood and anxiety scores were supported by reversal of right frontal alpha band asymmetry on EEG, an index of anxiety and depression. Our data indicate that IGF-1 is safe and well tolerated in girls with RTT and, as demonstrated in preclinical studies, ameliorates certain breathing and behavioral abnormalities. PMID:24623853

  7. IGF-1 Signaling Plays an Important Role in the Formation of Three-Dimensional Laminated Neural Retina and Other Ocular Structures From Human Embryonic Stem Cells.

    PubMed

    Mellough, Carla B; Collin, Joseph; Khazim, Mahmoud; White, Kathryn; Sernagor, Evelyne; Steel, David H W; Lako, Majlinda

    2015-08-01

    We and others have previously demonstrated that retinal cells can be derived from human embryonic stem cells (hESCs) and induced pluripotent stem cells under defined culture conditions. While both cell types can give rise to retinal derivatives in the absence of inductive cues, this requires extended culture periods and gives lower overall yield. Further understanding of this innate differentiation ability, the identification of key factors that drive the differentiation process, and the development of clinically compatible culture conditions to reproducibly generate functional neural retina is an important goal for clinical cell based therapies. We now report that insulin-like growth factor 1 (IGF-1) can orchestrate the formation of three-dimensional ocular-like structures from hESCs which, in addition to retinal pigmented epithelium and neural retina, also contain primitive lens and corneal-like structures. Inhibition of IGF-1 receptor signaling significantly reduces the formation of optic vesicle and optic cups, while exogenous IGF-1 treatment enhances the formation of correctly laminated retinal tissue composed of multiple retinal phenotypes that is reminiscent of the developing vertebrate retina. Most importantly, hESC-derived photoreceptors exhibit advanced maturation features such as the presence of primitive rod- and cone-like photoreceptor inner and outer segments and phototransduction-related functional responses as early as 6.5 weeks of differentiation, making these derivatives promising candidates for cell replacement studies and in vitro disease modeling.

  8. Gamma-hydroxybutyrate (GHB) induces cognitive deficits and affects GABAB receptors and IGF-1 receptors in male rats.

    PubMed

    Johansson, Jenny; Grönbladh, Alfhild; Hallberg, Mathias

    2014-08-01

    In recent years, the abuse of the club drug gamma-hydroxybutyrate (GHB) has become increasingly popular among adolescents. The drug induces euphoria but can also result in sedation, anaesthesia as well as short-term amnesia. In addition, the abuse of GHB causes cognitive impairments and the mechanism by which GHB induces these impairments is not clarified. The present study investigates the impact of GHB treatment on spatial learning and memory using a water maze (WM) test in rats. Furthermore, the behavioural data is combined with an autoradiographic analysis of the GABAB and the IGF-1 receptor systems. The results demonstrate that the animals administered with GHB display an impaired performance in the WM test as compared to controls. In addition, significant alterations in GABAB and IGF-1 receptor density as well as GABAB receptor functionality, were observed in several brain regions associated with cognitive functions e.g. hippocampus. To conclude, our findings suggest that GHB treatment can affect spatial learning and memory, and that this outcome at least to some extent is likely to involve both GABAB and IGF-1 receptors.

  9. Skeletal muscle plasticity induced by seasonal acclimatization involves IGF1 signaling: implications in ribosomal biogenesis and protein synthesis.

    PubMed

    Fuentes, Eduardo N; Zuloaga, Rodrigo; Valdes, Juan Antonio; Molina, Alfredo; Alvarez, Marco

    2014-10-01

    One of the most fundamental biological processes in living organisms that are affected by environmental fluctuations is growth. In fish, skeletal muscle accounts for the largest proportion of body mass, and the growth of this tissue is mainly controlled by the insulin-like growth factor (IGF) system. By using the carp (Cyprinus carpio), a fish that inhabits extreme conditions during winter and summer, we assessed the skeletal muscle plasticity induced by seasonal acclimatization and the relation of IGF signaling with protein synthesis and ribosomal biogenesis. The expression of igf1 in muscle decreased during winter in comparison with summer, whereas the expression for both paralogues of igf2 did not change significantly between seasons. The expression of igf1 receptor a (igf1ra), but not of igf1rb, was down-regulated in muscle during the winter as compared to the summer. A decrease in protein contents and protein phosphorylation for IGF signaling molecules in muscle was observed in winter-acclimatized carp. This was related with a decreased expression in muscle for markers of myogenesis (myoblast determination factor (myod), myogenic factor 5 (myf5), and myogenin (myog)); protein synthesis (myosin heavy chain (mhc) and myosin light chain (mlc3 and mlc1b)); and ribosomal biogenesis (pre-rRNA and ribosomal proteins). IGF signaling, and key markers of ribosomal biogenesis, protein synthesis, and myogenesis were affected by seasonal acclimatization, with differential regulation in gene expression and signaling pathway activation observed in muscle between both seasons. This suggests that these molecules are responsible for the muscle plasticity induced by seasonal acclimatization in carp.

  10. Prolactin, Androstenedione and IGF1 Serum Concentrations During Induced Follicular Growth by eCG Administration in the Bitch.

    PubMed

    Stornelli, M C; García Mitacek, M C; Praderio, R G; Nuñez Favre, R; de la Sota, R L; Stornelli, M A

    2016-02-01

    The oestrus cycle in the domestic bitch, a monoestrous species, differs considerably from that of other veterinary domestic animals species. In the bitch the combined use of eCG and hCG is effective to induce oestrus predictably and safely (Stornelli et al., Theriogenology, 78, 2012 and 1056). Although several studies were done to describe the hormonal changes during the canine oestrus cycle, to our knowledge none was done to describe the hormonal changes during induced follicular growth after the administration of eCG. The aim of this work was to study prolactin (PRL), insulin-like growth factor (IGF1) and androstenedione (ANDR) serum concentrations during follicular growth induced by a single dose of eCG administered to late anoestrous bitches. PRL and ANDR concentrations were lower before than after eCG TRT (before eCG vs pro-oestrus, oestrus and dioestrus; 4.3 ± 1.8 ng/ml vs 6.5 ± 1.6 ng/ml, p < 0.05; 0.08 ± 0.2 ng/ml vs 0.42 ± 0.16 ng/ml, p < 0.05). Conversely, IGF1 concentrations were similar before and after eCG TRT (286.0 ng/ml ±32.2, p > 0.53). Additionally, PRL concentrations were similar before oestrus compared to during oestrus and dioestrus (6.9 ± 1.7 ng/ml, p > 0.19). Furthermore, IGF1 concentrations were higher before and during oestrus compared to first day of dioestrus (286.1 ± 29.8vs 200.4 ± 29.2 ng/ml, p < 0.01). On the contrary, ANDR concentrations were lower before and during oestrus compared to first day of diestrum (0.35 ± 0.17 ng/ml and 0.38 ± 0.15 vs 0.68 ± 0.17 ng/ml, p < 0.05). These results show that treatment with a single injection of 50 IU/kg of eCG in late anoestrous bitches successfully induced changes in follicular growth which were paralleled with changes in PRL, IGF1 and ANDR serum concentration similar to those occurring during a normally occurring oestrous cycle. In addition, our results suggest that IGF1 in the bitch could play an important role in ovarian folliculogenesis.

  11. Angelica Sinensis Polysaccharides Stimulated UDP-Sugar Synthase Genes through Promoting Gene Expression of IGF-1 and IGF1R in Chondrocytes: Promoting Anti-Osteoarthritic Activity

    PubMed Central

    Wen, Yinxian; Li, Jing; Tan, Yang; Qin, Jun; Xie, Xianfei; Wang, Linlong; Mei, Qibing; Wang, Hui; Magdalou, Jacques; Chen, Liaobin

    2014-01-01

    Background Osteoarthritis (OA) is a chronic joints disease characterized by progressive degeneration of articular cartilage due to the loss of cartilage matrix. Previously, we found, for the first time, that an acidic glycan from Angelica Sinensis Polysaccharides (APSs), namely the APS-3c, could protect rat cartilage from OA due to promoting glycosaminoglycan (GAG) synthesis in chondrocytes. In the present work, we tried to further the understanding of ASP-3c’s anti-OA activity. Methodology/Principal Findings Human primary chondrocytes were treated with APS-3c or/and recombinant human interleukin 1β (IL-1β). It turned out that APS-3c promoted synthesis of UDP-xylose and GAG, as well as the gene expression of UDP-sugar synthases (USSs), insulin like growth factor 1 (IGF1) and IGF1 receptor (IGF1R), and attenuated the degenerative phenotypes, suppressed biosynthesis of UDP-sugars and GAG, and inhibited the gene expression of USSs, IGF1 and IGF1R induced by IL-1β. Then, we induced a rat OA model with papain, and found that APS-3c also stimulated GAG synthesis and gene expression of USSs, IGF1 and IGF1R in vivo. Additionally, recombinant human IGF1 and IGF1R inhibitor NP-AEW541 were applied to figure out the correlation between stimulated gene expression of USSs, IGF1 and IGF1R induced by APS-3c. It tuned out that the promoted GAG synthesis and USSs gene expression induced by APS-3c was mediated by the stimulated IGF1 and IGF1R gene expression, but not through directly activation of IGF1R signaling pathway. Conclusions/Significances We demonstrated for the first time that APS-3c presented anti-OA activity through stimulating IGF-1 and IGF1R gene expression, but not directly activating the IGF1R signaling pathway, which consequently promoted UDP-sugars and GAG synthesis due to up-regulating gene expression of USSs. Our findings presented a better understanding of APS-3c’s anti-OA activity and suggested that APS-3c could potentially be a novel therapeutic agent

  12. Systemic delivery of human mesenchymal stromal cells combined with IGF-1 enhances muscle functional recovery in LAMA2 dy/2j dystrophic mice.

    PubMed

    Secco, Mariane; Bueno, Carlos; Vieira, Natassia M; Almeida, Camila; Pelatti, Mayra; Zucconi, Eder; Bartolini, Paolo; Vainzof, Mariz; Miyabara, Elen H; Okamoto, Oswaldo K; Zatz, Mayana

    2013-02-01

    The combination of cell therapy with growth factors could be a useful approach to treat progressive muscular dystrophies. Here, we demonstrate, for the first time, that IGF-1 considerably enhances the myogenesis of human umbilical cord (UC) mesenchymal stromal cells (MSCs) in vitro and that IGF-1 enhances interaction and restoration of dystrophin expression in co-cultures of MSCs and muscle cells from Duchenne patients. In vivo studies showed that human MSCs were able to reach the skeletal muscle of LAMA2(dy/2j) dystrophic mice, through systemic delivery, without immunosuppression. Moreover, we showed, for the first time, that IGF-1 injected systemically together with MSCs markedly reduced muscle inflammation and fibrosis, and significantly improved muscle strength in dystrophic mice. Our results suggest that a combined treatment with IGF-1 and MSCs enhances efficiency of muscle repair and, therefore, should be further considered as a potential therapeutic approach in muscular dystrophies.

  13. N-Acetylcysteine in Combination with IGF-1 Enhances Neuroprotection against Proteasome Dysfunction-Induced Neurotoxicity in SH-SY5Y Cells

    PubMed Central

    Anand, Pinki; Kuang, Anxiu; Akhtar, Feroz; Scofield, Virginia L.

    2016-01-01

    Ubiquitin proteasome system (UPS) dysfunction has been implicated in the development of many neuronal disorders, including Parkinson's disease (PD). Previous studies focused on individual neuroprotective agents and their respective abilities to prevent neurotoxicity following a variety of toxic insults. However, the effects of the antioxidant N-acetylcysteine (NAC) on proteasome impairment-induced apoptosis have not been well characterized in human neuronal cells. The aim of this study was to determine whether cotreatment of NAC and insulin-like growth factor-1 (IGF-1) efficiently protected against proteasome inhibitor-induced cytotoxicity in SH-SY5Y cells. Our results demonstrate that the proteasome inhibitor, MG132, initiates poly(ADP-ribose) polymerase (PARP) cleavage, caspase 3 activation, and nuclear condensation and fragmentation. In addition, MG132 treatment leads to endoplasmic reticulum (ER) stress and autophagy-mediated cell death. All of these events can be attenuated without obvious reduction of MG132 induced protein ubiquitination by first treating the cells with NAC and IGF-1 separately or simultaneously prior to exposure to MG132. Moreover, our data demonstrated that the combination of the two proved to be significantly more effective for neuronal protection. Therefore, we conclude that the simultaneous use of growth/neurotrophic factors and a free radical scavenger may increase overall protection against UPS dysfunction-mediated cytotoxicity and neurodegeneration. PMID:27774335

  14. IGF-1 and insulin as growth hormones.

    PubMed

    Laron, Zvi

    2004-01-01

    IGF-1 generated in the liver is the anabolic effector and linear growth promoting hormone of the pituitary growth hormone (GH). This is evidenced by dwarfism in states of congenital IGF-1 deficiency, Igf1 gene mutation/deletions or knockouts, and in Laron syndrome (LS), due to GH receptor gene mutations/deletions or IGF-1 receptor blocking. In a positive way, daily IGF-1 administration to stunted patients with LS or hGH gene deletion accelerates linear growth velocity. IGF-1 acts on the proliferative cells of the epiphyseal cartilage. IGF-1 also induces organ and tissue growth; its absence causing organomicria. Insulin shares a common ancestry with IGF-1 and with 45% amino acid homology, as well as very close relationships in the structure of its receptors and post-receptor cascade, also acts as a growth hormone. It has protein anabolic activity and stimulates IGF-1 synthesis. Pancreas agenesis causes short babies, and obese children with hyperinsulinism, with or without pituitary GH, have an accelerated growth rate and skeletal maturation; so do babies with macrosomia. Whether the insulin growth effect is direct, or mediated by IGF-1 or leptin is controversial.

  15. IGF-1 increases invasive potential of MCF 7 breast cancer cells and induces activation of latent TGF-β1 resulting in epithelial to mesenchymal transition

    PubMed Central

    2011-01-01

    Introduction TGF-β signaling has been extensively studied in many developmental contexts, amongst which is its ability to induce epithelial to mesenchymal transitions (EMT). EMTs play crucial roles during embryonic development and have also come under intense scrutiny as a mechanism through which breast cancers progress to become metastatic. Interestingly, while the molecular hallmarks of EMT progression (loss of cell adhesion, nuclear localization of β-catenin) are straightforward, the cellular signaling cascades that result in an EMT are numerous and diverse. Furthermore, most studies describing the biological effects of TGF-β have been performed using high concentrations of active, soluble TGF-β, despite the fact that TGF-β is produced and secreted as a latent complex. Methods MCF-7 breast cancer cells treated with recombinant IGF-1 were assayed for metalloproteinase activity and invasiveness through a matrigel coated transwell invasion chamber. IGF-1 treatments were then followed by the addition of latent-TGF-β1 to determine if elevated levels of IGF-1 together with latent-TGF-β1 could cause EMT. Results Results showed that IGF-1 - a molecule known to be elevated in breast cancer is a regulator of matrix metalloproteinase activity (MMP) and the invasive potential of MCF-7 breast cancer cells. The effects of IGF-1 appear to be mediated through signals transduced via the PI3K and MAPK pathways. In addition, increased IGF-1, together with latent TGF-β1 and active MMPs result in EMT. Conclusions Taken together our data suggest a novel a link between IGF-1 levels, MMP activity, TGF-β signaling, and EMT in breast cancer cells. PMID:21535875

  16. Human Eb Peptide: Not just a By-product of Pre-pro-IGF1b Processing?

    PubMed Central

    Durzyńska, J.; Wardziński, A.; Koczorowska, M.; Goździcka-Józefiak, A.; Barton, E. R.

    2015-01-01

    Several physiological activities have been assigned to E-peptides derived from pre-pro-insulin-like growth factor (IGF1) processing; however, the whole range of the E-peptides’ functions is still unknown. The objective of this study was to investigate human Eb peptide (hEb) in terms of its bioactivity, cellular localization, and intracellular trafficking using human cancer cells. Human Eb fused with red fluorescence protein (RFP) or green fluorescence protein (GFP) localizes strongly to nucleoli and to a lesser extent to nuclei of HeLa and U2-OS cells. Mutagenesis of hEb nucleolus localization sequence (NoLS) leads to its partial delocalization from nuclei and nucleoli to cytoplasm of transfected cells. Thus, NoLS is not sufficient for the hEb to be localized in nucleoli of the cells and a different mechanism may be involved in hEb targeting. A BrdU ELISA showed that the proliferation index of cells expressing hEb hybrid proteins increased up to 28 %. For comparison, the same assay was performed using HeLa cells treated extracellularly with synthetic hEb. A significant increase in the proliferation index was observed (41–58 % for concentrations ranging from 10–100 nM, respectively). Additionally, a cell migration assay was performed using stable U2-OS cell lines expressing hEb fused with RFP or RFP alone as a negative control. The migration index of hEb expressing cells was 38.3 % greater. The increase in cell proliferation index and in motile properties of hEb expressing cells demonstrate that hEb is more than a pre-pro-IGF1b processing product, and has intrinsic activity of biological significance. PMID:23335048

  17. Evaluation of a novel hexavalent humanized anti-IGF-1R antibody and its bivalent parental IgG in diverse cancer cell lines.

    PubMed

    Chang, Chien-Hsing; Wang, Yang; Trisal, Preeti; Li, Rongxiu; Rossi, Diane L; Nair, Anju; Gupta, Pankaj; Losman, Michele; Cardillo, Thomas M; Rossi, Edmund A; Goldenberg, David M

    2012-01-01

    A major mechanism of monoclonal antibodies that selectively target the insulin-like growth factor type 1 receptor (IGF-1R) to inhibit tumor growth is by downregulating the receptor, regardless whether they are capable (antagonistic) or incapable (agonistic) of blocking the binding of cognate ligands. We have developed and characterized a novel agonistic anti-IGF-1R humanized antibody, hR1, and used the Dock-and-Lock (DNL) method to construct Hex-hR1, the first multivalent antibody comprising 6 functional Fabs of hR1, with the aim of enhancing potency of hR1. Based on cross-blocking experiments, hR1 recognizes a region of cysteine-rich domain on the α-subunit, different from the epitopes mapped for existing anti-IGF-1R antibodies, yet hR1 is similar to other anti-IGF-1R antibodies in downregulating IGF-1R and inhibiting proliferation, colony formation, or invasion of selected cancer cell lines in vitro, as well as suppressing growth of the RH-30 rhabdomyosarcoma xenograft in nude mice when combined with the mTOR inhibitor, rapamycin. Hex-hR1 and hR1 are generally comparable in their bioactivities under the in-intro and in-vivo conditions investigated. Nevertheless, in selective experiments involving a direct comparison of potency, Hex-hR1 demonstrated a stronger effect on inhibiting cell proliferation stimulated by IGF-1 and could effectively downregulate IGF-1R at a concentration as low as 20 pM.

  18. Delayed IGF-1 treatment reduced long-term hypoxia-ischemia-induced brain damage and improved behavior recovery of immature rats.

    PubMed

    Zhong, Jin; Zhao, Limin; Du, Yansheng; Wei, Gang; Yao, Wei-Guo; Lee, Wei-Hua

    2009-06-01

    Cerebral hypoxia-ischemia during the perinatal period is the single most important cause of acute newborn mortality and chronic disability. Despite our increasing understanding of the mechanisms of neuronal injury, an effective clinical therapy has yet to be established to mitigate brain damage and improve the prognosis and well-being of these newborn patients. Insulin-like growth factor 1 (IGF-1) is a well-known neurotrophic factor, essential for the survival and functional maturation of immature neurons. This study demonstrated that subcutaneous administration of IGF-1 at 24 and 48 hours of recovery significantly reduced hypoxia-ischemia-induced injury to immature rat brains and improved long-term memory and cognitive behavior. IGF-1's therapeutic effects likely involve its ability to prevent delayed apoptosis, as we demonstrated in primary cortical neuronal cultures under oxygen and glucose deprivation. IGF-1's neuroprotective effects parallel the activities of phosphatidylinositol-3/Akt and its down-stream signaling pathway, suggesting a potential mechanistic link. Overall, evidence from this investigation strongly supports IGF-1's potential therapeutic use in the treatment of hypoxic-ischemic encephalopathy in newborn patients.

  19. Binding of anterior gradient 2 and estrogen receptor-α: Dual critical roles in enhancing fulvestrant resistance and IGF-1-induced tumorigenesis of breast cancer.

    PubMed

    Li, Zheqi; Zhu, Qi; Chen, Hao; Hu, Lingyun; Negi, Hema; Zheng, Yun; Ahmed, Yeasin; Wu, Zhenghua; Li, Dawei

    2016-07-10

    Anterior gradient 2 (AGR2), an essential cancer biomarker, has been widely reported to be associated with estrogen receptor (ER) positive breast cancer development. Here, we uncovered the role of cytoplasmic and exogenous AGR2, through interaction with ER-α, in enhancing fulvestrant resistance and IGF-1-induced carcinogenesis respectively. Our present study revealed that the endogenous AGR2 level positively correlates with fulvestrant resistance in MCF-7 and T47D cells. AGR2-knockdown in MCF-7 cells strongly enhances the fulvestrant-induced G1 phase arrest and accelerates the fulvestrant-induced ER-α degradation. Furthermore, intracellular AGR2 exhibits a functional interaction with ER-α. On the other hand, extracellular AGR2 remarkably promotes the IGF-1-induced cell proliferation, migration, cell cycle progression and epithelial-mesenchymal transition. Extracellular AGR2 also enhances IGF-1 downstream signaling. We also showed that ER-α specifically interacts with both extracellular AGR2 and IGF-1 receptor as a potential intermediator. Finally, we revealed that the adjuvant therapy of AGR2 monoclonal antibody enhances the inhibitory effects of fulvestrant and linsitinib toward breast cancer development. Our findings, for the first time, point out the different functions of intra- and extra-cellular AGR2, providing new insights into the development of anti-tumor therapies targeting AGR2.

  20. Quantitative Phosphoproteomics Analysis Reveals a Key Role of Insulin Growth Factor 1 Receptor (IGF1R) Tyrosine Kinase in Human Sperm Capacitation*

    PubMed Central

    Wang, Jing; Qi, Lin; Huang, Shaoping; Zhou, Tao; Guo, Yueshuai; Wang, Gaigai; Guo, Xuejiang; Zhou, Zuomin; Sha, Jiahao

    2015-01-01

    One of the most important changes during sperm capacitation is the enhancement of tyrosine phosphorylation. However, the mechanisms of protein tyrosine phosphorylation during sperm capacitation are not well studied. We used label-free quantitative phosphoproteomics to investigate the overall phosphorylation events during sperm capacitation in humans and identified 231 sites with increased phosphorylation levels. Motif analysis using the NetworKIN algorithm revealed that the activity of tyrosine phosphorylation kinases insulin growth factor 1 receptor (IGF1R)/insulin receptor is significantly enriched among the up-regulated phosphorylation substrates during capacitation. Western blotting further confirmed inhibition of IGF1R with inhibitors GSK1904529A and NVP-AEW541, which inhibited the increase in tyrosine phosphorylation levels during sperm capacitation. Additionally, sperm hyperactivated motility was also inhibited by GSK1904529A and NVP-AEW541 but could be up-regulated by insulin growth factor 1, the ligand of IGF1R. Thus, the IGF1R-mediated tyrosine phosphorylation pathway may play important roles in the regulation of sperm capacitation in humans and could be a target for improvement in sperm functions in infertile men. PMID:25693802

  1. Involvement of IGF-2, IGF-1R, IGF-2R and PTEN in development of human tooth germ - an immunohistochemical study.

    PubMed

    Kero, Darko; Cigic, Livia; Medvedec Mikic, Ivana; Galic, Tea; Cubela, Mladen; Vukojevic, Katarina; Saraga-Babic, Mirna

    2016-07-02

    Insulin-Like Growth Factor 2 (IGF-2) is a peptide hormone essential for prenatal growth and development. IGF-2 exerts its mitogenic effects via Insulin-Like Growth Factor 1 Receptor (IGF-1R), and is eliminated by binding to Insulin-Like Growth Receptor 2 (IGF-2R). IGF-2 is also negatively regulated by Phosphatase and Tensin Homolog (PTEN), a phosphatase mutated in various tumors. Not much is known about the interplay between these factors during human odontogenesis. In this study, expression patterns of IGF-2, IGF-1R, IGF-2R and PTEN were analyzed by double immunofluorescence in incisor human tooth germs during the foetal period of development between the 7(th) and 20(th) gestational week. Throughout the investigated period, IGF-2 was mostly expressed in enamel organ, whereas mild to moderate expression of PTEN could be seen in dental papilla and parts of enamel organ. Expression of IGF-1R was ubiquitous and displayed strong intensity throughout the entire enamel organ. In contrast, expression of IGF-2R had rather erratic pattern in enamel organ and dental papilla alike. Expression patterns of IGF-2, IGF-1R, IGF-2R and PTEN in highly proliferative cervical loops, as well as in differentiating pre-ameloblasts and pre-odontoblasts of cusp tip region during the early and late bell stages when enamel organ acquires definitive shape, indicate importance of these factors in crown morphogenesis of human incisor. Taken together, our data suggest the involvement of IGF-2, IGF-1R, IGF-2R and PTEN in temporo-spatial patterning of basic cellular processes (proliferation, differentiation) during normal tooth development. They are also relevant for improving knowledge of molecular basis of human odontogenesis.

  2. VHL-deficient renal cancer cells gain resistance to mitochondria-activating apoptosis inducers by activating AKT through the IGF1R-PI3K pathway.

    PubMed

    Yamaguchi, Ryuji; Harada, Hiroshi; Hirota, Kiichi

    2016-10-01

    We previously developed (2-deoxyglucose)-(ABT-263) combination therapy (2DG-ABT), which induces apoptosis by activating Bak in the mitochondria of highly glycolytic cells with varied genetic backgrounds. However, the rates of apoptosis induced by 2DG-ABT were lower in von Hippel-Lindau (VHL)-deficient cancer cells. The re-expression of VHL protein in these cells lowered IGF1R expression in a manner independent of oxygen concentration. Lowering IGF1R expression via small interfering RNA (siRNA) sensitized the cells to 2DG-ABT, suggesting that IGF1R interfered with the activation of apoptosis by the mitochondria. To determine which of the two pathways activated by IGF1R, the Ras-ERK pathway or the PI3K-AKT pathway, was involved in the impairment of mitochondria activation, the cells were treated with a specific inhibitor of either PI3K or ERK, and 2DG-ABT was added to activate the mitochondria. The apoptotic rates resulting from 2DG-ABT treatment were higher in the cells treated with the PI3K inhibitor, while the rates remained approximately the same in the cells treated with the ERK inhibitor. In 2DG-ABT-sensitive cells, a 4-h 2DG treatment caused the dissociation of Mcl-1 from Bak, while ABT treatment alone caused the dissociation of Bcl-xL from Bak without substantially reducing Mcl-1 levels. In 2DG-ABT-resistant cells, Mcl-1 dissociated from Bak only when AKT activity was inhibited during the 4-h 2DG treatment. Thus, in VHL-deficient cells, IGF1R activated AKT and stabilized the Bak-Mcl-1 complex, thereby conferring cell resistance to apoptosis.

  3. IGF-1 induces IP3 -dependent calcium signal involved in the regulation of myostatin gene expression mediated by NFAT during myoblast differentiation.

    PubMed

    Valdés, Juan A; Flores, Sylvia; Fuentes, Eduardo N; Osorio-Fuentealba, Cesar; Jaimovich, Enrique; Molina, Alfredo

    2013-07-01

    Skeletal muscle differentiation is a complex and highly regulated process characterized by cell cycle arrest, which is associated with morphological changes including myoblast alignment, elongation, and fusion into multinucleated myotubes. This is a balanced process dynamically coordinated by positive and negative signals such as the insulin-like growth factor I (IGF-1) and myostatin (MSTN), respectively. In this study, we report that the stimulation of skeletal myoblasts during differentiation with IGF-1 induces a rapid and transient calcium increase from intracellular stores, which are principally mediated through the phospholipase C gamma (PLC γ)/inositol 1,4,5-triphosphate (IP3 )-dependent signaling pathways. This response was completely blocked when myoblasts were incubated with LY294002 or transfected with the dominant-negative p110 gamma, suggesting a fundamental role of phosphatidylinositol 3-kinase (PI3K) in PLCγ activation. Additionally, we show that calcium released via IP3 and induced by IGF-1 stimulates NFAT-dependent gene transcription and nuclear translocation of the GFP-labeled NFATc3 isoform. This activation was independent of extracellular calcium influx and calcium release mediated by ryanodine receptor (RyR). Finally, we examined mstn mRNA levels and mstn promoter activity in myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents and in reporter activity, which was inhibited by cyclosporin A, 11R-VIVIT, and by inhibitors of the PI3Kγ, PLCγ, and IP3 receptor. Our results strongly suggest that IGF-1 regulates myostatin transcription through the activation of the NFAT transcription factor in an IP3 /calcium-dependent manner. This is the first study to demonstrate a role of calcium-dependent signaling pathways in the mRNA expression of myostatin.

  4. Effects of recombinant human growth hormone in the treatment of dwarfism and relationship between IGF-1, IGFBP-3 and thyroid hormone

    PubMed Central

    Ren, Shanxiang; Nie, Yuxiang; Wang, Aihong

    2016-01-01

    The effects of recombinant human growth hormone (rhGH) in the treatment of dwarfism and the relationship between insulin-like growth factor (IGF)-1, IGF-binding protein (IGFBP)-3 and thyroid hormone were examined in the present study. For this purpose, 66 patients diagnosed with dwarfism were selected retrospectively, with 36 cases of growth hormone deficiency (GHD) and 30 cases of idiopathic short stature (ISS). The therapeutic dose of GHD 0.10 IU/kg·day and ISS 0.15 IU/kg·day were injected subcutaneously every night before sleep until adulthood. The average follow-up was 5 years, and the results were evaluated and measured every 3 months, including height, BA, secondary test of growth hormone (GH peak), IGF-1, IGFBP-3 and thyroid hormone (FT3, FT4 and TSH). After treatment, the height, BA, GH peak, IGF-A and IGFBP-3 of the GHD group were all increased, and the differences were statistically significant (P<0.05), while FT3, FT4 and TSH had no significant change (P<0.05). The height and BA increased and the differences were statistically significant (P<0.05). The indexes of the ISS group were not statistically significant (P>0.05). The results of the Pearson-related analysis suggested that GH peak of the GHD group, IGF-1 and IGFBP-3 were positively associated with height (P<0.05), and had no relationship with BA (P<0.05). None of the above indexes of the ISS group had an obvious correlation with height and BA (P>0.05). rhGH was effective for GHD and ISS, with the GHD effect being positively associated with the GH peak, IGF-1 and IGFBP-3. ISS had no obvious relationship with GH peak, IGF-1 and IGFBP-3 although other influencing factors may be involved. PMID:28105090

  5. Molecular IGF-1 and IGF-1 receptor defects: from genetics to clinical management.

    PubMed

    Walenkamp, M J E; Losekoot, M; Wit, J M

    2013-01-01

    Molecular defects of the insulin-like growth factor 1 gene (IGF1) are rare in the human. Only three homozygous and two families with heterozygous mutations of the IGF1 gene have been described, resulting in a variable degree of intrauterine and postnatal growth retardation, microcephaly, developmental delay and deafness. Detailed genetic analysis and functional experiments have shown that IGF-1 plays a key role in pre- and postnatal growth and development in human. Eleven patients with heterozygous and 2 patients with compound heterozygous mutations in the type 1 IGF1 receptor gene (IGF1R) have been reported. Intrauterine and postnatal growth retardation, microcephaly and IGF-1 levels above the mean of age references are consistent findings in these patients, although IGF-1 levels can be low initially because of feeding problems. The first reported patients showed the most severe phenotype, but with the identification of additional patients the phenotype appears to be more variable. The functional effect of the defects has been studied by in vitro experiments. From these studies, receptor haploinsufficiency, decreased IGF1R biosynthesis, interference with ligand binding and transmembrane signaling, and disruption of the intrinsic tyrosine kinase activity have been suggested as possible mechanisms with a variable pathogenetic spectrum. Data on GH treatment in these children are limited, showing a poor to modest growth response.

  6. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

    SciTech Connect

    Deng, Yu; Cao, Hong; Cu, Fenglong; Xu, Dan; Lei, Youying; Tan, Yang; Magdalou, Jacques; Wang, Hui; Chen, Liaobin

    2013-05-15

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes.

  7. Role of hormonal axis, growth hormone - IGF-1, in the therapeutic effect of ghrelin in the course of cerulein-induced acute pancreatitis.

    PubMed

    Ceranowicz, D; Warzecha, Z; Dembinski, A; Ceranowicz, P; Cieszkowski, J; Kusnierz-Cabala, B; Tomaszewska, R; Kuwahara, A; Kato, I

    2010-10-01

    Ghrelin is a ligand for growth hormone secretagogue receptor and stimulates release of growth hormone (GH). Recent studies have shown that treatment with ghrelin exhibits protective and therapeutic effect in the course of experimental pancreatitis. The aim of present study was to examine the role of GH and insulin-like growth factor-1 (IGF-1) in these effects. Acute pancreatitis was induced by cerulein. Study was performed on pituitary-intact hypophysectomized rats. Ghrelin was administered twice a day at the dose of 8 nmol/kg/dose. IGF-1 was given twice a day at the dose of 20 nmol/kg/dose. The severity of acute pancreatitis was assessed 0 h or 1, 2, 3, 5 and 10 days after the last dose of cerulein. Administration of cerulein led to the development of acute edematous pancreatitis. In pituitary-intact rats, treatment with ghrelin reduced biochemical indexes of the severity of acute pancreatitis and morphological signs of pancreatic damage, leading to faster regeneration of the pancreas reduction in serum concentration of pro-inflammatory interleukin-1β and decrease in serum activity of amylase and lipase. These effects were accompanied with an improvement of pancreatic blood flow and an increase in pancreatic DNA synthesis. Hypophysectomy delayed the healing of the pancreas and abolished the therapeutic effect of ghrelin. In hypophysectomized rats with pancreatitis, treatment with IGF-1 exhibits therapeutic effect similar to that observed in ghrelin-treated rats with the intact pituitary. We conclude that therapeutic effect of ghrelin in cerulein-induced pancreatitis is indirect and depends on the release of GH and IGF-1.

  8. Upregulation of miR-150* and miR-630 Induces Apoptosis in Pancreatic Cancer Cells by Targeting IGF-1R

    PubMed Central

    Farhana, Lulu; Dawson, Marcia I.; Murshed, Farhan; Das, Jayanta K.; Rishi, Arun K.; Fontana, Joseph A.

    2013-01-01

    MicroRNAs have been implicated in many critical cellular processes including apoptosis. We have previously found that apoptosis in pancreatic cancer cells was induced by adamantyl retinoid-related (ARR) molecule 3-Cl-AHPC. Here we report that 3-Cl-AHPC-dependent apoptosis involves regulating a number of microRNAs including miR-150* and miR-630. 3-Cl-AHPC stimulated miR-150* expression and caused decreased expression of c-Myb and IGF-1R in the pancreatic cancer cells. 3-Cl-AHPC-mediated reduction of c-Myb resulted in diminished binding of c-Myb with IGF-1R and Bcl-2 promoters, thereby causing repression of their transcription and protein expression. Over-expression of miR-150* also resulted in diminished levels of c-Myb and Bcl-2 proteins. Furthermore, the addition of the miRNA inhibitor 2′-O-methylated miR-150 blocked 3-Cl-AHPC-mediated increase in miR-150* levels and abrogated loss of c-Myb protein. Knockdown of c-Myb in PANC-1 cells resulted in enhanced apoptosis both in the presence or absence of 3-Cl-AHPC confirming the anti-apoptotic property of c-Myb. Overexpression of miR-630 also induced apoptosis in the pancreatic cancer cells and inhibited target protein IGF-1R mRNA and protein expression. Together these results implicate key roles for miR-150* and miR-630 and their targeting of IGF-1R to promote apoptosis in pancreatic cancer cells. PMID:23675407

  9. Illness Severity, Social and Cognitive Ability, and EEG Analysis of Ten Patients with Rett Syndrome Treated with Mecasermin (Recombinant Human IGF-1).

    PubMed

    Pini, Giorgio; Congiu, Laura; Benincasa, Alberto; DiMarco, Pietro; Bigoni, Stefania; Dyer, Adam H; Mortimer, Niall; Della-Chiesa, Andrea; O'Leary, Sean; McNamara, Rachel; Mitchell, Kevin J; Gill, Michael; Tropea, Daniela

    2016-01-01

    Rett Syndrome (RTT) is a severe neurodevelopmental disorder characterized by an apparently normal development followed by an arrest and subsequent regression of cognitive and psychomotor abilities. At present, RTT has no definitive cure and the treatment of RTT represents a largely unmet clinical need. Following partial elucidation of the underlying neurobiology of RTT, a new treatment has been proposed, Mecasermin (recombinant human Insulin-Like Growth Factor 1), which, in addition to impressive evidence from preclinical murine models of RTT, has demonstrated safety in human studies of patients with RTT. The present clinical study examines the disease severity as assessed by clinicians (International Scoring System: ISS), social and cognitive ability assessed by two blinded, independent observers (RSS: Rett Severity Score), and changes in brain activity (EEG) parameters of ten patients with classic RTT and ten untreated patients matched for age and clinical severity. Significant improvement in both the ISS (p = 0.0106) and RSS (p = 0.0274) was found in patients treated with IGF1 in comparison to untreated patients. Analysis of the novel RSS also suggests that patients treated with IGF1 have a greater endurance to social and cognitive testing. The present clinical study adds significant preliminary evidence for the use of IGF-1 in the treatment of RTT and other disorders of the autism spectrum.

  10. Serum levels of IGF-1 are related to human skin characteristics including the conspicuousness of facial pores.

    PubMed

    Sugiyama-Nakagiri, Y; Naoe, A; Ohuchi, A; Kitahara, T

    2011-04-01

    Conspicuous facial pores are one type of serious aesthetic defects for many women. However, the mechanism(s) that underlie the conspicuousness of facial pores remains unclear. We previously characterized the epidermal architecture around facial pores that correlates with the appearance of those pores in various ethnic groups including Japanese. The goal of this study was to evaluate the possible relationships between facial pore size, the severity of impairment of epidermal architecture around facial pores and sebum output levels to investigate the possible role of IGF-1 in the pathogenesis of conspicuous facial pores. The subjects consisted of 38 healthy Japanese women (aged 22-41 years). IGF-1 was measured using immunoradiometric assay. Surface replicas were collected to compare pore sizes of cheek skin and horizontal cross-section images of cheek skin were obtained non-invasively from the same subjects using in vivo confocal laser scanning microscopy and the severity of impairment of epidermal architecture around facial pores was determined. The skin surface lipids of each subject were collected from their cheeks and lipid classes were determined using gas chromatography/flame ionization detection. The serum level of IGF-1 correlated significantly with total pore area (R = 0.36, P < 0.05), with the severity of impairment of epidermal architecture around facial pores (R = 0.43, P < 0.05) and with sebum output levels (R = 0.41, P < 0.01). The sebum output levels correlated with total pore area (R = 0.32, P < 0.05). Our study found that serum levels of IGF-1 are correlated with facial skin characteristics including facial pore size and with the severity of impairment of epidermal architecture around facial pores.

  11. The synergistic effect of humanized monoclonal antibodies targeting insulin-like growth factor 1 receptor (IGF-1R) and chemotherapy.

    PubMed

    Sui, Ping; Cao, Hongxin; Meng, Long; Hu, Pingping; Ma, Honghai; Du, Jiajun

    2014-01-01

    IGF-1R, an important member of the IGF signaling system, is a plasma-membrane-bound receptor composed of two α-subunits and two β-subunits. IGF-1R has been revealed to play a pivotal role in cancer cell proliferation, differentiation, apoptosis and phenotype transformation, resulting uncontrolled tumor-cell growth. During the last decades, IGF-1R monoclonal antibody combined with chemotherapeutic agents as a novel cancer treatment approach has shown synergistic effect in cancer treatment in some preclinical and clinical trials. Prolonged progression-free survival rate, objective response rate and stable disease were shown in some sorts of cancer patients compared to those implemented traditional standard chemotherapy. However, not all related clinical trials demonstrated expected promising outcomes. Most treatment-related adverse events in those studies are mild and manageable. The most frequently happened side effect is hyperglycemia in majorities of combined cancer therapy studies. Herein, we summarized the recent online and published literatures concerning the safety, tolerability, anti-tumor activity and adverse events of this novel strategy. Besides, this work attempts to provide convincible evidence to warrant further investigation to identify prognostic biomarkers on neoplasm.

  12. Effects of space flight and IGF-1 on immune function

    NASA Astrophysics Data System (ADS)

    1999-01-01

    We tested the hypothesis that insulin-like growth factor-1 (IGF-1) would ameliorate space flight-induced effects on the immune system. Twelve male, Sprague-Dawley rats, surgically implanted with mini osmotic pumps, were subjected to space flight for 10 days on STS-77. Six rats received 10 mg/kg/day of IGF-1 and 6 rats received saline. Flight animals had a lymphocytopenia and granulocytosis which were reversed by IGF-1. Flight animals had significantly higher corticosterone levels than ground controls but IGF-1 did not impact this stress hormone. Therefore, the reversed granulocytosis did not correlate with serum corticosterone. Space flight and IGF-1 also combined to induce a monocytopenia that was not evident in ground control animals treated with IGF-1 or in animals subjected to space flight but given physiological saline. There was a significant increase in spleen weights in vivarium animals treated with IGF-1, however, this change did not occur in flight animals. We observed reduced agonist-induced lymph node cell proliferation by cells from flight animals compared to ground controls. The reduced proliferation was not augmented by IGF-1 treatment. There was enhanced secretion of TNF, IL-6 and NO by flight-animal peritoneal macrophages compared to vivarium controls, however, O2- secretion was not affected. These data suggest that IGF-1 can ameliorate some of the effects of space flight but that space flight can also impact the normal response to IGF-1.

  13. HER-3 peptide vaccines/mimics: Combined therapy with IGF-1R, HER-2, and HER-1 peptides induces synergistic antitumor effects against breast and pancreatic cancer cells

    PubMed Central

    Miller, Megan Jo; Foy, Kevin C; Overholser, Jay P; Nahta, Rita; Kaumaya, Pravin TP

    2014-01-01

    The human epidermal growth factor receptor 3 (HER-3/ErbB3) is a unique member of the human epidermal growth factor family of receptors, because it lacks intrinsic kinase activity and ability to heterodimerize with other members. HER-3 is frequently upregulated in cancers with epidermal growth factor receptor (EGFR/HER-1/ErbB1) or human epidermal growth factor receptor 2 (HER-2/ErBB2) overexpression, and targeting HER-3 may provide a route for overcoming resistance to agents that target EGFR or HER-2. We have previously developed vaccines and peptide mimics for HER-1, HER-2 and vascular endothelial growth factor (VEGF). In this study, we extend our studies by identifying and evaluating novel HER-3 peptide epitopes encompassing residues 99–122, 140–162, 237–269 and 461–479 of the HER-3 extracellular domain as putative B-cell epitopes for active immunotherapy against HER-3 positive cancers. We show that the HER-3 vaccine antibodies and HER-3 peptide mimics induced antitumor responses: inhibition of cancer cell proliferation, inhibition of receptor phosphorylation, induction of apoptosis and antibody dependent cellular cytotoxicity (ADCC). Two of the HER-3 epitopes 237–269 (domain II) and 461–479 (domain III) significantly inhibited growth of xenografts originating from both pancreatic (BxPC3) and breast (JIMT-1) cancers. Combined therapy of HER-3 (461–471) epitope with HER-2 (266–296), HER-2 (597–626), HER-1 (418–435) and insulin-like growth factor receptor type I (IGF-1R) (56–81) vaccine antibodies and peptide mimics show enhanced antitumor effects in breast and pancreatic cancer cells. This study establishes the hypothesis that combination immunotherapy targeting different signal transduction pathways can provide effective antitumor immunity and long-term control of HER-1 and HER-2 overexpressing cancers. PMID:25941588

  14. Renoprotective Effect of Lactoferrin against Chromium-Induced Acute Kidney Injury in Rats: Involvement of IL-18 and IGF-1 Inhibition

    PubMed Central

    Hegazy, Rehab; Salama, Abeer; Mansour, Dina; Hassan, Azza

    2016-01-01

    Hexavalent chromium (CrVI) is a heavy metal widely used in more than 50 industries. Nephrotoxicity is a major adverse effect of chromium poisoning. The present study investigated the potential renoprotective effect of lactoferrin (Lf) against potassium dichromate (PDC)-induced acute kidney injury (AKI) in rats. Beside, because previous studies suggest that interlukin-18 (IL-18) and insulin-like growth factor-1 (IGF-1) play important roles in promoting kidney damage, the present work aimed to evaluate the involvement of these two cytokines in PDC model of AKI and in the potential renoprotective effect of lactoferrin. Adult male albino Wistar rats were pretreated with Lf (200mg/kg/day, p.o.) or (300mg/kg/day, p.o.); the doses that are usually used in the experiment studies, for 14 days followed by a single dose of PDC (15mg/kg, s.c.). PDC caused significant increase in serum urea, creatinine, and total protein levels. This was accompanied with decreased renal glutathione content, and increased renal malondialdehyde, IL-18, IL-4, nuclear factor kappa B (NFκB), IGF-1, and the phosphorylated form of forkhead box protein O1 (FoxO1) levels. Moreover, normal expression IFN-γ mRNA and enhanced expression of TNF-α mRNA was demonstrated in renal tissues. Histopathological investigations provoked deleterious changes in the renal tissues. Tubular epithelial hyperplasia and apoptosis were demonstrated immunohistochemically by positive proliferating cell nuclear antigen (PCNA), Bax, and Caspase-3 expression, respectively. Pretreatment of rats with Lf in both doses significantly corrected all previously mentioned PDC-induced changes with no significant difference between both doses. In conclusion, the findings of the present study demonstrated the involvement of oxidative stress, inflammatory reactions, tubular hyperplasia and apoptosis in PDC-induced AKI. It suggested a role of IL-18 through stimulation of IL-4-induced inflammatory pathway, and IGF-1 through triggering FoxO1

  15. Boron supplementation inhibits the growth and local expression of IGF-1 in human prostate adenocarcinoma (LNCaP) tumors in nude mice.

    PubMed

    Gallardo-Williams, Maria T; Chapin, Robert E; King, Paula E; Moser, Glenda J; Goldsworthy, Thomas L; Morrison, James P; Maronpot, Robert R

    2004-01-01

    Prostate-specific antigen (PSA) is a serine protease and one of the most abundant proteins secreted by the human prostate epithelium. PSA is used as a well-established marker of prostate cancer. The involvement of PSA in several early events leading to the development of malignant prostate tumors has made it a target for prevention and intervention. It is thought that PSA cleaves insulin-like growth factor binding protein-3 (IGFBP-3), providing increased local levels of IGF-1, leading to tumor growth. Separately, there are data that suggest an enzymatic regulatory role for dietary boron, which is a serine protease inhibitor. In this study we have addressed the use of boric acid as a PSA inhibitor in an animal study. We have previously reported that low concentrations (6 ug/mL) of boric acid can partially inhibit the proteolytic activity of purified PSA towards a synthetic fluorogenic substrate. Also, by Western blot we have followed the degradation of fibronectin by enzymatically active PSA and have found significant inhibition in the presence of boric acid. We proposed that dietary supplementation with boric acid would inhibit PSA and reduce the development and proliferation of prostate carcinomas in an animal model. We tested this hypothesis using nude mice implanted subcutaneously with LNCaP cells in Matrigel. Two groups (10 animals/group) were dosed with boric acid solutions (1.7, 9.0 mgB/kg/day) by gavage. Control group received only water. Tumor sizes were measured weekly for 8 weeks. Serum PSA and IGF-1 levels were determined at terminal sacrifice. The size of tumors was decreased in mice exposed to the low and high dose of boric acid by 38% and 25%, respectively. Serum PSA levels decreased by 88.6% and 86.4%, respectively, as compared to the control group. There were morphological differences between the tumors in control and boron-dosed animals, including a significantly lower incidence of mitotic figures in the boron-supplemented groups. Circulating IGF-1

  16. Co-inhibition of EGFR and IGF1R synergistically impacts therapeutically on adrenocortical carcinoma

    PubMed Central

    Lian, Jianpo; Wang, Xiaojing; Ning, Guang; Wang, Weiqing; Zhu, Yu

    2016-01-01

    Purpose Adrenocortical carcinoma (ACC) is a rare tumor with very poor prognosis and no effective treatment. The aim of this study was to explore a novel therapy co-targeting EGFR and IGF1R in vitro and vivo. Methods The expression of EGFR and IGF1R were evaluated in a series of adrenocortical tumors by immunohistochemistry. Cell viability of ACC cell lines H295R and SW13 were determined by MTT assay after treatment with the combination of EGFR inhibitor Erlotinib and IGF1R inhibitor NVP-AEW541. Apoptosis was assessed by flow cytometry. The mechanism within intracellular signaling pathways was analyzed by Western blot. Mice bearing human ACC xenografts were treated with Erlotinib and NVP-AEW541, and the effects on tumour growth were assessed. Results Our results show a significant over-expression of EGFR (66.67%) and IGF1R (80.0%) in ACC. Besides, the co-overexpression of EGFR and IGF1R was seen in 8/15 ACCs, as compared with ACAs (P<0.05). Erlotinib and NVP-AEW541 significantly inhibited cell viability and induced apoptosis by blocking phosphorylation of MEK/ERK and AKT, respectively. Meanwhile, we found that single inhibition of IGF1R induced compensatory activation of MEK/ERK, leading to sustained activation of mTOR, which represent as aggregation of EGFR and IGF1R downstream components. More importantly, the combination of Erlotinib and NVP-AEW541 enhances anti-tumour efficacy compared to treatment with either agent alone or to untreated control in vitro and vivo. Conclusions In conclusion, coinhibition therapy targeting EGFR and IGF1R may be considerable for treatment of ACC in the future. PMID:27105537

  17. IGF-1 Receptor Inhibitors in Clinical Trials—Early Lessons

    PubMed Central

    Weroha, S. John

    2009-01-01

    The insulin-like growth factor pathway plays a major role in cancer cell proliferation, survival and resistance to anti-cancer therapies in many human malignancies, including breast cancer. As a key signaling component of IGF system, the IGF-1 receptor is the target of several investigational agents in clinical and pre-clinical development. This review will focus on the rationale for targeting the IGF-1 receptor and other components of the IGF-1 system. In addition, we will examine the role of IGF-1 signaling in resistance to clinically important breast cancer therapies, including cytotoxic chemotherapy, hormonal therapy and erbB targeted agents. We will also review the completed and ongoing clinical investigations with IGF-1 receptors inhibitors to date and the utility of these early data in designing future breast cancer studies with IGF-1 signaling inhibition strategies. PMID:19023648

  18. Curcumol Inhibits Growth and Induces Apoptosis of Colorectal Cancer LoVo Cell Line via IGF-1R and p38 MAPK Pathway

    PubMed Central

    Wang, Juan; Huang, Fengxiang; Bai, Zhun; Chi, Bixia; Wu, Jiacai; Chen, Xu

    2015-01-01

    Curcumol, isolated from the traditional medical plant Rhizoma Curcumae, is the bioactive component of Zedoary oil, whose potential anti-tumor effect has attracted considerable attention in recent years. Though many researchers have reported curcumol and its bioactivity, the potential molecular mechanism for its anti-cancer effect in colorectal cancer LoVo cells still remains unclear. In the present study, we found that curcumol showed growth inhibition and induced apoptosis of LoVo cells in a dose- and time-dependent manner. The occurrence of its proliferation inhibition and apoptosis came with suppression of IGF-1R expression, and then increased the phosphorylation of p38 mitogen activated protein kinase (MAPK), which might result in a cascade response by inhibiting the CREB survival pathway and finally triggered Bax/Bcl-2 and poly(ADP-ribose) polymerase 1 (PARP-1) apoptosis signals. Moreover, curcumol inhibited colorectal cancer in xenograft models of nude mice. Immunohistochemical and Western blot analysis revealed that curcumol could decrease the expression of ki-67, Bcl-2 as well as CREB1, and increase the expression of Bax and the phosphorylation of p38, which were consistent with our in vitro study. Overall, our in vitro and in vivo data confirmed the anti-cancer activity of curcumol, which was related to a significant inhibition of IGF-1R and activation of p38 MAPKs, indicating that curcumol may be a potential anti-tumor agent for colorectal carcinoma therapy. PMID:26307972

  19. Curcumol Inhibits Growth and Induces Apoptosis of Colorectal Cancer LoVo Cell Line via IGF-1R and p38 MAPK Pathway.

    PubMed

    Wang, Juan; Huang, Fengxiang; Bai, Zhun; Chi, Bixia; Wu, Jiacai; Chen, Xu

    2015-08-20

    Curcumol, isolated from the traditional medical plant Rhizoma Curcumae, is the bioactive component of Zedoary oil, whose potential anti-tumor effect has attracted considerable attention in recent years. Though many researchers have reported curcumol and its bioactivity, the potential molecular mechanism for its anti-cancer effect in colorectal cancer LoVo cells still remains unclear. In the present study, we found that curcumol showed growth inhibition and induced apoptosis of LoVo cells in a dose- and time-dependent manner. The occurrence of its proliferation inhibition and apoptosis came with suppression of IGF-1R expression, and then increased the phosphorylation of p38 mitogen activated protein kinase (MAPK), which might result in a cascade response by inhibiting the CREB survival pathway and finally triggered Bax/Bcl-2 and poly(ADP-ribose) polymerase 1 (PARP-1) apoptosis signals. Moreover, curcumol inhibited colorectal cancer in xenograft models of nude mice. Immunohistochemical and Western blot analysis revealed that curcumol could decrease the expression of ki-67, Bcl-2 as well as CREB1, and increase the expression of Bax and the phosphorylation of p38, which were consistent with our in vitro study. Overall, our in vitro and in vivo data confirmed the anti-cancer activity of curcumol, which was related to a significant inhibition of IGF-1R and activation of p38 MAPKs, indicating that curcumol may be a potential anti-tumor agent for colorectal carcinoma therapy.

  20. Sex, Sport, IGF-1 and the Community Effect in Height Hypothesis

    PubMed Central

    Bogin, Barry; Hermanussen, Michael; Blum, Werner F.; Aßmann, Christian

    2015-01-01

    We test the hypothesis that differences in social status between groups of people within a population may induce variation in insulin-like growth factor-1(IGF-1) levels and, by extension, growth in height. This is called the community effect in height hypothesis. The relationship between IGF-1, assessed via finger-prick dried blood spot, and elite level sport competition outcomes were analysed for a sample of 116 undergraduate men and women. There was a statistically significant difference between winners and losers of a competition. Winners, as a group, had higher average pre-game and post-game IGF-1 levels than losers. We proposed this type of difference as a proxy for social dominance. We found no evidence that winners increased in IGF-1 levels over losers or that members of the same team were more similar in IGF-1 levels than they were to players from other teams. These findings provide limited support toward the community effect in height hypothesis. The findings are discussed in relation to the action of the growth hormone/IGF-1 axis as a transducer of multiple bio-social influences into a coherent signal which allows the growing human to adjust and adapt to local ecological conditions. PMID:25946190

  1. Glucose Induces Sensitivity to Oxygen Deprivation and Modulates Insulin/IGF-1 Signaling and Lipid Biosynthesis in Caenorhabditis elegans

    PubMed Central

    Garcia, Anastacia M.; Ladage, Mary L.; Dumesnil, Dennis R.; Zaman, Khadiza; Shulaev, Vladimir; Azad, Rajeev K.; Padilla, Pamela A.

    2015-01-01

    Diet is a central environmental factor that contributes to the phenotype and physiology of individuals. At the root of many human health issues is the excess of calorie intake relative to calorie expenditure. For example, the increasing amount of dietary sugars in the human diet is contributing to the rise of obesity and type 2 diabetes. Individuals with obesity and type 2 diabetes have compromised oxygen delivery, and thus it is of interest to investigate the impact a high-sugar diet has on oxygen deprivation responses. By utilizing the Caenorhabditis elegans genetic model system, which is anoxia tolerant, we determined that a glucose-supplemented diet negatively impacts responses to anoxia and that the insulin-like signaling pathway, through fatty acid and ceramide synthesis, modulates anoxia survival. Additionally, a glucose-supplemented diet alters lipid localization and initiates a positive chemotaxis response. Use of RNA-sequencing analysis to compare gene expression responses in animals fed either a standard or glucose-supplemented diet revealed that glucose impacts the expression of genes involved with multiple cellular processes including lipid and carbohydrate metabolism, stress responses, cell division, and extracellular functions. Several of the genes we identified show homology to human genes that are differentially regulated in response to obesity or type 2 diabetes, suggesting that there may be conserved gene expression responses between C. elegans fed a glucose-supplemented diet and a diabetic and/or obesity state observed in humans. These findings support the utility of the C. elegans model for understanding the molecular mechanisms regulating dietary-induced metabolic diseases. PMID:25762526

  2. A two year observation of the process of applying recombinant IGF-1 to treat short stature in children with primary IGF-1 deficiency -- case reports of 3 patients.

    PubMed

    Petriczko, Elżbieta; Wikiera, Beata; Horodnicka-Józwa, Anita; Marcinkiewicz, Katarzyna; Szmit-Domagalska, Justyna; Kędzia, Andrzej; Durzyńska, Julia; Broniarczyk, Justyna; Gabryelczyk, Bartosz; Noczyńska, Anna; Walczak, Mieczysław

    2011-01-01

    Growth deficiency is one of the most frequent causes of referral to Endocrinology Outpatient Clinic. IGF-1 (insulin-like growth factor 1) deficiency is one of the rarest causes of short stature. In 2009 in Poland a therapeutic programme was set up for children with severe primary IGF-1 deficiency. The authors present the data of three first polish patients qualified for the rhIGF-1 (recombinant human insulin-like growth factor 1) - mecasermin. The authors conclude that the treatment with rhIGF-1 significantly improves growth velocity in patients with IGF-1 deficiency. During two years of mecasermin treatment no serious side effects were noted.

  3. Role of PI3K/Akt signaling in insulin-like growth factor-1 (IGF-1) skin tumor promotion.

    PubMed

    Wilker, Erik; Lu, Jerry; Rho, Okkyung; Carbajal, Steve; Beltrán, Linda; DiGiovanni, John

    2005-10-01

    Overexpression of human IGF-1 with the bovine keratin 5 (BK5) promoter (BK5.IGF-1 transgenic mice) induces persistent epidermal hyperplasia and leads to spontaneous skin tumor formation. In previous work, PI3K and Akt activities were found to be elevated in the epidermis of BK5.IGF-1 transgenic mice compared to nontransgenic littermates. In the present study, we examined the importance of the PI3K/Akt signaling pathway in mediating the skin phenotype and the skin tumor promoting action of IGF-1 in these mice. Western blot analyses with epidermal lysates showed that signaling components downstream of PI3K/Akt were altered in epidermis of BK5.IGF-1 mice. Increased phosphorylation of GSK-3 (Ser(9/21)), TSC2(Thr(1462)), and mTOR(Ser(2448)) was observed. In addition, hypophosphorylation and increased protein levels of beta-catenin were observed in the epidermis of BK5.IGF-1 mice. These data suggested that components downstream of Akt might be affected, including cell cycle machinery in the epidermis of BK5.IGF-1 mice. Protein levels of cyclins (D1, E, A), E2F1, and E2F4 were all elevated in the epidermis of BK5.IGF-1 mice. Also, immunoprecipitation experiments demonstrated an increase in cdk4/cyclin D1 and cdk2/cyclin E complex formation, suggesting increased cdk activity in the epidermis of transgenic mice. In further studies, the PI3K inhibitor, LY294002, significantly blocked IGF-1-mediated epidermal proliferation and skin tumor promotion in DMBA-initiated BK5.IGF-1 mice. In addition, inhibition of PI3K/Akt with LY294002 reversed many of the cell cycle related changes observed in untreated transgenic animals. Collectively, the current results supported the hypothesis that elevated PI3K/Akt activity and subsequent activation of one or more downstream effector pathways contributed significantly to the tumor promoting action of IGF-1 in the epidermis of BK5.IGF-1 mice.

  4. Growth hormone insensitivity syndrome (Laron syndrome): main characteristics and effects of IGF1 treatment.

    PubMed

    Carel, J C; Chaussain, J L; Chatelain, P; Savage, M O

    1996-07-01

    Growth hormone (GH) insensitivity is a pathological state characterized by a disturbance of the physiological relationship between GH secretion, synthesis of insulin-like growth-factor I (IGF-1) and the biological actions of GH. Laron syndrome, the prototype for GH insensitivity, is most often due to GH receptor deficiency. However, this syndrome is heterogeneous in terms of growth characteristics, bio-chemical features and, most importantly, genetic defects. Recent data have indicated that partial GH receptor deficiency could be involved in children with apparently idiopathic short stature. Laron syndrome, because of extreme growth deficiency and a lack of alternative treatment, was the first clinical situation in which recombinant human IGF-1 was used. IGF-1 accelerates growth rate in most patients, induces subtle modifications of the craniofacies and decreases fat mass. However, it is still too early to evaluate the long-term effects of IGF-1 on final height. Tolerance to the drug has been excellent in all reported trials. The major (but rare) side effects are transient intracranial hypertension and hypokalemia. Generalization of data obtained in Laron syndrome to other clinical situations should take account of the profound alterations in IGF-1 pharmacokinetics resulting from a deficiency in IGF-binding proteins.

  5. Role of insulin-like growth factor-1 (IGF-1) in regulating cell cycle progression

    SciTech Connect

    Ma, Qi-lin; Yang, Tian-lun; Yin, Ji-ye; Peng, Zhen-yu; Yu, Min; Liu, Zhao-qian; Chen, Fang-ping

    2009-11-06

    Aims: Insulin-like growth factor-1 (IGF-1) is a polypeptide protein hormone, similar in molecular structure to insulin, which plays an important role in cell migration, cell cycle progression, cell survival and proliferation. In this study, we investigated the possible mechanisms of IGF-1 mediated cell cycle redistribution and apoptosis of vascular endothelial cells. Method: Human umbilical vein endothelial cells (HUVECs) were pretreated with 0.1, 0.5, or 2.5 {mu}g/mL of IGF-1 for 30 min before the addition of Ang II. Cell cycle redistribution and apoptosis were examined by flow cytometry. Expression of Ang II type 1 (AT{sub 1}) mRNA and cyclin E protein were determined by RT-PCR and Western blot, respectively. Results: Ang II (1 {mu}mol/L) induced HUVECs arrested at G{sub 0}/G{sub 1}, enhanced the expression level of AT{sub 1} mRNA in a time-dependent manner, reduced the enzymatic activity of nitric oxide synthase (NOS) and nitric oxide (NO) content as well as the expression level of cyclin E protein. However, IGF-1 enhanced NOS activity, NO content, and the expression level of cyclin E protein, and reduced the expression level of AT{sub 1} mRNA. L-NAME significantly counteracted these effects of IGF-1. Conclusions: Our data suggests that IGF-1 can reverse vascular endothelial cells arrested at G{sub 0}/G{sub 1} and apoptosis induced by Ang II, which might be mediated via a NOS-NO signaling pathway and is likely associated with the expression levels of AT1 mRNA and cyclin E proteins.

  6. The Role of Integrins and IGFBPs in the IGF-1 Stimulated Migration of Human Breast Cancer Cells

    DTIC Science & Technology

    1997-06-01

    animals, the investigator(s) adhered to the "Guide for the Care and Use of Laboratory Animals," prepared by the Committee on Care and use of...Arteaga, C.L., L.J. Kitten , E.B. Coronado, et al. 1989. Blockage of the Type I Somatomedin Receptor Inhibits Growth of Human Breast Cancer Cells in

  7. XGFR*, a novel affinity-matured bispecific antibody targeting IGF-1R and EGFR with combined signaling inhibition and enhanced immune activation for the treatment of pancreatic cancer

    PubMed Central

    Schanzer, Juergen M.; Wartha, Katharina; Moessner, Ekkehard; Hosse, Ralf J.; Moser, Samuel; Croasdale, Rebecca; Trochanowska, Halina; Shao, Cuiying; Wang, Peng; Shi, Lei; Weinzierl, Tina; Rieder, Natascha; Bacac, Marina; Ries, Carola H.; Kettenberger, Hubert; Schlothauer, Tilman; Friess, Thomas; Umana, Pablo; Klein, Christian

    2016-01-01

    ABSTRACT The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the “knobs-into-holes” technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2–3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer. PMID:26984378

  8. Prenatal cocaine alone and combined with nicotine alters ANG II and IGF-1 induced left atrial contractions in aging male offspring.

    PubMed

    Haddad, Georges E; Scheer, Alexandre; Clarke, Elijah; Arguinzoni, Jason K; Sobrian, Sonya K

    2005-11-01

    Prenatal cocaine or nicotine affects inotropic activity in the hearts of rat offspring. However, the long-term consequence of this exposure on the cardiac response to hormonal challenge is unknown. We assessed the inotropic effects of angiotensin II (ANG II) and insulin-like growth factor 1 (IGF-1) in the left atria of 19.0-24.5 month-old male rats exposed on gestation days 8-21 to 1 of 6 treatments: low cocaine (LC) (20 mg/kg) or high cocaine (HC) (40 mg/kg); 20 mg/kg cocaine and high nicotine (5 mg/kg nicotine) (LC/HN); 40 mg/kg cocaine and low nicotine (2.5 mg/kg nicotine) (HC/LN); pair fed: yoked to HC (PF); saline: injection of 0.9% NaCl (SAL). Isometric contractions were assessed by electrical stimulation of isolated left atria superfused with Tyrode solution (control) to which ANG II (10-7 mol/L, 20 min) and IGF-1 (10-8 mol/L, 20 min) in the presence of ANG II were added sequentially. Offspring in all cocaine groups showed a higher peak tension development (PTD) to ANG II than PF controls. This increase in PTD was attenuated by subsequent addition of IGF-1 in all except HC offspring. However, with the HC/LN combination the IGF-1 effect on PTD was again evident. The velocities of contraction and relaxation were positively affected by ANG II only in the combined prenatal drug groups; IGF-1 reduced only contraction velocity. Our data demonstrate that IGF-1 reverses the positive inotropic effect of ANG-II in atrial muscle of aging rats and that gestational exposure to only high doses of cocaine eliminates this protective response. It appears that combined prenatal exposure to cocaine and nicotine does not exacerbate the decline in cardiac function and responsiveness to inotropic drugs seen in the aging heart.

  9. IGF-1R Inhibition Activates a YES/SFK Bypass Resistance Pathway: Rational Basis for Co-Targeting IGF-1R and Yes/SFK Kinase in Rhabdomyosarcoma.

    PubMed

    Wan, Xiaolin; Yeung, Choh; Heske, Christine; Mendoza, Arnulfo; Helman, Lee J

    2015-04-01

    The insulin-like growth factor 1 receptor (IGF-1R) has surfaced as a significant target in multiple solid cancers due to its fundamental roles in pro-survival and anti-apoptotic signaling. However, development of resistance to IGF-1R blockade represents a significant hindrance and limits treatment efficacy in the clinic. In this study, we identified acquired resistance to IGF-1R blockade with R1507, an antibody against IGF-1R, and with BMS-754807, a small molecular inhibitor of IGF-1R/insulin receptor (IR). We showed that treatment with an IGF-IR antibody, R1507, or an IR/IGF-IR kinase inhibitor, BMS-754807, was associated with increased activation of YES/SRC family tyrosine kinase (SFK) in rhabdomyosarcoma (RMS). Combining anti-IGF-1R agents with SFK inhibitors resulted in blockade of IGF-1R inhibition-induced activation of YES/SFK and displayed advantageous antitumor activity in vitro and in vivo. Our data provide evidence that IGF-1R blockade results in activation of the YES/SRC family kinase bypass resistance pathway in vitro and in vivo. This may be of particular clinical relevance since both Yes and IGF components are overexpressed in RMS. Increased YES/SFK activation might serve as a clinical biomarker for predicting tumor resistance to IGF-1R inhibition. Dual inhibition of IGF-1R and SFK may have a broader and enhanced clinical benefit for patients with RMS.

  10. Migration- and exercise-induced changes to flight muscle size in migratory birds and association with IGF1 and myostatin mRNA expression.

    PubMed

    Price, Edwin R; Bauchinger, Ulf; Zajac, Daria M; Cerasale, David J; McFarlan, Jay T; Gerson, Alexander R; McWilliams, Scott R; Guglielmo, Christopher G

    2011-09-01

    Seasonal adjustments to muscle size in migratory birds may result from preparatory physiological changes or responses to changed workloads. The mechanisms controlling these changes in size are poorly understood. We investigated some potential mediators of flight muscle size (myostatin and insulin-like growth factor, IGF1) in pectoralis muscles of wild wintering or migrating white-throated sparrows (Zonotrichia albicollis), captive white-throated sparrows that were photoperiod manipulated to be in a `wintering' or `migratory' (Zugunruhe) state, and captive European starlings (Sturnus vulgaris) that were either exercised for 2 weeks in a wind tunnel or untrained. Flight muscle size increased in photo-stimulated `migrants' and in exercised starlings. Acute exercise but not long-term training caused increased expression of IGF1, but neither caused a change in expression of myostatin or its metalloprotease activator TLL1. Photo-stimulated `migrant' sparrows demonstrated increased expression of both myostatin and IGF1, but wild sparrows exhibited no significant seasonal changes in expression of either myostatin or IGF1. Additionally, in both study species we describe several splice variants of myostatin that are shared with distantly related bird species. We demonstrate that their expression patterns are not different from those of the typical myostatin, suggesting that they have no functional importance and may be mistakes of the splicing machinery. We conclude that IGF1 is likely to be an important mediator of muscle phenotypic flexibility during acute exercise and during endogenous, seasonal preparation for migration. The role of myostatin is less clear, but its paradoxical increase in photo-stimulated `migrants' may indicate a role in seasonal adjustments of protein turnover.

  11. Intraplacental gene therapy with Ad-IGF-1 corrects naturally occurring rabbit model of intrauterine growth restriction.

    PubMed

    Keswani, Sundeep G; Balaji, Swathi; Katz, Anna B; King, Alice; Omar, Khaled; Habli, Mounira; Klanke, Charles; Crombleholme, Timothy M

    2015-03-01

    Intrauterine growth restriction (IUGR) due to placental insufficiency is a leading cause of perinatal complications for which there is no effective prenatal therapy. We have previously demonstrated that intraplacental injection of adenovirus-mediated insulin-like growth factor-1 (Ad-IGF-1) corrects fetal weight in a murine IUGR model induced by mesenteric uterine artery branch ligation. This study investigated the effect of intraplacental Ad-IGF-1 gene therapy in a rabbit model of naturally occurring IUGR (runt) due to placental insufficiency, which is similar to the human IUGR condition with onset in the early third trimester, brain sparing, and a reduction in liver weight. Laparotomy was performed on New Zealand White rabbits on day 21 of 30 days of gestation and litters were divided into five groups: Control (first position)+phosphate-buffered saline (PBS), control+Ad-IGF-1, runt (third position)+PBS, runt+Ad-IGF-1, and runt+Ad-LacZ. The effect of IGF-1 gene therapy on fetal, placental, liver, heart, lung, and musculoskeletal weights of the growth-restricted pups was examined. Protein expression after gene transfer was seen along the maternal-fetal placenta interface (n=12) 48 hr after gene therapy. There was minimal gene transfer detected in the pups or maternal organs. At term, compared with the normally grown first-position control, the runted third-position pups demonstrated significantly lower fetal, placental, liver, lung, and musculoskeletal weights. The fetal, liver, and musculoskeletal weights were restored to normal by intraplacental Ad-IGF-1 gene therapy (p<0.01), with no change in the placental weight. Intraplacental gene therapy is a novel strategy for the treatment of IUGR caused by placental insufficiency that takes advantage of an organ that will be discarded at birth. Development of nonviral IGF-1 gene delivery using placenta-specific promoters can potentially minimize toxicity to the mother and fetus and facilitate clinical translation of

  12. Co-expression of Dsb proteins enables soluble expression of a single-chain variable fragment (scFv) against human type 1 insulin-like growth factor receptor (IGF-1R) in E. coli.

    PubMed

    Sun, Xue-Wen; Wang, Xiao-Hua; Yao, Yan-Bing

    2014-12-01

    Type 1 insulin-like growth factor receptor (IGF-1R) is a promising therapeutic target for cancer treatment. A single-chain variable fragment (scFv) against human IGF-1R forms inclusion body when expressed in periplasmic space of E. coli routinely. Here, we described that co-expression of appropriate disulfide bonds (Dsb) proteins known to catalyze the formation and isomerization of Dsb can markedly recover the soluble expression of target scFv in E. coli. A 50 % recovery in solubility of the scFv was observed upon co-expression of DsbC alone, and a maximum solubility (80 %) was obtained when DsbA and DsbC were co-expressed in combination. Furthermore, the soluble scFv present full antigen-binding activity with IGF-1R, suggesting its correct folding. This study also suggested that the selection of Dsb proteins should be tested case-by-case if the approach of co-expression of Dsb system is adopted to address the problem of insoluble expression of proteins carrying Dsb.

  13. IGF1R signaling acts on the anagen to catagen transition in the hair cycle.

    PubMed

    Castela, Mathieu; Linay, Fabien; Roy, Edwige; Moguelet, Philippe; Xu, Jie; Holzenberger, Martin; Khosrotehrani, Kiarash; Aractingi, Selim

    2017-01-17

    Insulin like growth factor 1 (IGF1) is important for skin development and homeostasis. However, overexpression and inactivation studies have produced variable findings regarding its role in hair follicle (HF) biology. Here, we studied a conditional and inducible knockout of the IGF1 receptor (IGF1R) in keratin 15-expressing bulge cells. Deletion of IGF1R after the development of the skin appendages in K15-IGF1R(KO) mice showed no abnormalities in epidermal homeostasis. Numbers of bulge cells were lower in K15-IGF1R(KO) mice than in controls, without consequences on wound healing, at least in young mice. K15-IGF1R(KO) HFs entered anagen phase earlier than controls and showed a delay in the anagen/catagen switch. The expression of BMP-4 mRNA was inhibited in HFs from K15-IGF1R(KO) . MED1 transcription was impaired in the epidermis of K15-IGF1R(KO) mice. These findings suggest that IGF1R controls the hair cycle, partly through BMP-4 activation. This article is protected by copyright. All rights reserved.

  14. IGF-1 and Survival in ESRD

    PubMed Central

    Jia, Ting; Gama Axelsson, Thiane; Heimbürger, Olof; Bárány, Peter; Stenvinkel, Peter; Qureshi, Abdul Rashid

    2014-01-01

    Summary Background and objectives IGF-1 deficiency links to malnutrition in CKD patients; however, it is not clear to what extent it associates with survival among these patients. Design, setting, participants, & measurements Serum IGF-1 and other biochemical, clinical (subjective global assessment), and densitometric (dual energy x-ray absorptiometry) markers of nutritional status and mineral and bone metabolism were measured in a cohort of 365 Swedish clinically stable CKD stage 5 patients (median age of 53 years) initiating dialysis between 1994 and 2009; in 207 patients, measurements were also taken after 1 year of dialysis. Deaths were registered during a median follow-up of 5 years. Associations of mortality with baseline IGF-1 and changes of IGF-1 after 1 year of dialysis were evaluated by Cox models. Results At baseline, IGF-1 concentrations associated negatively with age, diabetes mellitus, cardiovascular disease, poor nutritional status, IL-6, and osteoprotegerin and positively with body fat mass, bone mineral density, serum phosphate, calcium, and fibroblast growth factor-23. At 1 year, IGF-1 had increased by 33%. In multivariate regression, low age, diabetes mellitus, and high serum phosphate and calcium associated with IGF-1 at baseline, and in a mixed model, these factors, together with high fat body mass, associated with changes of IGF-1 during the first 1 year of dialysis. Adjusting for calendar year of inclusion, age, sex, diabetes mellitus, cardiovascular disease, IL-6, and poor nutritional status, a 1 SD higher level of IGF-1 at baseline associated with lower mortality risk (hazard ratio, 0.57; 95% confidence interval, 0.32 to 0.98). Persistently low or decreasing IGF-1 levels during the first 1 year on dialysis predicted worse survival (adjusted hazard ratio, 2.19; 95% confidence interval, 1.06 to 4.50). Conclusion In incident dialysis patients, low serum IGF-1 associates with body composition and markers of mineral and bone metabolism, and it

  15. Estrogen Receptor-β Up-Regulates IGF1R Expression and Activity to Inhibit Apoptosis and Increase Growth of Medulloblastoma

    PubMed Central

    Cookman, Clifford J.

    2015-01-01

    Medulloblastoma (Med) is the most common malignant brain tumor in children. The role of ESR2 [estrogen receptor (ER)-β] in promoting Med growth was comprehensively examined in three in vivo models and human cell lines. In a novel Med ERβ-null knockout model developed by crossing Esr2−/− mice with cerebellar granule cell precursor specific Ptch1 conditional knockout mice, the tumor growth rate was significantly decreased in males and females. The absence of Esr2 resulted in increased apoptosis, decreased B-cell lymphoma 2 (BCL2), and IGF-1 receptor (IGF1R) expression, and decreased levels of active MAPKs (ERK1/2) and protein kinase B (AKT). Treatment of Med in Ptch1+/− Trp53−/− mice with the antiestrogen chemotherapeutic drug Faslodex significantly increased symptom-free survival, which was associated with increased apoptosis and decreased BCL2 and IGF1R expression and signaling. Similar effects were also observed in nude mice bearing D283Med xenografts. In vitro studies in human D283Med cells metabolically stressed by glutamine withdrawal found that 17β-estradiol and the ERβ selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile dose dependently protected Med cells from caspase-3-dependent cell death. Those effects were associated with increased phosphorylation of IGF1R, long-term increases in ERK1/2 and AKT signaling, and increased expression of IGF-1, IGF1R, and BCL2. Results of pharmacological experiments revealed that the cytoprotective actions of estradiol were dependent on ERβ and IGF1R receptor tyrosine kinase activity and independent of ERα and G protein-coupled estrogen receptor 1 (G protein coupled receptor 30). The presented results demonstrate that estrogen promotes Med growth through ERβ-mediated increases in IGF1R expression and activity, which induce cytoprotective mechanisms that decrease apoptosis. PMID:25885794

  16. IGF-1/IGF-1R/hsa-let-7c axis regulates the committed differentiation of stem cells from apical papilla

    PubMed Central

    Ma, Shu; Liu, Genxia; Jin, Lin; Pang, Xiyao; Wang, Yanqiu; Wang, Zilu; Yu, Yan; Yu, Jinhua

    2016-01-01

    Insulin-like growth factor-1 (IGF-1) and its receptor IGF-1R play a paramount role in tooth/bone formation while hsa-let-7c actively participates in the osteogenic differentiation of mesenchymal stem cells. However, the interaction between IGF-1/IGF-1R and hsa-let-7c on the committed differentiation of stem cells from apical papilla (SCAPs) remains unclear. In this study, human SCAPs were isolated and treated with IGF-1 and hsa-let-7c over/low-expression viruses. The odonto/osteogenic differentiation of these stem cells and the involvement of mitogen-activated protein kinase (MAPK) pathway were subsequently investigated. Alizarin red staining showed that hsa-let-7c low-expression can significantly promote the mineralization of IGF-1 treated SCAPs, while hsa-let-7c over-expression can decrease the calcium deposition of IGF-1 treated SCAPs. Western blot assay and real-time reverse transcription polymerase chain reaction further demonstrated that the expression of odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, COL-I/COL-I, DSPP/DSP, and DMP-1/DMP-1) in IGF-1 treated SCAPs were significantly upregulated in Let-7c-low group. On the contrary, hsa-let-7c over-expression could downregulate the expression of these odonto/osteogenic markers. Moreover, western blot assay showed that the JNK and p38 MAPK signaling pathways were activated in Let-7c-low SCAPs but inhibited in Let-7c-over SCAPs. Together, the IGF-1/IGF-1R/hsa-let-7c axis can control the odonto/osteogenic differentiation of IGF-1-treated SCAPs via the regulation of JNK and p38 MAPK signaling pathways. PMID:27833148

  17. The regulation of IGF-1 by leptin in the pig is tissue specific and independent of changes in growth hormone.

    PubMed

    Ajuwon, Kolapo M; Kuske, Joanne L; Ragland, Darryl; Adeola, Olayiwola; Hancock, Deana L; Anderson, David B; Spurlock, Michael E

    2003-09-01

    A combination of in vivo and in vitro experiments were performed to determine the extent to which exogenous leptin regulates serum growth hormone (GH) and insulin-like growth factor I (IGF-1) concentrations, and the abundance of IGF-1 mRNA in major peripheral tissues. Initially (Experiment 1), a recombinant human leptin analog was administered i.m. to young growing pigs (approximately 27 kg body weight) for 15 days at 0 (control), 0.003, 0.01 and 0.03 mg. kg(-1). day(-1). Although there was no sustained effect of leptin on serum GH, there was a reduction (P < 0.02) in serum IGF-1 at the intermediate dose that paralleled a decrease (P < 0.09) in hepatic IGF-1 expression. Leptin, at these doses, did not reduce feed intake (P > 0.57), nor was there an effect of leptin on dietary nitrogen retention (P > 0.97). In a second experiment, pigs were injected with vehicle or a higher dose of leptin (0.05 mg. kg(-1). day(-1)) for 14 days. A third treatment group was injected with vehicle and pair-fed to the intake of the group treated with leptin. In this study, exogenous leptin resulted in a sustained increase in serum leptin (P < 0.0001) and reduction in feed intake of approximately 30% (P < 0.0001). Serum IGF-1 was depressed in both the leptin-treated and pair-fed groups, relative to the group allowed ad-libitum intake (P < 0.01). Furthermore, there was no difference among treatments in the relative abundance of IGF-1 mRNA in skeletal muscle (P > 0.42) or adipose tissue (P > 0.26), and liver mRNA abundance was actually increased (P < 0.01) by leptin, despite the lower feed intake. Finally, to determine whether leptin altered the secretion of IGF-1 by isolated pig hepatocytes, primary cultures were incubated with leptin for 24 to 48 hr (Experiment 3). Leptin (100 nM) caused a sharp reduction (P < 0.0001) in dexamethasone-induced IGF-1 secretion at 24 hr (47% reduction) and at 48 hr (40% reduction). Collectively, these data indicate that leptin may regulate hepatic IGF-1

  18. IGF-1 and Bone: New Discoveries From Mouse Models

    PubMed Central

    Yakar, Shoshana; Courtland, Hayden-William; Clemmons, David

    2010-01-01

    Insulin-like growth factor-1 (IGF-1) plays a central role in cellular growth, differentiation, survival, and cell cycle progression. It is expressed early during development and its effects are mediated through binding to a tyrosine kinase receptor, the insulin-like growth factor-1 receptor (IGF-1R). In the circulation, the IGFs bind to IGF-binding proteins (IGFBPs), which determine their bioavailability and regulate the interaction between the IGFs and IGF-1R. Studies in animal models and in humans have established critical roles for IGFs in skeletal growth and development. In this review we present new and old findings from mouse models of the IGF system and discuss their clinical relevance to normal and pathological skeletal physiology. © 2010 American Society for Bone and Mineral Research. PMID:20836088

  19. Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis

    PubMed Central

    Locatelli, Vittorio; Bianchi, Vittorio E.

    2014-01-01

    Background. Growth hormone (GH) and insulin-like growth factor (IGF-1) are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone metabolism in osteopenic and osteoporotic human subjects and on bone healing in operated patients with normal GH secretion. Eighteen clinical studies considered the effect with GH treatment, fourteen studies reported the clinical effects with IGF-1 administration, and seven related to the GH/IGF-1 effect on bone healing. Results. Both GH and IGF-1 administration significantly increased bone resorption and bone formation in the most studies. GH/IGF-1 administration in patients with hip or tibial fractures resulted in increased bone healing, rapid clinical improvements. Some conflicting results were evidenced. Conclusions. GH and IGF-1 therapy has a significant anabolic effect. GH administration for the treatment of osteoporosis and bone fractures may greatly improve clinical outcome. GH interacts with sex steroids in the anabolic process. GH resistance process is considered. PMID:25147565

  20. Central insulin-like growth factor-1 (IGF-1) restores whole-body insulin action in a model of age-related insulin resistance and IGF-1 decline.

    PubMed

    Huffman, Derek M; Farias Quipildor, Gabriela; Mao, Kai; Zhang, Xueying; Wan, Junxiang; Apontes, Pasha; Cohen, Pinchas; Barzilai, Nir

    2016-02-01

    Low insulin-like growth factor-1 (IGF-1) signaling is associated with improved longevity, but is paradoxically linked with several age-related diseases in humans. Insulin-like growth factor-1 has proven to be particularly beneficial to the brain, where it confers protection against features of neuronal and cognitive decline. While aging is characterized by central insulin resistance in the face of hyperinsulinemia, the somatotropic axis markedly declines in older humans. Thus, we hypothesized that increasing IGF-1 in the brain may prove to be a novel therapeutic alternative to overcome central insulin resistance and restore whole-body insulin action in aging. Utilizing hyperinsulinemic-euglycemic clamps, we show that old insulin-resistant rats with age-related declines in IGF-1 level demonstrate markedly improved whole-body insulin action, when treated with central IGF-1, as compared to central vehicle or insulin (P < 0.05). Furthermore, central IGF-1, but not insulin, suppressed hepatic glucose production and increased glucose disposal rates in aging rats (P < 0.05). Taken together, IGF-1 action in the brain and periphery provides a 'balance' between its beneficial and detrimental actions. Therefore, we propose that strategies aimed at 'tipping the balance' of IGF-1 action centrally are the optimal approach to achieve healthy aging and longevity in humans.

  1. IGF-1 administration to prepubertal female rats can overcome delayed puberty caused by maternal Pb exposure.

    PubMed

    Pine, Michelle D; Hiney, Jill K; Dearth, Robert K; Bratton, Gerald R; Dees, W Les

    2006-01-01

    Because prepubertal female rats maternally exposed to lead (Pb) exhibit suppressed serum levels of insulin-like growth factor-1 (IGF-1) and delayed puberty, we investigated the ability of centrally administered IGF-1 to stimulate luteinizing hormone (LH) release in vivo and LH-releasing hormone (LHRH) release in vitro from maternally Pb-exposed prepubertal female rats. Additionally, we assessed whether IGF-1 replacement could affect the timing of female puberty. Results demonstrated that IGF-1 stimulated significantly LH release in both control and Pb-exposed animals. When median eminences from control and Pb-exposed females were incubated with rat IGF-1 in vitro, they responded similarly with significant peptide-induced LHRH release. Lastly, we showed IGF-1 replacement reversed the delay in puberty caused by Pb. These results indicate the central LHRH response to IGF-1 is intact and that Pb-induced delayed puberty is due, at least in part, to suppressed circulating IGF-1 available to the hypothalamus.

  2. Paracrine Effects of IGF-1 Overexpression on the Functional Decline Due to Skeletal Muscle Disuse: Molecular and Functional Evaluation in Hindlimb Unloaded MLC/mIgf-1 Transgenic Mice

    PubMed Central

    Cannone, Maria; Liantonio, Antonella; De Bellis, Michela; Digennaro, Claudio; Gramegna, Gianluca; De Luca, Annamaria; Germinario, Elena; Danieli-Betto, Daniela; Betto, Romeo; Dobrowolny, Gabriella; Rizzuto, Emanuele; Musarò, Antonio; Desaphy, Jean-François; Camerino, Diana Conte

    2013-01-01

    Slow-twitch muscles, devoted to postural maintenance, experience atrophy and weakness during muscle disuse due to bed-rest, aging or spaceflight. These conditions impair motion activities and can have survival implications. Human and animal studies demonstrate the anabolic role of IGF-1 on skeletal muscle suggesting its interest as a muscle disuse countermeasure. Thus, we tested the role of IGF-1 overexpression on skeletal muscle alteration due to hindlimb unloading (HU) by using MLC/mIgf-1 transgenic mice expressing IGF-1 under the transcriptional control of MLC promoter, selectively activated in skeletal muscle. HU produced atrophy in soleus muscle, in terms of muscle weight and fiber cross-sectional area (CSA) reduction, and up-regulation of atrophy gene MuRF1. In parallel, the disuse-induced slow-to-fast fiber transition was confirmed by an increase of the fast-type of the Myosin Heavy Chain (MHC), a decrease of PGC-1α expression and an increase of histone deacetylase-5 (HDAC5). Consistently, functional parameters such as the resting chloride conductance (gCl) together with ClC-1 chloride channel expression were increased and the contractile parameters were modified in soleus muscle of HU mice. Surprisingly, IGF-1 overexpression in HU mice was unable to counteract the loss of muscle weight and the decrease of fiber CSA. However, the expression of MuRF1 was recovered, suggesting early effects on muscle atrophy. Although the expression of PGC-1α and MHC were not improved in IGF-1-HU mice, the expression of HDAC5 was recovered. Importantly, the HU-induced increase of gCl was fully contrasted in IGF-1 transgenic mice, as well as the changes in contractile parameters. These results indicate that, even if local expression does not seem to attenuate HU-induced atrophy and slow-to-fast phenotype transition, it exerts early molecular effects on gene expression which can counteract the HU-induced modification of electrical and contractile properties. MuRF1 and HDAC5

  3. Inhibition of IGF-1 signaling by genistein: modulation of E-cadherin expression and downregulation of β-catenin signaling in hormone refractory PC-3 prostate cancer cells.

    PubMed

    Lee, Joomin; Ju, Jihyeung; Park, Seyeon; Hong, Sung Joon; Yoon, Sun

    2012-01-01

    Elevated levels of insulin-like growth factor-1 (IGF-1) are associated with an increased risk of several different cancers, including prostate cancer. Inhibition of IGF-1 and the downstream signaling pathways mediated by the activation of the IGF-1 receptor (IGF-1R) may be involved in inhibiting prostate carcinogenesis. We investigated whether genistein downregulated the IGF-1/IGF-1R signaling pathway and inhibited cell growth in hormone refractory PC-3 prostate cancer cells. Genistein treatment caused a significant inhibition of IGF-1-stimulated cell growth. Flow cytometry analysis revealed that genistein significantly decreased the number of IGF-1-stimulated cells in the G0/G1 phase of the cell cycle. In IGF-1-treated cells, genistein effectively inhibited the phosphorylation of IGF-1R and the phosphorylation of its downstream targets, such as Src, Akt, and glycogen synthase kinase-3β (GSk-3β). IGF-1 treatment decreased the levels of E-cadherin but increased the levels of β-catenin and cyclin D1. However, genistein treatment greatly attenuated IGF-1-induced β-catenin signaling that correlated with increasing the levels of E-cadherin and decreasing cyclin D1 levels in PC-3 cells. In addition, genistein inhibited T-cell factor/lymphoid enhancer factor (TCF/LEF)-dependent transcriptional activity. These results showed that genistein effectively inhibited cell growth in IGF-1-stimulated PC-3 cells, possibly by inhibiting downstream of IGF-1R activation.

  4. Genetic dissection of IGF1-dependent and -independent effects of permanent GH excess on postnatal growth and organ pathology of mice.

    PubMed

    Blutke, A; Schneider, M R; Renner-Müller, I; Herbach, N; Wanke, R; Wolf, E

    2014-08-25

    To study insulin-like growth factor 1 (IGF1)-independent effects of permanent growth hormone (GH) excess on body and organ growth and pathology in vivo, hemizygous bovine GH transgenic mice with homozygous disruption of the Igf1 gene (Igf1(-/-)/GH) were generated, and examined in comparison to Igf1(-/-), Igf1(+/-), wild-type (WT), Igf1(+/-)/GH, and GH mice. GH mice and Igf1(+/-)/GH mice showed increased serum IGF1 levels and the well-known giant-phenotype of GH transgenic mice. In contrast, the typical dwarf-phenotype of Igf1(-/-) mice was only slightly ameliorated in Igf1(-/-)/GH mice. Similar to GH mice, Igf1(-/-)/GH mice displayed hepatocellular hypertrophy, glomerulosclerosis, and reduced volumes of acidophilic cells in the pituitary gland. However, GH excess associated skin lesions of male GH mice were not observed in Igf1(-/-)/GH mice. Therefore, development of GH excess induced liver-, kidney-, and pituitary gland-alterations in GH transgenic mice is independent of IGF1 whereas GH stimulated body growth depends on IGF1.

  5. Role of IGF1R+ MSCs in modulating neuroplasticity via CXCR4 cross-interaction

    PubMed Central

    Lee, Hsu-Tung; Chang, Hao-Teng; Lee, Sophie; Lin, Chen-Huan; Fan, Jia-Rong; Lin, Shinn-Zong; Hsu, Chung Y.; Hsieh, Chia-Hung; Shyu, Woei-Cherng

    2016-01-01

    To guide the use of human mesenchymal stem cells (MSCs) toward clinical applications, identifying pluripotent-like-markers for selecting MSCs that retain potent self-renewal-ability should be addressed. Here, an insulin-like growth factor 1 receptor (IGF1R)–expressing sub-population in human dental pulp MSCs (hDSCs), displayed multipotent properties. IGF1R expression could be maintained in hDSCs when they were cultured in 2% human cord blood serum (hUCS) in contrast to that in 10% fetal calf serum (FCS). Cytokine array showed that hUCS contained higher amount of several growth factors compared to FCS, including IGF-1 and platelet-derived growth factor (PDGF-BB). These cytokines modulates the signaling events in the hDSCs and potentially enhances engraftment upon transplantation. Specifically, a bidirectional cross-talk between IGF1R/IGF1 and CXCR4/SDF-1α signaling pathways in hDSCs, as revealed by interaction of the two receptors and synergistic activation of both signaling pathways. In rat stroke model, animals receiving IGF1R+ hDSCs transplantation, interaction between IGF1R and CXCR4 was demonstrated to promote neuroplasticity, therefore improving neurological function through increasing glucose metabolic activity, enhancing angiogenesis and anti-inflammatiory effects. Therefore, PDGF in hUCS-culture system contributed to the maintenance of the expression of IGF1R in hDSCs. Furthermore, implantation of IGF1R+ hDSCs exerted enhanced neuroplasticity via integrating inputs from both CXCR4 and IGF1R signaling pathways. PMID:27586516

  6. IGF-1 Receptor Insufficiency Leads to Age-Dependent Attenuation of Osteoblast Differentiation

    PubMed Central

    Yeh, Lee-Chuan C.; Wilkerson, Matthew; Lee, John C.

    2015-01-01

    In the current study, we determined the effects of IGF-1 receptor haploinsufficiency on osteoblast differentiation and bone formation throughout the lifespan. Bone mineral density was significantly decreased in femurs of male and female Igf1r+/− mice compared with wild-type mice. mRNA expression of osteoblast differentiation markers was significantly decreased in femurs and calvariae from Igf1r+/− mice compared with cells from wild-type mice. Bone morphogenetic protein-7-induced ectopic bone in Igf1r+/− mice was significantly smaller with fewer osteoblasts but more lipid droplets and had reduced expression of osteoblast differentiation markers compared with wild-type mice. In bone marrow cells from middle-aged and old wild-type and Igf1r+/− male mice, palmitate inhibited osteoblast markers expression. In cells from young wild-type male mice, palmitate did not inhibit marker expression, but in cells from young male Igf1r+/− mice, palmitate inhibited bone sialoprotein and osterix but not osteocalcin or type I collagen (TIC). In female wild-type mice, palmitate inhibited osteoblast markers expression in cells from young, middle-aged, and old mice except TIC in cells from middle-aged mice. Palmitate inhibited bone sialoprotein expression in cells from middle-aged and old female Igf1r+/− mice and osteocalcin, osterix, and TIC expression in young and middle-aged female Igf1r+/− mice but stimulated expression in cells from old female Igf1r+/− mice. We conclude that IGF-1 receptor haploinsufficiency results in a prolipid accrual phenotype in bone in association with inhibition of growth factor-induced osteoblast differentiation, a situation which may phenocopy age-related decreases in bone formation. PMID:26076041

  7. How IGF-1 activates its receptor

    PubMed Central

    Kavran, Jennifer M; McCabe, Jacqueline M; Byrne, Patrick O; Connacher, Mary Katherine; Wang, Zhihong; Ramek, Alexander; Sarabipour, Sarvenaz; Shan, Yibing; Shaw, David E; Hristova, Kalina; Cole, Philip A; Leahy, Daniel J

    2014-01-01

    The type I insulin-like growth factor receptor (IGF1R) is involved in growth and survival of normal and neoplastic cells. A ligand-dependent conformational change is thought to regulate IGF1R activity, but the nature of this change is unclear. We point out an underappreciated dimer in the crystal structure of the related Insulin Receptor (IR) with Insulin bound that allows direct comparison with unliganded IR and suggests a mechanism by which ligand regulates IR/IGF1R activity. We test this mechanism in a series of biochemical and biophysical assays and find the IGF1R ectodomain maintains an autoinhibited state in which the TMs are held apart. Ligand binding releases this constraint, allowing TM association and unleashing an intrinsic propensity of the intracellular regions to autophosphorylate. Enzymatic studies of full-length and kinase-containing fragments show phosphorylated IGF1R is fully active independent of ligand and the extracellular-TM regions. The key step triggered by ligand binding is thus autophosphorylation. DOI: http://dx.doi.org/10.7554/eLife.03772.001 PMID:25255214

  8. IGF1 stimulates crypt expansion via differential activation of 2 intestinal stem cell populations.

    PubMed

    Van Landeghem, Laurianne; Santoro, M Agostina; Mah, Amanda T; Krebs, Adrienne E; Dehmer, Jeffrey J; McNaughton, Kirk K; Helmrath, Michael A; Magness, Scott T; Lund, P Kay

    2015-07-01

    Insulin-like growth factor 1 (IGF1) has potent trophic effects on normal or injured intestinal epithelium, but specific effects on intestinal stem cells (ISCs) are undefined. We used Sox9-enhanced green fluorescent protein (EGFP) reporter mice that permit analyses of both actively cycling ISCs (Sox9-EGFP(Low)) and reserve/facultative ISCs (Sox9-EGFP(High)) to study IGF1 action on ISCs in normal intestine or during crypt regeneration after high-dose radiation-induced injury. We hypothesized that IGF1 differentially regulates proliferation and gene expression in actively cycling and reserve/facultative ISCs. IGF1 was delivered for 5 days using subcutaneously implanted mini-pumps in uninjured mice or after 14 Gy abdominal radiation. ISC numbers, proliferation, and transcriptome were assessed. IGF1 increased epithelial growth in nonirradiated mice and enhanced crypt regeneration after radiation. In uninjured and regenerating intestines, IGF1 increased total numbers of Sox9-EGFP(Low) ISCs and percentage of these cells in M-phase. IGF1 increased percentages of Sox9-EGFP(High) ISCs in S-phase but did not expand this population. Microarray revealed that IGF1 activated distinct gene expression signatures in the 2 Sox9-EGFP ISC populations. In vitro IGF1 enhanced enteroid formation by Sox9-EGFP(High) facultative ISCs but not Sox9-EGFP(Low) actively cycling ISCs. Our data provide new evidence that IGF1 activates 2 ISC populations via distinct regulatory pathways to promote growth of normal intestinal epithelium and crypt regeneration after irradiation.

  9. Increased IGF-1 in muscle modulates the phenotype of severe SMA mice.

    PubMed

    Bosch-Marcé, Marta; Wee, Claribel D; Martinez, Tara L; Lipkes, Celeste E; Choe, Dong W; Kong, Lingling; Van Meerbeke, James P; Musarò, Antonio; Sumner, Charlotte J

    2011-05-01

    Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by the mutation of the survival motor neuron 1 (SMN1) gene and deficiency of the SMN protein. Severe SMA mice have abnormal motor function and small, immature myofibers early in development suggesting that SMN protein deficiency results in retarded muscle growth. Insulin-like growth factor 1 (IGF-1) stimulates myoblast proliferation, induces myogenic differentiation and generates myocyte hypertrophy in vitro and in vivo. We hypothesized that increased expression of IGF-1 specifically in skeletal muscle would attenuate disease features of SMAΔ7 mice. SMAΔ7 mice overexpressing a local isoform of IGF-1 (mIGF-1) in muscle showed enlarged myofibers and a 40% increase in median survival compared with mIGF-1-negative SMA littermates (median survival = 14 versus 10 days, respectively, log-rank P = 0.025). Surprisingly, this was not associated with a significant improvement in motor behavior. Treatment of both mIGF-1(NEG) and mIGF-1(POS) SMA mice with the histone deacetylase inhibitor, trichostatin A (TSA), resulted in a further extension of survival and improved motor behavior, but the combination of mIGF-1 and TSA treatment was not synergistic. These results show that increased mIGF-1 expression restricted to muscle can modulate the phenotype of SMA mice indicating that therapeutics targeted to muscle alone should not be discounted as potential disease-modifying therapies in SMA. IGF-1 may warrant further investigation in mild SMA animal models and perhaps SMA patients.

  10. Increased IGF-1 in muscle modulates the phenotype of severe SMA mice

    PubMed Central

    Bosch-Marcé, Marta; Wee, Claribel D.; Martinez, Tara L.; Lipkes, Celeste E.; Choe, Dong W.; Kong, Lingling; Van Meerbeke, James P.; Musarò, Antonio; Sumner, Charlotte J.

    2011-01-01

    Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by the mutation of the survival motor neuron 1 (SMN1) gene and deficiency of the SMN protein. Severe SMA mice have abnormal motor function and small, immature myofibers early in development suggesting that SMN protein deficiency results in retarded muscle growth. Insulin-like growth factor 1 (IGF-1) stimulates myoblast proliferation, induces myogenic differentiation and generates myocyte hypertrophy in vitro and in vivo. We hypothesized that increased expression of IGF-1 specifically in skeletal muscle would attenuate disease features of SMAΔ7 mice. SMAΔ7 mice overexpressing a local isoform of IGF-1 (mIGF-1) in muscle showed enlarged myofibers and a 40% increase in median survival compared with mIGF-1-negative SMA littermates (median survival = 14 versus 10 days, respectively, log-rank P = 0.025). Surprisingly, this was not associated with a significant improvement in motor behavior. Treatment of both mIGF-1NEG and mIGF-1POS SMA mice with the histone deacetylase inhibitor, trichostatin A (TSA), resulted in a further extension of survival and improved motor behavior, but the combination of mIGF-1 and TSA treatment was not synergistic. These results show that increased mIGF-1 expression restricted to muscle can modulate the phenotype of SMA mice indicating that therapeutics targeted to muscle alone should not be discounted as potential disease-modifying therapies in SMA. IGF-1 may warrant further investigation in mild SMA animal models and perhaps SMA patients. PMID:21325354

  11. Growth hormone mediates pubertal skeletal development independent of hepatic IGF-1 production.

    PubMed

    Courtland, Hayden-William; Sun, Hui; Beth-On, Mordechay; Wu, Yingjie; Elis, Sebastien; Rosen, Clifford J; Yakar, Shoshana

    2011-04-01

    Deficiencies in either growth hormone (GH) or insulin-like growth factor 1 (IGF-1) are associated with reductions in bone size during growth in humans and animal models. Liver-specific IGF-1-deficient (LID) mice, which have 75% reductions in serum IGF-1, were created previously to separate the effects of endocrine (serum) IGF-1 from autocrine/paracrine IGF-1. However, LID mice also have two- to threefold increases in GH, and this may contribute to the observed pubertal skeletal phenotype. To clarify the role of GH in skeletal development under conditions of significantly reduced serum IGF-1 levels (but normal tissue IGF-1 levels), we studied the skeletal response of male LID and control mice to GH inhibition by pegvisomant from 4 to 8 weeks of age. Treatment of LID mice with pegvisomant resulted in significant reductions in body weight, femur length (Le), and femur total area (Tt.Ar), as well as further reductions in serum IGF-1 levels by 8 weeks of age, compared with the mean values of vehicle-treated LID mice. Reductions in both Tt.Ar and Le were proportional after treatment with pegvisomant. On the other hand, the relative amount of cortical tissue formed (RCA) in LID mice treated with pegvisomant was significantly less than that in both vehicle-treated LID and control mice, indicating that antagonizing GH action, either directly (through GH receptor signaling inhibition) or indirectly (through further reductions in serum/tissue IGF-1 levels), results in disproportionate reductions in the amount of cortical bone formed. This resulted in bones with significantly reduced mechanical properties (femoral whole-bone stiffness and work to failure were markedly decreased), suggesting that compensatory increases of GH in states of IGF-1 deficiency (LID mice) act to protect against a severe inhibition of bone modeling during growth, which otherwise would result in bones that are too weak for normal and/or extreme loading conditions.

  12. The GH-IGF1 axis and longevity. The paradigm of IGF1 deficiency.

    PubMed

    Laron, Zvi

    2008-01-01

    Primary or secondary IGF1 deficiency has been implicated in shortening of lifespan. This paper reviews available data on the influence of IGF1 deficiency on lifespan and longevity in animals and man. It has been shown that inactivation of the IGF1 gene or of the GH receptor in both invertebrates (C-elegans, flies-Drosphila) and rodents (mice and rats), leading to IGF1 deficiency, prolong life, particularly in females. In man, evaluation of the 2 largest cohorts of patients with Laron syndrome (inactive GH receptor resulting in IGF1 deficiency) in Israel and Ecuador revealed that despite their dwarfism and marked obesity, patients are alive at the ages of 75-78 years, with some having reached even more advanced ages. It is assumed that a major contributing factor is their protection from cancer, a major cause of death in the general population.

  13. A Novel Role of IGF1 in Apo2L/TRAIL-Mediated Apoptosis of Ewing Tumor Cells.

    PubMed

    van Valen, Frans; Harrer, Henning; Hotfilder, Marc; Dirksen, Uta; Pap, Thomas; Gosheger, George; Humpf, Hans-Ulrich; Jürgens, Heribert

    2012-01-01

    Insulin-like growth factor 1 (IGF1) reputedly opposes chemotoxicity in Ewing sarcoma family of tumor (ESFT) cells. However, the effect of IGF1 on apoptosis induced by apoptosis ligand 2 (Apo2L)/tumor necrosis factor (TNF-) related apoptosis-inducing ligand (TRAIL) remains to be established. We find that opposite to the partial survival effect of short-term IGF1 treatment, long-term IGF1 treatment amplified Apo2L/TRAIL-induced apoptosis in Apo2L/TRAIL-sensitive but not resistant ESFT cell lines. Remarkably, the specific IGF1 receptor (IGF1R) antibody α-IR3 was functionally equivalent to IGF1. Short-term IGF1 incubation of cells stimulated survival kinase AKT and increased X-linked inhibitor of apoptosis (XIAP) protein which was associated with Apo2L/TRAIL resistance. In contrast, long-term IGF1 incubation resulted in repression of XIAP protein through ceramide (Cer) formation derived from de novo synthesis which was associated with Apo2L/TRAIL sensitization. Addition of ceramide synthase (CerS) inhibitor fumonisin B1 during long-term IGF1 treatment reduced XIAP repression and Apo2L/TRAIL-induced apoptosis. Noteworthy, the resistance to conventional chemotherapeutic agents was maintained in cells following chronic IGF1 treatment. Overall, the results suggest that chronic IGF1 treatment renders ESFT cells susceptible to Apo2L/TRAIL-induced apoptosis and may have important implications for the biology as well as the clinical management of refractory ESFT.

  14. A Novel Role of IGF1 in Apo2L/TRAIL-Mediated Apoptosis of Ewing Tumor Cells

    PubMed Central

    van Valen, Frans; Harrer, Henning; Hotfilder, Marc; Dirksen, Uta; Pap, Thomas; Gosheger, George; Humpf, Hans-Ulrich; Jürgens, Heribert

    2012-01-01

    Insulin-like growth factor 1 (IGF1) reputedly opposes chemotoxicity in Ewing sarcoma family of tumor (ESFT) cells. However, the effect of IGF1 on apoptosis induced by apoptosis ligand 2 (Apo2L)/tumor necrosis factor (TNF-) related apoptosis-inducing ligand (TRAIL) remains to be established. We find that opposite to the partial survival effect of short-term IGF1 treatment, long-term IGF1 treatment amplified Apo2L/TRAIL-induced apoptosis in Apo2L/TRAIL-sensitive but not resistant ESFT cell lines. Remarkably, the specific IGF1 receptor (IGF1R) antibody α-IR3 was functionally equivalent to IGF1. Short-term IGF1 incubation of cells stimulated survival kinase AKT and increased X-linked inhibitor of apoptosis (XIAP) protein which was associated with Apo2L/TRAIL resistance. In contrast, long-term IGF1 incubation resulted in repression of XIAP protein through ceramide (Cer) formation derived from de novo synthesis which was associated with Apo2L/TRAIL sensitization. Addition of ceramide synthase (CerS) inhibitor fumonisin B1 during long-term IGF1 treatment reduced XIAP repression and Apo2L/TRAIL-induced apoptosis. Noteworthy, the resistance to conventional chemotherapeutic agents was maintained in cells following chronic IGF1 treatment. Overall, the results suggest that chronic IGF1 treatment renders ESFT cells susceptible to Apo2L/TRAIL-induced apoptosis and may have important implications for the biology as well as the clinical management of refractory ESFT. PMID:23091403

  15. GRK2 negatively regulates IGF-1R signaling pathway and cyclins' expression in HepG2 cells.

    PubMed

    Wei, Zhengyu; Hurtt, Reginald; Gu, Tina; Bodzin, Adam S; Koch, Walter J; Doria, Cataldo

    2013-09-01

    G protein coupled receptor kinase 2 (GRK2) plays a central role in the regulation of a variety of important signaling pathways. Alternation of GRK2 protein level and activity casts profound effects on cell physiological functions and causes diseases such as heart failure, rheumatoid arthritis, and obesity. We have previously reported that overexpression of GRK2 has an inhibitory role in cancer cell growth. To further examine the role of GRK2 in cancer, in this study, we investigated the effects of reduced protein level of GRK2 on insulin-like growth factor 1 receptor (IGF-1R) signaling pathway in human hepatocellular carcinoma (HCC) HepG2 cells. We created a GRK2 knockdown cell line using a lentiviral vector mediated expression of GRK2 specific short hairpin RNA (shRNA). Under IGF-1 stimulation, HepG2 cells with reduced level of GRK2 showed elevated total IGF-1R protein expression as well as tyrosine phosphorylation of receptor. In addition, HepG2 cells with reduced level of GRK2 also demonstrated increased tyrosine phosphorylation of IRS1 at the residue 612 and increased phosphorylation of Akt, indicating a stronger activation of IGF-1R signaling pathway. However, HepG2 cells with reduced level of GRK2 did not display any growth advantage in culture as compared with the scramble control cells. We further detected that reduced level of GRK2 induced a small cell cycle arrest at G2/M phase by enhancing the expression of cyclin A, B1, and E. Our results indicate that GRK2 has contrasting roles on HepG2 cell growth by negatively regulating the IGF-1R signaling pathway and cyclins' expression.

  16. Intraplacental Gene Therapy with Ad-IGF-1 Corrects Naturally Occurring Rabbit Model of Intrauterine Growth Restriction

    PubMed Central

    Keswani, Sundeep G.; Balaji, Swathi; Katz, Anna B.; King, Alice; Omar, Khaled; Habli, Mounira; Klanke, Charles

    2015-01-01

    Abstract Intrauterine growth restriction (IUGR) due to placental insufficiency is a leading cause of perinatal complications for which there is no effective prenatal therapy. We have previously demonstrated that intraplacental injection of adenovirus-mediated insulin-like growth factor-1 (Ad-IGF-1) corrects fetal weight in a murine IUGR model induced by mesenteric uterine artery branch ligation. This study investigated the effect of intraplacental Ad-IGF-1 gene therapy in a rabbit model of naturally occurring IUGR (runt) due to placental insufficiency, which is similar to the human IUGR condition with onset in the early third trimester, brain sparing, and a reduction in liver weight. Laparotomy was performed on New Zealand White rabbits on day 21 of 30 days of gestation and litters were divided into five groups: Control (first position)+phosphate-buffered saline (PBS), control+Ad-IGF-1, runt (third position)+PBS, runt+Ad-IGF-1, and runt+Ad-LacZ. The effect of IGF-1 gene therapy on fetal, placental, liver, heart, lung, and musculoskeletal weights of the growth-restricted pups was examined. Protein expression after gene transfer was seen along the maternal–fetal placenta interface (n=12) 48 hr after gene therapy. There was minimal gene transfer detected in the pups or maternal organs. At term, compared with the normally grown first-position control, the runted third-position pups demonstrated significantly lower fetal, placental, liver, lung, and musculoskeletal weights. The fetal, liver, and musculoskeletal weights were restored to normal by intraplacental Ad-IGF-1 gene therapy (p<0.01), with no change in the placental weight. Intraplacental gene therapy is a novel strategy for the treatment of IUGR caused by placental insufficiency that takes advantage of an organ that will be discarded at birth. Development of nonviral IGF-1 gene delivery using placenta-specific promoters can potentially minimize toxicity to the mother and fetus and facilitate clinical

  17. Phase I study of humanized monoclonal antibody AVE1642 directed against the type 1 insulin-like growth factor receptor (IGF-1R), administered in combination with anticancer therapies to patients with advanced solid tumors

    PubMed Central

    Macaulay, V. M.; Middleton, M. R.; Protheroe, A. S.; Tolcher, A.; Dieras, V.; Sessa, C.; Bahleda, R.; Blay, J.-Y.; LoRusso, P.; Mery-Mignard, D.; Soria, J.-C.

    2013-01-01

    Background Type 1 insulin-like growth factor receptor (IGF-1R) mediates resistance to chemotherapy and targeted agents. This study assessed the safety, pharmacokinetics (PK), and tolerability of humanized IGF-1R antibody AVE1642 with other cancer treatments. Patients Patients with advanced solid tumors received three weekly AVE1642 dosed at 6 mg/kg, chosen following previous study, with 75 (cohort A) or 100 mg/m2 (B) docetaxel, 1250 mg/m2 gemcitabine/100 mg erlotinib (C1), or 60 mg/m2 doxorubicin (D1). Blood samples were assayed for PK, IGFs, and IGF-BP3. Results Fifty-eight patients received 317 AVE1642 infusions. The commonest adverse events were diarrhea (37/58 patients), asthenia (34/58), nausea (30/58), and stomatitis (21/58). Dose-limiting toxic effects in cohorts C1 (diarrhea) and D1 (neutropenia) prompted addition of cohorts C2 (1000 mg/m2 gemcitabine/75 mg erlotinib) and D2 (50 mg/m2 doxorubicin). Grade 3–4 hyperglycemia (three cases) accompanied steroid premedication for docetaxel administration. No PK interactions were detected. There were three partial responses in cohorts B (melanoma) and C (leiomyosarcoma, two cases) and 22 stabilizations ≥12 weeks, giving a control rate of 25/57 (44%). On treatment IGF-II rose by 68 ± 25 ng/ml in patients discontinuing treatment <12 weeks, and fell by 55.5 ± 21 ng/ml with disease control (P < 0.001). Conclusion AVE1642 was tolerable with 75–100 mg/m2 docetaxel and 1000 mg/m2 gemcitabine/75 mg erlotinib, achieving durable disease control in 44%, with an association between IGF-II and response. PMID:23104723

  18. The molecular responses of skeletal muscle satellite cells to continuous expression of IGF-1: implications for the rescue of induced muscular atrophy in aged rats

    NASA Technical Reports Server (NTRS)

    Chakravarthy, M. V.; Booth, F. W.; Spangenburg, E. E.

    2001-01-01

    Approximately 50% of humans older than 85 years have physical frailty due to weak skeletal muscles. This indicates a need for determining mechanisms to combat this problem. A critical cellular factor for postnatal muscle growth is a population of myogenic precursor cells called satellite cells. Given the complex process of sarcopenia, it has been postulated that, at some point in this process, a limited satellite cell proliferation potential could become rate-limiting to the regrowth of old muscles. It is conceivable that if satellite cell proliferative capacity can be maintained or enhanced with advanced age, sarcopenia could potentially be delayed or prevented. Therefore, the purposes of this paper are to describe whether IGF-I can prevent muscular atrophy induced by repeated cycles of hindlimb immobilization, increase the in vitro proliferation in satellite cells from these muscles and, if so, the molecular mechanisms by which IGF-I mediates this increased proliferation. Our results provide evidence that IGF-I can enhance aged muscle regrowth possibly through increased satellite cell proliferation. The results also suggest that IGF-I enhances satellite cell proliferation by decreasing the cell cycle inhibitor, p27Kip1, through the PI3'-K/Akt pathway. These data provide molecular evidence for IGF-I's rescue effect upon aging-associated skeletal muscle atrophy.

  19. Long-term deficiency of circulating and hippocampal insulin-like growth factor I induces depressive behavior in adult mice: A potential model of geriatric depression

    PubMed Central

    Mitschelen, Matthew; Yan, Han; Farley, Julie A.; Warrington, Junie P.; Han, Song; Hereñú, Claudia B.; Csiszar, Anna; Ungvari, Zoltan; Bailey-Downs, Lora C.; Bass, Caroline E.; Sonntag, William E.

    2011-01-01

    Numerous studies support the hypothesis that deficiency of insulin-like growth factor I (IGF-1) in adults contributes to depression, but direct evidence is limited. Many psychological and pro-cognitive effects have been attributed to IGF-1, but appropriate animal models of adult-onset IGF-1 deficiency are lacking. In this study, we use a viral-mediated Cre-loxP system to knockout the Igf1 gene in either the liver, neurons of the CA1 region of the hippocampus, or both. Knockout of liver Igf1 reduced serum IGF-1 levels by 40% and hippocampal IGF-1 levels by 26%. Knockout of Igf1 in CA1 reduced hippocampal IGF-1 levels by 13%. The most severe reduction in hippocampal IGF-1 occurred in the group with knockouts in both liver and CA1 (36% reduction), and was associated with a 3.5-fold increase in immobility in the forced swim test. Reduction of either circulating or hippocampal IGF-1 levels did not alter anxiety measured in an open field and elevated plus maze, nor locomotion in the open field. Furthermore, local compensation for deficiencies in circulating IGF-1 did not occur in the hippocampus, nor were serum levels of IGF-1 upregulated in response to the moderate decline of hippocampal IGF-1 caused by the knockouts in CA1. We conclude that adult-onset IGF-1 deficiency alone is sufficient to induce a depressive phenotype in mice. Furthermore, our results suggest that individuals with low brain levels of IGF-1 are at increased risk for depression and these behavioral effects are not ameliorated by increased local IGF-1 production or transport. Our study supports the hypothesis that the natural IGF-1 decline in aging humans may contribute to geriatric depression. PMID:21524689

  20. Resveratrol inhibits collagen I synthesis by suppressing IGF-1R activation in intestinal fibroblasts

    PubMed Central

    Li, Ping; Liang, Mei-Lan; Zhu, Ying; Gong, Yao-Yao; Wang, Yun; Heng, Ding; Lin, Lin

    2014-01-01

    AIM: To investigate whether resveratrol (3,4,5-trihydroxy-trans-stilbene) inhibits collagen I synthesis induced by insulin growth factor-1 (IGF-1) in intestinal fibroblasts, and to explore the possible molecular mechanisms. METHODS: Male Sprague-Dawley rats were randomly divided into two groups: a control group and a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis group. After 21 d of TNBS administration, the degree of inflammation and fibrosis in colon was measured by HE staining and Masson’s trichrome staining. Western blotting was used to examine collagen I, IGF-1 and silent information regulator 1 (SIRT1) protein expression in colitis tissues. Western blotting and quantitative real-time polymerase chain reaction were used to characterize collagen I protein and col1a2 mRNA expression in mouse intestinal fibroblasts and CCD-18Co cells treated with IGF-1. A MEK inhibitor (U0126) was used to determine whether IGF-1-induced collagen I expression was mediated by extracellular signal-regulated kinase 1/2 (ERK1/2)-dependent mechanism. Effects of resveratrol on collagen I protein level, insulin growth factor-1 receptor (IGF-1R) and ERK1/2 phosphorylation levels were also examined after IGF-1 treatment in fibroblasts. To evaluate whether SIRT1 was necessary for the anti-fibrosis effect of resveratrol, cells were transfected with SIRT1-specific small interfering RNAs, wild-type SIRT1, and deacetylase-inactive mutant SIRT1. RESULTS: Collagen I and IGF-1 expression was increased, and SIRT1 expression was decreased (0.67 ± 0.04 vs 1.05 ± 0.07, P < 0.001) in TNBS-induced colitis compared with the control group. In vitro, IGF-1 could induce collagen I expression, mainly through the ERK 1/2 signal pathway. Resveratrol reduced basal and IGF-1-induced collagen I gene and protein expression in intestinal fibroblasts. Overexpression of wild-type SIRT1, not deacetylase-inactive mutant SIRT1, decreased expression of collagen I induced

  1. Correlation between GH and IGF-1 during treatment for acromegaly.

    PubMed

    Oldfield, Edward H; Jane, John A; Thorner, Michael O; Pledger, Carrie L; Sheehan, Jason P; Vance, Mary Lee

    2016-11-18

    OBJECTIVE The relationship between growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in patients with acromegaly as serial levels drop over time after treatment has not been examined previously. Knowledge of this relationship is important to correlate pretreatment levels that best predict response to treatment. To examine the correlation between GH and IGF-1 and IGF-1 z-scores over a wide range of GH levels, the authors examined serial GH and IGF-1 levels at intervals before and after surgery and radiosurgery for acromegaly. METHODS This retrospective analysis correlates 414 pairs of GH and IGF-1 values in 93 patients with acromegaly. RESULTS Absolute IGF-1 levels increase linearly with GH levels only up to a GH of 4 ng/ml, and with IGF-1 z-scores only to a GH level of 1 ng/ml. Between GH levels of 1 and 10 ng/ml, increases in IGF-1 z-scores relative to changes in GH diminish and then plateau at GH concentrations of about 10 ng/ml. From patient to patient there is a wide range of threshold GH levels beyond which IGF-1 increases are no longer linear, GH levels at which the IGF-1 response plateaus, IGF-1 levels at similar GH values after the IGF-1 response plateaus, and of IGF-1 levels at similar GH levels. CONCLUSIONS In acromegaly, although IGF-1 levels represent a combination of the integrated effects of GH secretion and GH action, the tumor produces GH, not IGF-1. Nonlinearity between GH and IGF-1 occurs at GH levels far below those previously recognized. To monitor tumor activity and tumor viability requires measurement of GH levels.

  2. Increased cardiogenesis in P19-GFP teratocarcinoma cells expressing the propeptide IGF-1Ea

    SciTech Connect

    Poudel, Bhawana; Bilbao, Daniel; Sarathchandra, Padmini; Germack, Renee; Rosenthal, Nadia; Santini, Maria Paola

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer In this study, we explored the function of IGF-1Ea propeptide in inducing cardiogenesis of stem cells. Black-Right-Pointing-Pointer IGF-1Ea promoted cardiac mesodermal induction in uncommitted cells. Black-Right-Pointing-Pointer Under differentiation condition, IGF-1Ea increased expression of cardiac differentiation markers. Black-Right-Pointing-Pointer Furthermore, it promoted formation of finely organized sarcomeric structure. Black-Right-Pointing-Pointer IGF-1Ea propeptide may be a good candidate to improve production of cardiomyocytes from pluripotent cells. -- Abstract: The mechanism implicated in differentiation of endogenous cardiac stem cells into cardiomyocytes to regenerate the heart tissue upon an insult remains elusive, limiting the therapeutical goals to exogenous cell injection and/or gene therapy. We have shown previously that cardiac specific overexpression of the insulin-like growth factor 1 propeptide IGF-1Ea induces beneficial myocardial repair after infarct. Although the mechanism is still under investigation, the possibility that this propeptide may be involved in promoting stem cell differentiation into the cardiac lineage has yet to be explored. To investigate whether IGF-1Ea promote cardiogenesis, we initially modified P19 embryonal carcinoma cells to express IGF-1Ea. Taking advantage of their cardiomyogenic nature, we analyzed whether overexpression of this propeptide affected cardiac differentiation program. The data herein presented showed for the first time that constitutively overexpressed IGF-1Ea increased cardiogenic differentiation program in both undifferentiated and DMSO-differentiated cells. In details, IGF-1Ea overexpression promoted localization of alpha-actinin in finely organized sarcomeric structure compared to control cells and upregulated the cardiac mesodermal marker NKX-2.5 and the ventricular structural protein MLC2v. Furthermore, activated IGF-1 signaling promoted cardiac

  3. Local IGF-1 isoform protects cardiomyocytes from hypertrophic and oxidative stresses via SirT1 activity.

    PubMed

    Vinciguerra, Manlio; Santini, Maria Paola; Claycomb, William C; Ladurner, Andreas G; Rosenthal, Nadia

    2009-12-10

    Oxidative and hypertrophic stresses contribute to the pathogenesis of heart failure. Insulin-like growth factor-1 (IGF-1) is a peptide hormone with a complex post-transcriptional regulation, generating distinct isoforms. Locally acting IGF-1 isoform (mIGF-1) helps the heart to recover from toxic injury and from infarct. In the murine heart, moderate overexpression of the NAD(+)-dependent deacetylase SirT1 was reported to mitigate oxidative stress. SirT1 is known to promote lifespan extension and to protect from metabolic challenges. Circulating IGF-1 and SirT1 play antagonizing biological roles and share molecular targets in the heart, in turn affecting cardiomyocyte physiology. However, how different IGF-1 isoforms may impact SirT1 and affect cardiomyocyte function is unknown. Here we show that locally acting mIGF-1 increases SirT1 expression/activity, whereas circulating IGF-1 isoform does not affect it, in cultured HL-1 and neonatal cardiomyocytes. mIGF-1-induced SirT1 activity exerts protection against angiotensin II (Ang II)-triggered hypertrophy and against paraquat (PQ) and Ang II-induced oxidative stress. Conversely, circulating IGF-1 triggered itself oxidative stress and cardiomyocyte hypertrophy. Interestingly, potent cardio-protective genes (adiponectin, UCP-1 and MT-2) were increased specifically in mIGF-1-overexpressing cardiomyocytes, in a SirT1-dependent fashion. Thus, mIGF-1 protects cardiomyocytes from oxidative and hypertrophic stresses via SirT1 activity, and may represent a promising cardiac therapeutic.

  4. ERK phosphorylation is predictive of resistance to IGF-1R inhibition in small cell lung cancer.

    PubMed

    Zinn, Rebekah L; Gardner, Eric E; Marchionni, Luigi; Murphy, Sara C; Dobromilskaya, Irina; Hann, Christine L; Rudin, Charles M

    2013-06-01

    New therapies are critically needed to improve the outcome for patients with small cell lung cancer (SCLC). Insulin-like growth factor 1 receptor (IGF-1R) inhibition is a potential treatment strategy for SCLC: the IGF-1R pathway is commonly upregulated in SCLC and has been associated with inhibition of apoptosis and stimulation of proliferation through downstream signaling pathways, including phosphatidylinositol-3-kinase-Akt and mitogen-activated protein kinase. To evaluate potential determinants of response to IGF-1R inhibition, we assessed the relative sensitivity of 19 SCLC cell lines to OSI-906, a small molecule inhibitor of IGF-1R, and the closely related insulin receptor. Approximately one third of these cell lines were sensitive to OSI-906, with an IC50 < 1 μmol/L. Cell line expression of IGF-1R, IR, IGF-1, IGF-2, IGFBP3, and IGFBP6 did not correlate with sensitivity to OSI-906. Interestingly, OSI-906 sensitive lines expressed significantly lower levels of baseline phospho-ERK relative to resistant lines (P = 0.006). OSI-906 treatment resulted in dose-dependent inhibition of phospho-IGF-1R and phospho-Akt in both sensitive and resistant cell lines, but induced apoptosis and cell-cycle arrest only in sensitive lines. We tested the in vivo efficacy of OSI-906 using an NCI-H187 xenograft model and two SCLC patient xenografts in mice. OSI-906 treatment resulted in 50% tumor growth inhibition in NCI-H187 and 30% inhibition in the primary patient xenograft models compared with mock-treated animals. Taken together our data support IGF-1R inhibition as a viable treatment strategy for a defined subset of SCLC and suggest that low pretreatment levels of phospho-ERK may be indicative of sensitivity to this therapeutic approach.

  5. IGF-1 potentiates sensory innervation signalling by modulating the mitochondrial fission/fusion balance

    PubMed Central

    Ding, Yuan; Li, Jianmin; Liu, Zhen; Liu, Huaxiang; Li, Hao; Li, Zhenzhong

    2017-01-01

    Restoring the contractile function of long-term denervated skeletal muscle (SKM) cells is difficult due to the long period of denervation, which causes a loss of contractility. Although sensory innervation is considered a promising protective approach, its effect is still restricted. In this study, we introduced insulin-like growth factor-1 (IGF-1) as an efficient protective agent and observed that IGF-1 potentiated the effects of sensory protection by preventing denervated muscle atrophy and improving the condition of denervated muscle cells in vivo and in vitro. IGF-1-induced Akt phosphorylation suppressed the mitochondrial outer-membrane protein Mul1 expression, which is a key step on preserving contractile property of sensory innervated SKM cells. Mul1 overexpression interfered with the balance between mitochondrial fusion and fission and was a key node for blocking the effects of IGF-1 that preserved the contractility of sensory-innervated SKM cells. Activation of AMP-activated protein kinase α (AMPKα), a mitochondrial downstream target, could block the effects of IGF-1. These data provide novel evidence that might be applied when searching for new approaches to improve the functional condition of long-term denervated SKM cells by increasing sensory protection using the IGF-1 signalling system to modulate the balance between mitochondrial fusion and fission. PMID:28276453

  6. Insulin and IGF-1 regularize energy metabolites in neural cells expressing full-length mutant huntingtin.

    PubMed

    Naia, Luana; Ribeiro, Márcio; Rodrigues, Joana; Duarte, Ana I; Lopes, Carla; Rosenstock, Tatiana R; Hayden, Michael R; Rego, A Cristina

    2016-08-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder linked to the expression of mutant huntingtin. Bioenergetic dysfunction has been described to contribute to HD pathogenesis. Thus, treatment paradigms aimed to ameliorate energy deficits appear to be suitable candidates in HD. In previous studies, we observed protective effects of insulin growth factor-1 (IGF-1) in YAC128 and R6/2 mice, two HD mouse models, whereas IGF-1 and/or insulin halted mitochondrial-driven oxidative stress in mutant striatal cells and mitochondrial dysfunction in HD human lymphoblasts. Here, we analyzed the effect of IGF-1 versus insulin on energy metabolic parameters using striatal cells derived from HD knock-in mice and primary cortical cultures from YAC128 mice. STHdh(Q111/Q111) cells exhibited decreased ATP/ADP ratio and increased phosphocreatine levels. Moreover, pyruvate levels were increased in mutant cells, most probably in consequence of a decrease in pyruvate dehydrogenase (PDH) protein expression and increased PDH phosphorylation, reflecting its inactivation. Insulin and IGF-1 treatment significantly decreased phosphocreatine levels, whereas IGF-1 only decreased pyruvate levels in mutant cells. In a different scenario, primary cortical cultures derived from YAC128 mice also displayed energetic abnormalities. We observed a decrease in both ATP/ADP and phosphocreatine levels, which were prevented following exposure to insulin or IGF-1. Furthermore, decreased lactate levels in YAC128 cultures occurred concomitantly with a decline in lactate dehydrogenase activity, which was ameliorated with both insulin and IGF-1. These data demonstrate differential HD-associated metabolic dysfunction in striatal cell lines and primary cortical cultures, both of which being alleviated by insulin and IGF-1.

  7. rhIGF-1 Therapy for Growth Failure and IGF-1 Deficiency in Congenital Disorder of Glycosylation Ia (PMM2 Deficiency)

    PubMed Central

    Duffy, Meghann M.; Addo, O. Yaw; Sarafoglou, Kyriakie

    2013-01-01

    Background. Congenital disorders of glycosylation (CDG) are a group of rare disorders in which glycosylation required for proper protein-protein interactions and protein stability is disrupted, manifesting clinically with multiple system involvement and growth failure. The insulin-like growth factor (IGF) system plays an important role in childhood growth and has been shown to be dysfunctional with low IGF-1 levels in children with CDG type Ia (PMM2 deficiency). Case report. A 3-year-old Caucasian male with failure to thrive was diagnosed with PMM2-CDG at 5 months of age. Initially, his length and weight were less than −2 standard deviation score, IGF-1 <25 ng/mL (normal 55-327 ng/mL), IGFBP-3 1.0 µg/mL (normal 0.7-3.6 ng/mL), and acid-labile subunit 1.3 mg/L (normal 0.7-7.9 mg/L). Despite aggressive feeding, he continued to show poor linear growth and weight gain. At 17 months, he underwent an IGF-1 generation test with growth hormone (0.1 mg/kg/d) for 7 days; baseline IGF-1of 27 ng/mL (normal 55-327 ng/mL) stimulated to only 33 ng/mL. Recombinant human IGF-1 (rhIGF-1) therapy (up to 130 µg/kg/dose twice daily) was initiated at 21 months of age resulting in an excellent linear growth response with height increasing from −2.73 to −1.39 standard deviation score over 22 months. IGF-1 and IGFBP-3 levels also increased. Conclusion. This is the first case report of rhIGF-1 therapy in a patient with PMM2-CDG. The child had an excellent linear growth response. These results provide additional in vivo evidence for IGF dysfunction in PMM2-CDG and suggest that rhIGF-1 may be a novel treatment for growth failure in PMM2-CDG. PMID:26425584

  8. New insights into IGF-1 signaling in the heart.

    PubMed

    Troncoso, Rodrigo; Ibarra, Cristián; Vicencio, Jose Miguel; Jaimovich, Enrique; Lavandero, Sergio

    2014-03-01

    Insulin-like growth factor 1 (IGF-1) signaling regulates contractility, metabolism, hypertrophy, autophagy, senescence, and apoptosis in the heart. IGF-1 deficiency is associated with an increased risk of cardiovascular disease, whereas cardiac activation of IGF-1 receptor (IGF-1R) protects from the detrimental effects of a high-fat diet and myocardial infarction. IGF-1R activates multiple pathways through its intrinsic tyrosine kinase activity and through coupling to heterotrimeric G protein. These pathways involve classic second messengers, phosphorylation cascades, lipid signaling, Ca(2+) transients, and gene expression. In addition, IGF-1R triggers signaling in different subcellular locations including the plasma membrane, perinuclear T tubules, and also in internalized vesicles. In this review, we provide a fresh and updated view of the complex IGF-1 scenario in the heart, including a critical focus on therapeutic strategies.

  9. Pancreatic Fibroblasts Stimulate the Motility of Pancreatic Cancer Cells through IGF1/IGF1R Signaling under Hypoxia

    PubMed Central

    Hirakawa, Toshiki; Yashiro, Masakazu; Doi, Yosuke; Kinoshita, Haruhito; Morisaki, Tamami; Fukuoka, Tatsunari; Hasegawa, Tsuyoshi; Kimura, Kenjiro; Amano, Ryosuke; Hirakawa, Kosei

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is characterized by its hypovascularity, with an extremely poor prognosis because of its highly invasive nature. PDAC proliferates with abundant stromal cells, suggesting that its invasive activity might be controlled by intercellular interactions between cancer cells and fibroblasts. Using four PDAC cell lines and two pancreas cancer-associated fibroblasts (CAFs), the expression of insulin-like growth factor-1 (IGF1) and IGF1 receptor (IGF1R) was evaluated by RT-PCR, FACScan, western blot, or ELISA. Correlation between IGF1R and the hypoxia marker carbonic anhydrase 9 (CA9) was examined by immunohistochemical staining of 120 pancreatic specimens. The effects of CAFs, IGF1, and IGF1R inhibitors on the motility of cancer cells were examined by wound-healing assay or invasion assay under normoxia (20% O2) and hypoxia (1% O2). IGF1R expression was significantly higher in RWP-1, MiaPaCa-2, and OCUP-AT cells than in Panc-1 cells. Hypoxia increased the expression level of IGF1R in RWP-1, MiaPaCa-2, and OCUP-AT cells. CA9 expression was correlated with IGF1R expression in pancreatic specimens. CAFs produced IGF1 under hypoxia, but PDAC cells did not. A conditioned medium from CAFs, which expressed αSMA, stimulated the migration and invasion ability of MiaPaCa-2, RWP-1, and OCUP-AT cells. The motility of all PDAC cells was greater under hypoxia than under normoxia. The motility-stimulating ability of CAFs was decreased by IGF1R inhibitors. These findings might suggest that pancreas CAFs stimulate the invasion activity of PDAC cells through paracrine IGF1/IGF1R signaling, especially under hypoxia. Therefore the targeting of IGF1R signaling might represent a promising therapeutic approach in IGF1R-dependent PDAC. PMID:27487118

  10. Metformin Enhances the Therapy Effects of Anti-IGF-1R mAb Figitumumab to NSCLC

    PubMed Central

    Cao, Hongxin; Dong, Wei; Qu, Xiao; Shen, Hongchang; Xu, Jun; Zhu, Linhai; Liu, Qi; Du, Jiajun

    2016-01-01

    The insulin-like growth factor (IGF) signaling system plays a critical role in tumorigenesis, highlighting the potential of targeting IGF-1R as an anti-cancer therapy. Although multiple anti-IGF-1R monoclonal antibody (mAb) drugs have been developed, challenges remain in the validation of the therapeutic effects and understanding the molecular mechanism of these mAbs. Herein, we conducted a study to validate the effect of Figitumumab (CP), an anti-IGF-1R mAb, in a panel of non-small cell lung cancer (NSCLC) cell lines. We found all tested cell lines were sensitive to CP, and CP could block IGF-1R and the downstream PI3K/AKT pathway activation. Unexpectedly, we found CP could activate ERK signaling pathway in IGF-1R kinase independent manner, which we further verified was mainly mediated by β-arrestin2. We also investigated the anti-tumor effect of metformin alone as well as its combination with CP to target NSCLC. Metformin could target IGF-1R signaling pathway by attenuating PI3K/AKT and MEK/ERK signaling pathways and down-regulating IGF-1R. Finally, we found that combining metformin with CP could further induce IGF-1R down-regulation and was more effective to target NSCLC cells. Our data suggests the combining of metformin with CP has additive therapeutic value against NSCLC. PMID:27488947

  11. miR-483 is Down-Regulated in Polycystic Ovarian Syndrome and Inhibits KGN Cell Proliferation via Targeting Insulin-Like Growth Factor 1 (IGF1)

    PubMed Central

    Xiang, Yungai; Song, Yuxia; Li, Yan; Zhao, Dongmei; Ma, Liying; Tan, Li

    2016-01-01

    Background Polycystic ovarian syndrome (PCOS) is a common metabolic disorder in premenopausal woman, characterized by hyperandrogenism, oligoanovulation, and insulin resistance. microRNAs play pivotal roles in regulating key factors of PCOS. However, relevant research remains limited. This study aimed to reveal the role and potential mechanism of miR-483 in PCOS. Material/Methods PCOS patients (n=20) were recruited for detecting miR-483 expression in lesion and normal ovary cortex. Human granulosa-like tumor cell line KGN was used to alter miR-483 expression by cell transfection. Cell viability and proliferation were analyzed by MTT assay and colony formation assay, and cell cycle was detected by flow cytometry. Interaction between miR-483 and IGF1 was verified by luciferase reporter assay. KGN cells were further treated by insulin to investigate the relationship between miR-483 and insulin. Results miR-483 was significantly down-regulated in lesion ovary cortex from PCOS patients (P<0.001). In KGN cells, overexpression of miR-483 inhibited cell viability and proliferation, and induced cell cycle arrest. miR-483 also inhibited CCNB1, CCND1, and CDK2. miR-483 sponge induced the opposite effects. miR-483 directly targeted IGF1 3′UTR, and IGF1 promoted KGN cell proliferation and reversed miR-483-inhibited cell viability. Insulin treatment in KGN cells inhibited miR-483, and promoted IGF1 and cell proliferation. Conclusions These results suggest that miR-483 is a PCOS suppressor inhibiting cell proliferation, possibly via targeting IGF1, and that it is involved in insulin-induced cell proliferation. miR-483 is a potential alternative for diagnosing and treating PCOS. PMID:27662007

  12. miR-483 is Down-Regulated in Polycystic Ovarian Syndrome and Inhibits KGN Cell Proliferation via Targeting Insulin-Like Growth Factor 1 (IGF1).

    PubMed

    Xiang, Yungai; Song, Yuxia; Li, Yan; Zhao, Dongmei; Ma, Liying; Tan, Li

    2016-09-23

    BACKGROUND Polycystic ovarian syndrome (PCOS) is a common metabolic disorder in premenopausal woman, characterized by hyperandrogenism, oligoanovulation, and insulin resistance. microRNAs play pivotal roles in regulating key factors of PCOS. However, relevant research remains limited. This study aimed to reveal the role and potential mechanism of miR-483 in PCOS. MATERIAL AND METHODS PCOS patients (n=20) were recruited for detecting miR-483 expression in lesion and normal ovary cortex. Human granulosa-like tumor cell line KGN was used to alter miR-483 expression by cell transfection. Cell viability and proliferation were analyzed by MTT assay and colony formation assay, and cell cycle was detected by flow cytometry. Interaction between miR-483 and IGF1 was verified by luciferase reporter assay. KGN cells were further treated by insulin to investigate the relationship between miR-483 and insulin. RESULTS miR-483 was significantly down-regulated in lesion ovary cortex from PCOS patients (P<0.001). In KGN cells, overexpression of miR-483 inhibited cell viability and proliferation, and induced cell cycle arrest. miR-483 also inhibited CCNB1, CCND1, and CDK2. miR-483 sponge induced the opposite effects. miR-483 directly targeted IGF1 3'UTR, and IGF1 promoted KGN cell proliferation and reversed miR-483-inhibited cell viability. Insulin treatment in KGN cells inhibited miR-483, and promoted IGF1 and cell proliferation. CONCLUSIONS These results suggest that miR-483 is a PCOS suppressor inhibiting cell proliferation, possibly via targeting IGF1, and that it is involved in insulin-induced cell proliferation. miR-483 is a potential alternative for diagnosing and treating PCOS.

  13. Association of Plasma Selenium Concentrations with Total IGF-1 Among Older Community-Dwelling Adults: the InCHIANTI Study

    PubMed Central

    Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Dall'Aglio, Elisabetta; Guralnik, Jack M.; Paolisso, Giuseppe; Semba, Richard D.; Nouvenne, Antonio; Borghi, Loris; Ceresini, Graziano; Ablondi, Fabrizio; Benatti, Mario; Ferrucci, Luigi

    2011-01-01

    Background and Aims Insulin-like growth factor (IGF-1) stimulates cell proliferation and inhibits cell apoptosis. Recent studies underline its importance as anabolic hormone and nutritional marker in older individuals. IGF-1 synthesis and bioactivity are modulated by nutritional factors including selenium intake. However, whether circulating IGF-1 levels are positively influenced by plasma selenium, one of the most important human antioxidants, is still unknown. Methods Selenium and total IGF-1 were measured in 951 men and women ≥65 years from the InCHIANTI study, Tuscany, Italy. Results Means (SD) of plasma selenium and total IGF-1 were 0.95 (0.15) µmol/L and 113.4 (31.2) ng/mL, respectively. After adjustment for age and sex, selenium levels were positively associated with total IGF-1 (ß ± SE: 43.76±11.2, p=0.0001).After further adjustment for total energy and alcohol intake, serum alanine amino transferase (ALT), congestive heart failure, selenium remained significantly associated with IGF-1 (β ± SE: 36.7 ± 12.2, p=0.003). The association was still significant when IL-6 was introduced in the model (β ± SE: 40.1 ± 12.0, p=0.0008). Conclusions We found an independent, positive and significant association between selenium and IGF-1 serum levels in community dwelling older adults. PMID:20416996

  14. Cyclic glycine-proline regulates IGF-1 homeostasis by altering the binding of IGFBP-3 to IGF-1

    NASA Astrophysics Data System (ADS)

    Guan, Jian; Gluckman, Peter; Yang, Panzao; Krissansen, Geoff; Sun, Xueying; Zhou, Yongzhi; Wen, Jingyuan; Phillips, Gemma; Shorten, Paul R.; McMahon, Chris D.; Wake, Graeme C.; Chan, Wendy H. K.; Thomas, Mark F.; Ren, April; Moon, Steve; Liu, Dong-Xu

    2014-03-01

    The homeostasis of insulin-like growth factor-1 (IGF-1) is essential for metabolism, development and survival. Insufficient IGF-1 is associated with poor recovery from wounds whereas excessive IGF-1 contributes to growth of tumours. We have shown that cyclic glycine-proline (cGP), a metabolite of IGF-1, can normalise IGF-1 function by showing its efficacy in improving the recovery from ischemic brain injury in rats and inhibiting the growth of lymphomic tumours in mice. Further investigation in cell culture suggested that cGP promoted the activity of IGF-1 when it was insufficient, but inhibited the activity of IGF-1 when it was excessive. Mathematical modelling revealed that the efficacy of cGP was a modulated IGF-1 effect via changing the binding of IGF-1 to its binding proteins, which dynamically regulates the balance between bioavailable and non-bioavailable IGF-1. Our data reveal a novel mechanism of auto-regulation of IGF-1, which has physiological and pathophysiological consequences and potential pharmacological utility.

  15. Clinical significance of proliferation, apoptosis and senescence of nasopharyngeal cells by the simultaneously blocking EGF, IGF-1 receptors and Bcl-xl genes

    SciTech Connect

    Dai, Guodong; Peng, Tao; Zhou, Xuhong; Zhu, Jun; Kong, Zhihua; Ma, Li; Xiong, Zhi; Yuan, Yulin

    2013-11-01

    Highlight: •Construction of shRNA segments expression vectors is valid by the investigation of RT-PCR for IGF1R, EGFR and Bcl-xl mRNA and protein expression. •Studies have suggested that the vectors in blocking these genes of the growth factor receptors and anti- apoptosis is capable of breaking the balance of tumor growth so that tumor trend apoptosis and senescence. •Simultaneously blocking multiple genes that are abnormally expressed may be more effective in treating cancer cells than silencing a single gene. -- Abstract: Background: In previous work, we constructed short hairpin RNA (shRNA) expression plasmids that targeted human EGF and IGF-1 receptors messenger RNA, respectively, and demonstrated that these vectors could induce apoptosis of human nasopharyngeal cell lines (CNE2) and inhibit ligand-induced pAkt and pErk activation. Method: We have constructed multiple shRNA expression vectors of targeting EGFR, IGF1R and Bcl-xl, which were transfected to the CNE2 cells. The mRNA expression was assessed by RT-PCR. The growth of the cells, cell cycle progression, apoptosis of the cells, senescent tumor cells and the proteins of EGFR, IGF1R and Bcl-xl were analyzed by MTT, flow cytometry, cytochemical therapy or Western blot. Results: In group of simultaneously blocking EGFR, IGF1R and Bcl-xl genes, the mRNA of EGFR, IGF1R and Bcl-xl expression was decreased by (66.66 ± 3.42)%, (73.97 ± 2.83)% and (64.79 ± 2.83)%, and the protein expressions was diminished to (67.69 ± 4.02)%, (74.32 ± 2.30)%, and (60.00 ± 3.34)%, respectively. Meanwhile, the cell apoptosis increased by 65.32 ± 0.18%, 65.16 ± 0.25% and 55.47 ± 0.45%, and senescent cells increased by 1.42 ± 0.15%, 2.26 ± 0.15% and 3.22 ± 0.15% in the second, third and fourth day cultures, respectively. Conclusions: Simultaneously blocking EGFR, IGF1R and Bcl-xl genes is capable of altering the balance between proliferating versus apoptotic and senescent cells in the favor of both of apoptosis and

  16. Low and Normal IGF-1 Levels in Patients with Chronic Medical Disorders (CMD) is Independent of Anterior Pituitary Hormone Deficiencies: Implications for Treating IGF-1 Abnormal Deficiencies with CMD.

    PubMed

    Braverman, E; Oscar-Berman, M; Lohmann, R; Kennedy, R; Kerner, M; Dushaj, K; Blum, K

    2013-02-09

    Over time, based on evidence-based medicine, a number of hormonal test levels including IGF-1 had been raised or lowered to meet new criteria standards. In particular, IGF-1 plasma levels have been shown in several studies to be an independent diagnostic tool in Adult Growth Hormone Deficiency (AGHD). Many endocrinology studies link low IGF-1 plasma levels with low levels of other anterior pituitary hormones (i.e., LH, FSH, and TSH). Low IGF-1 is considered by most to be between 84-100 µ/l and numerous studies recommend that raising IGF-1 to high normal range reverses Chronic Medical Diseases (CMD), improves bone mineral density (BMD), and fibromyalgia. Moreover, some studies suggest that low levels of IGF-1 by itself independent of anterior pituitary deficiencies is sufficient to determine AGHD in humans. In order to determine the relationship of low IGF-1 with that of LH, FSH, and TSH levels in subjects with CMD, we evaluated these levels (± SD) in 944 patients. Patients with IGF-1 below 84 µ/l, 100 µ/l, and 150 µ/l were accessed. 9.22% had less than 84 µ/l (SD ± 12.52); 19.9% had less than 100 µ/l (SD ± 9.54); and 51.6 had less than 150 µ/l (SD ± 26.0). Specifically, the percentages found for low LH, FSH, and TSH were only 4.2%, 4.8%, and 6.5%. We conclude that IGF-1 deficiencies occur independent of comorbid deficiencies of LH, FSH, and TSH. Finally, we propose that based on the present investigation, IGF-1 low levels between the range of 84-100 µ/l may be too low to be considered as an independent diagnostic marker to treat AGHD with CMD.

  17. Low and Normal IGF-1 Levels in Patients with Chronic Medical Disorders (CMD) is Independent of Anterior Pituitary Hormone Deficiencies: Implications for Treating IGF-1 Abnormal Deficiencies with CMD

    PubMed Central

    Braverman, E; Oscar-Berman, M; Lohmann, R; Kennedy, R; Kerner, M; Dushaj, K; Blum, K

    2013-01-01

    Over time, based on evidence–based medicine, a number of hormonal test levels including IGF-1 had been raised or lowered to meet new criteria standards. In particular, IGF-1 plasma levels have been shown in several studies to be an independent diagnostic tool in Adult Growth Hormone Deficiency (AGHD). Many endocrinology studies link low IGF-1 plasma levels with low levels of other anterior pituitary hormones (i.e., LH, FSH, and TSH). Low IGF-1 is considered by most to be between 84–100 µ/l and numerous studies recommend that raising IGF-1 to high normal range reverses Chronic Medical Diseases (CMD), improves bone mineral density (BMD), and fibromyalgia. Moreover, some studies suggest that low levels of IGF-1 by itself independent of anterior pituitary deficiencies is sufficient to determine AGHD in humans. In order to determine the relationship of low IGF-1 with that of LH, FSH, and TSH levels in subjects with CMD, we evaluated these levels (± SD) in 944 patients. Patients with IGF-1 below 84 µ/l, 100 µ/l, and 150 µ/l were accessed. 9.22% had less than 84 µ/l (SD ± 12.52); 19.9% had less than 100 µ/l (SD ± 9.54); and 51.6 had less than 150 µ/l (SD ± 26.0). Specifically, the percentages found for low LH, FSH, and TSH were only 4.2%, 4.8%, and 6.5%. We conclude that IGF-1 deficiencies occur independent of comorbid deficiencies of LH, FSH, and TSH. Finally, we propose that based on the present investigation, IGF-1 low levels between the range of 84–100 µ/l may be too low to be considered as an independent diagnostic marker to treat AGHD with CMD. PMID:23616929

  18. mIGF-1/JNK1/SirT1 signaling confers protection against oxidative stress in the heart.

    PubMed

    Vinciguerra, Manlio; Santini, Maria Paola; Martinez, Conception; Pazienza, Valerio; Claycomb, William C; Giuliani, Alessandro; Rosenthal, Nadia

    2012-02-01

    Oxidative stress contributes to the pathogenesis of aging-associated heart failure. Among various signaling pathways mediating oxidative stress, the NAD(+) -dependent protein deacetylase SirT1 has been implicated in the protection of heart muscle. Expression of a locally acting insulin-like growth factor-1 (IGF-1) propeptide (mIGF-1) helps the heart to recover from infarct and enhances SirT1 expression in cardiomyocytes (CM) in vitro, exerting protection from hypertrophic and oxidative stresses. To study the role of mIGF-1/SirT1 signaling in vivo, we generated cardiac-specific mIGF-1 transgenic mice in which SirT1 was depleted from adult CM in a tamoxifen-inducible and conditional fashion. Analysis of these mice confirmed that mIGF-1-induced SirT1 activity is necessary to protect the heart from paraquat (PQ)-induced oxidative stress and lethality. In cultured CM, mIGF-1 increases SirT1 expression through a c-Jun NH(2)-terminal protein kinase 1 (JNK1)-dependent signaling mechanism. Thus, mIGF-1 protects the heart from oxidative stress via SirT1/JNK1 activity, suggesting new avenues for cardiac therapy during aging and heart failure.

  19. Does the GH/IGF-1 axis contribute to skeletal sexual dimorphism? Evidence from mouse studies.

    PubMed

    Liu, Zhongbo; Mohan, Subburaman; Yakar, Shoshana

    2016-04-01

    The contribution of the gonadotropic axis to skeletal sexual dimorphism (SSD) was clarified in recent years. Studies with animal models of estrogen receptor (ER) or androgen receptor (AR) null mice, as well as mice with bone cell-specific ablation of ER or AR, revealed that both hormones play major roles in skeletal acquisition, and that estrogen regulates skeletal accrual in both sexes. The growth hormone (GH) and its downstream effector, the insulin-like growth factor-1 (IGF-1) are also major determinants of peak bone mass during puberty and young adulthood, and play important roles in maintaining bone integrity during aging. A few studies in both humans and animal models suggest that in addition to the differences in sex steroid actions on bone, sex-specific effects of GH and IGF-1 play essential roles in SSD. However, the contributions of the somatotropic (GH/IGF-1) axis to SSD are controversial and data is difficult to interpret. GH/IGF-1 are pleotropic hormones that act in an endocrine and autocrine/paracrine fashion on multiple tissues, affecting body composition as well as metabolism. Thus, understanding the contribution of the somatotropic axis to SSD requires the use of mouse models that will differentiate between these two modes of action. Elucidation of the relative contribution of GH/IGF-1 axis to SSD is significant because GH is approved for the treatment of normal children with short stature and children with congenital growth disorders. Thus, if the GH/IGF-1 axis determines SSD, treatment with GH may be tailored according to sex. In the following review, we give an overview of the roles of sex steroids in determining SSD and how they may interact with the GH/IGF-1 axis in bone. We summarize several mouse models with impaired somatotropic axis and speculate on the possible contribution of that axis to SSD.

  20. Small-Molecule Inhibition and Activation-Loop Trans-Phosphorylation of the IGF1 Receptor

    SciTech Connect

    Wu,J.; Li, W.; Craddock, B.; Foreman, K.; Mulvihill, M.; Ji, Q.; Miller, W.; Hubbard, S.

    2008-01-01

    The insulin-like growth factor-1 receptor (IGF1R) is a receptor tyrosine kinase (RTK) that has a critical role in mitogenic signalling during embryogenesis and an antiapoptotic role in the survival and progression of many human tumours. Here, we present the crystal structure of the tyrosine kinase domain of IGF1R (IGF1RK), in its unphosphorylated state, in complex with a novel compound, cis-3-[3-(4-methyl-piperazin-l-yl)-cyclobutyl]-1-(2-phenyl-quinolin-7-yl)-imidazo[1, 5-a]pyrazin-8-ylamine (PQIP), which we show is a potent inhibitor of both the unphosphorylated (basal) and phosphorylated (activated) states of the kinase. PQIP interacts with residues in the ATP-binding pocket and in the activation loop, which confers specificity for IGF1RK and the highly related insulin receptor (IR) kinase. In this crystal structure, the IGF1RK active site is occupied by Tyr1135 from the activation loop of an symmetry (two-fold)-related molecule. This dimeric arrangement affords, for the first time, a visualization of the initial trans-phosphorylation event in the activation loop of an RTK, and provides a molecular rationale for a naturally occurring mutation in the activation loop of the IR that causes type II diabetes mellitus.

  1. IR/IGF1R signaling as potential target for treatment of high-grade osteosarcoma

    PubMed Central

    2013-01-01

    Background High-grade osteosarcoma is an aggressive tumor most often developing in the long bones of adolescents, with a second peak in the 5th decade of life. Better knowledge on cellular signaling in this tumor may identify new possibilities for targeted treatment. Methods We performed gene set analysis on previously published genome-wide gene expression data of osteosarcoma cell lines (n=19) and pretreatment biopsies (n=84). We characterized overexpression of the insulin-like growth factor receptor (IGF1R) signaling pathways in human osteosarcoma as compared with osteoblasts and with the hypothesized progenitor cells of osteosarcoma – mesenchymal stem cells. This pathway plays a key role in the growth and development of bone. Since most profound differences in mRNA expression were found at and upstream of the receptor of this pathway, we set out to inhibit IR/IGF1R using OSI-906, a dual inhibitor for IR/IGF1R, on four osteosarcoma cell lines. Inhibitory effects of this drug were measured by Western blotting and cell proliferation assays. Results OSI-906 had a strong inhibitory effect on proliferation of 3 of 4 osteosarcoma cell lines, with IC50s below 100 nM at 72 hrs of treatment. Phosphorylation of IRS-1, a direct downstream target of IGF1R signaling, was inhibited in the responsive osteosarcoma cell lines. Conclusions This study provides an in vitro rationale for using IR/IGF1R inhibitors in preclinical studies of osteosarcoma. PMID:23688189

  2. Both IGF1R and INSR Knockdown Exert Antitumorigenic Effects in Prostate Cancer In Vitro and In Vivo

    PubMed Central

    Ofer, Philipp; Heidegger, Isabel; Eder, Iris E.; Schöpf, Bernd; Neuwirt, Hannes; Geley, Stephan; Massoner, Petra

    2015-01-01

    The IGF network with its main receptors IGF receptor 1 (IGF1R) and insulin receptor (INSR) is of major importance for cancer initiation and progression. To date, clinical studies targeting this network were disappointing and call for thorough analysis of the IGF network in cancer models. We highlight the oncogenic effects controlled by IGF1R and INSR in prostate cancer cells and show similarities as well as differences after receptor knockdown (KD). In PC3 prostate cancer cells stably transduced with inducible short hairpin RNAs, targeting IGF1R or INSR attenuated cell growth and proliferation ultimately driving cells into apoptosis. IGF1R KD triggered rapid and strong antiproliferative and proapoptotic responses, whereas these effects were less pronounced and delayed after INSR KD. Down-regulation of the antiapoptotic proteins myeloid cell leukemia-1 and survivin was observed in both KDs, whereas IGF1R KD also attenuated expression of prosurvival proteins B cell lymphoma-2 and B cell lymphoma-xL. Receptor KD induced cell death involved autophagy in particular upon IGF1R KD; however, no difference in mitochondrial energy metabolism was observed. In a mouse xenograft model, induction of IGF1R or INSR KD after tumor establishment eradicated most of the tumors. After 20 days of receptor KD, tumor cells were found only in 1/14 IGF1R and 3/14 INSR KD tumor remnants. Collectively, our data underline the oncogenic functions of IGF1R and INSR in prostate cancer namely growth, proliferation, and survival in vitro as well as in vivo and identify myeloid cell leukemia-1 and survivin as important mediators of inhibitory and apoptotic effects. PMID:26452103

  3. Both IGF1R and INSR Knockdown Exert Antitumorigenic Effects in Prostate Cancer In Vitro and In Vivo.

    PubMed

    Ofer, Philipp; Heidegger, Isabel; Eder, Iris E; Schöpf, Bernd; Neuwirt, Hannes; Geley, Stephan; Klocker, Helmut; Massoner, Petra

    2015-12-01

    The IGF network with its main receptors IGF receptor 1 (IGF1R) and insulin receptor (INSR) is of major importance for cancer initiation and progression. To date, clinical studies targeting this network were disappointing and call for thorough analysis of the IGF network in cancer models. We highlight the oncogenic effects controlled by IGF1R and INSR in prostate cancer cells and show similarities as well as differences after receptor knockdown (KD). In PC3 prostate cancer cells stably transduced with inducible short hairpin RNAs, targeting IGF1R or INSR attenuated cell growth and proliferation ultimately driving cells into apoptosis. IGF1R KD triggered rapid and strong antiproliferative and proapoptotic responses, whereas these effects were less pronounced and delayed after INSR KD. Down-regulation of the antiapoptotic proteins myeloid cell leukemia-1 and survivin was observed in both KDs, whereas IGF1R KD also attenuated expression of prosurvival proteins B cell lymphoma-2 and B cell lymphoma-xL. Receptor KD induced cell death involved autophagy in particular upon IGF1R KD; however, no difference in mitochondrial energy metabolism was observed. In a mouse xenograft model, induction of IGF1R or INSR KD after tumor establishment eradicated most of the tumors. After 20 days of receptor KD, tumor cells were found only in 1/14 IGF1R and 3/14 INSR KD tumor remnants. Collectively, our data underline the oncogenic functions of IGF1R and INSR in prostate cancer namely growth, proliferation, and survival in vitro as well as in vivo and identify myeloid cell leukemia-1 and survivin as important mediators of inhibitory and apoptotic effects.

  4. Insulin-like growth factor-1 (IGF-1) promotes myoblast proliferation and skeletal muscle growth of embryonic chickens via the PI3K/Akt signalling pathway.

    PubMed

    Yu, Minli; Wang, Huan; Xu, Yali; Yu, Debing; Li, Dongfeng; Liu, Xiuhong; Du, Wenxing

    2015-08-01

    During embryonic development, IGF-1 fulfils crucial roles in skeletal myogenesis. However, the involvement of IGF-1-induced myoblast proliferation in muscle growth is still unclear. In the present study, we have characterised the role of IGF-1 in myoblast proliferation both in vitro and in vivo and have revealed novel details of how exogenous IGF-1 influences myogenic genes in chicken embryos. The results show that IGF-1 significantly induces the proliferation of cultured myoblasts in a dose-dependent manner. Additionally, the IGF-1 treatment significantly promoted myoblasts entering a new cell cycle and increasing the mRNA expression levels of cell cycle-dependent genes. However, these effects were inhibited by the PI3K inhibitor LY294002 and the Akt inhibitor KP372-1. These data indicated that the pro-proliferative effect of IGF-1 was mediated in response to the PI3K/Akt signalling pathway. Moreover, we also showed that exogenous IGF-1 stimulated myoblast proliferation in vivo. IGF-1 administration obviously promoted the incorporation of BrdU and remarkably increased the number of PAX7-positive cells in the skeletal muscle of chicken embryos. Administration of IGF-1 also significantly induced the upregulation of myogenic factors gene, the enhancement of c-Myc and the inhibition of myostatin (Mstn) expression. These findings demonstrate that IGF-1 has strong activity as a promoter of myoblast expansion and muscle fiber formation during early myogenesis. Therefore, this study offers insight into the mechanisms responsible for IGF-1-mediated stimulation of embryonic skeletal muscle development, which could have important implications for the improvement of chicken meat production.

  5. Circulating IGF-1 and its role in cancer: lessons from the IGF-1 gene deletion (LID) mouse.

    PubMed

    Yakar, Shoshana; Pennisi, Patricia; Zhao, Hong; Zhang, Yang; LeRoith, Derek

    2004-01-01

    Recent epidemiological studies have suggested a statistical connection between serum IGF-1 levels in the upper quartile of the normal range and the relative risk of developing certain cancers. Our studies have focused on mouse models where circulating IGF-1 levels are reduced, while tissue expression of IGF-1 is normal. These mice show a lower risk for the development of colon and breast cancers and metastases when compared with control mice, and lend support to the hypothesis that circulating IGF-1 may be linked to cancer cell growth.

  6. Space radiation exposure persistently increased leptin and IGF1 in serum and activated leptin-IGF1 signaling axis in mouse intestine

    PubMed Central

    Suman, Shubhankar; Kumar, Santosh; Fornace, Albert J.; Datta, Kamal

    2016-01-01

    Travel into outer space is fraught with risk of exposure to energetic heavy ion radiation such as 56Fe ions, which due to its high linear energy transfer (high-LET) characteristics deposits higher energy per unit volume of tissue traversed and thus more damaging to cells relative to low-LET radiation such as γ rays. However, estimates of human health risk from energetic heavy ion exposure are hampered due to lack of tissue specific in vivo molecular data. We investigated long-term effects of 56Fe radiation on adipokines and insulin-like growth factor 1 (IGF1) signaling axis in mouse intestine and colon. Six- to eight-week-old C57BL/6J mice were exposed to 1.6 Gy of 56Fe ions. Serum and tissues were collected up to twelve months post-irradiation. Serum was analyzed for leptin, adiponectin, IGF1, and IGF binding protein 3. Receptor expressions and downstream signaling pathway alterations were studied in tissues. Irradiation increased leptin and IGF1 levels in serum, and IGF1R and leptin receptor expression in tissues. When considered along with upregulated Jak2/Stat3 pathways and cell proliferation, our data supports the notion that space radiation exposure is a risk to endocrine alterations with implications for chronic pathophysiologic changes in gastrointestinal tract. PMID:27558773

  7. Space radiation exposure persistently increased leptin and IGF1 in serum and activated leptin-IGF1 signaling axis in mouse intestine.

    PubMed

    Suman, Shubhankar; Kumar, Santosh; Fornace, Albert J; Datta, Kamal

    2016-08-25

    Travel into outer space is fraught with risk of exposure to energetic heavy ion radiation such as (56)Fe ions, which due to its high linear energy transfer (high-LET) characteristics deposits higher energy per unit volume of tissue traversed and thus more damaging to cells relative to low-LET radiation such as γ rays. However, estimates of human health risk from energetic heavy ion exposure are hampered due to lack of tissue specific in vivo molecular data. We investigated long-term effects of (56)Fe radiation on adipokines and insulin-like growth factor 1 (IGF1) signaling axis in mouse intestine and colon. Six- to eight-week-old C57BL/6J mice were exposed to 1.6 Gy of (56)Fe ions. Serum and tissues were collected up to twelve months post-irradiation. Serum was analyzed for leptin, adiponectin, IGF1, and IGF binding protein 3. Receptor expressions and downstream signaling pathway alterations were studied in tissues. Irradiation increased leptin and IGF1 levels in serum, and IGF1R and leptin receptor expression in tissues. When considered along with upregulated Jak2/Stat3 pathways and cell proliferation, our data supports the notion that space radiation exposure is a risk to endocrine alterations with implications for chronic pathophysiologic changes in gastrointestinal tract.

  8. Elevated levels of Insulin-like Growth Factor-1 (IGF-1) in drug-naïve patients with psychosis.

    PubMed

    Petrikis, Petros; Boumba, Vassiliki A; Tzallas, Alexandros T; Voulgari, Paraskevi V; Archimandriti, Dimitra T; Skapinakis, Petros; Mavreas, Venetsanos

    2016-12-30

    Insulin-like growth factor 1 (IGF-1) plays an important role in neurogenesis and synaptogenesis and may be implicated in schizophrenia, although data so far have been inconclusive. The aim of our study was to compare levels of IGF-1 in drug-naïve patients with a first episode of schizophrenia and related disorders with matched healthy controls. Forty drug naïve first-episode patients with schizophrenia and related disorders and forty healthy subjects matched for age, gender, body mass index (BMI) and smoking status were enrolled in the study. Serum levels of IGF-1 for each sample were measured in duplicate by the enzyme-linked immunosorbent assay (ELISA) method using human IGF-1. The median IGF-1 levels were significantly higher in drug-naive patients with psychosis compared to healthy controls (109.66ng/ml vs. 86.96ng/ml, respectively p=0.039). Multiple regression analysis revealed that differences in serum IGF-1 values were independent of glucose metabolism (fasting glucose, fasting insulin, insulin resistance) and cortisol. These results show that IGF-1 may be implicated in the pathophysiology of psychosis but confirmation is needed from other studies.

  9. Autophagy resolves early retinal inflammation in Igf1-deficient mice.

    PubMed

    Arroba, Ana I; Rodríguez-de la Rosa, Lourdes; Murillo-Cuesta, Silvia; Vaquero-Villanueva, Laura; Hurlé, Juan M; Varela-Nieto, Isabel; Valverde, Ángela M

    2016-09-01

    Insulin-like growth factor-1 (IGF-1) is a growth factor with differentiating, anti-apoptotic and metabolic functions in the periphery, and anti-inflammatory properties in the nervous system. Mice that have mutations in the Igf1 gene, rendering the gene product inactive (Igf1(-/-)), present with age-related visual loss accompanied by structural alterations in the first synapses of the retinal pathway. Recent advances have revealed a crucial role of autophagy in immunity and inflammation. Keeping in mind this close relationship, we aimed to decipher these processes in the context of the defects that occur during ageing in the retina of Igf1(-/-) mice. Tnfa and Il1b mRNAs, and phosphorylation of JNK and p38 MAPK were elevated in the retinas of 6- and 12-month old Igf1(-/-) mice compared to those in age-matched Igf1(+/+) controls. In 6-month-old Igf1(-/-) retinas, increased mRNA levels of the autophagy mediators Becn1, Atg9, Atg5 and Atg4, decreased p62 (also known as SQSTM1) protein expression together with an increased LC3-II:LC3-I ratio reflected active autophagic flux. However, in retinas from 12-month-old Igf1(-/-) mice, Nlrp3 mRNA, processing of the IL1β pro-form and immunostaining of active caspase-1 were elevated compared to those in age-matched Igf1(+/+) controls, suggesting activation of the inflammasome. This effect concurred with accumulation of autophagosomes and decreased autophagic flux in the retina. Microglia localization and status of activation in the retinas of 12-month-old Igf1(+/+) and Igf1(-/-) mice, analyzed by immunostaining of Cd11b and Iba-1, showed a specific distribution pattern in the outer plexiform layer (OPL), inner plexiform layer (IPL) and inner nuclear layer (INL), and revealed an increased number of activated microglia cells in the retina of 12-month-old blind Igf1(-/-) mice. Moreover, reactive gliosis was exclusively detected in the retinas from 12-month-old blind Igf1(-/-) mice. In conclusion, this study provides new evidence in

  10. Autophagy resolves early retinal inflammation in Igf1-deficient mice

    PubMed Central

    Rodríguez-de la Rosa, Lourdes; Murillo-Cuesta, Silvia; Vaquero-Villanueva, Laura; Hurlé, Juan M.; Varela-Nieto, Isabel; Valverde, Ángela M.

    2016-01-01

    ABSTRACT Insulin-like growth factor-1 (IGF-1) is a growth factor with differentiating, anti-apoptotic and metabolic functions in the periphery, and anti-inflammatory properties in the nervous system. Mice that have mutations in the Igf1 gene, rendering the gene product inactive (Igf1−/−), present with age-related visual loss accompanied by structural alterations in the first synapses of the retinal pathway. Recent advances have revealed a crucial role of autophagy in immunity and inflammation. Keeping in mind this close relationship, we aimed to decipher these processes in the context of the defects that occur during ageing in the retina of Igf1−/− mice. Tnfa and Il1b mRNAs, and phosphorylation of JNK and p38 MAPK were elevated in the retinas of 6- and 12-month old Igf1−/− mice compared to those in age-matched Igf1+/+ controls. In 6-month-old Igf1−/− retinas, increased mRNA levels of the autophagy mediators Becn1, Atg9, Atg5 and Atg4, decreased p62 (also known as SQSTM1) protein expression together with an increased LC3-II:LC3-I ratio reflected active autophagic flux. However, in retinas from 12-month-old Igf1−/− mice, Nlrp3 mRNA, processing of the IL1β pro-form and immunostaining of active caspase-1 were elevated compared to those in age-matched Igf1+/+ controls, suggesting activation of the inflammasome. This effect concurred with accumulation of autophagosomes and decreased autophagic flux in the retina. Microglia localization and status of activation in the retinas of 12-month-old Igf1+/+ and Igf1−/− mice, analyzed by immunostaining of Cd11b and Iba-1, showed a specific distribution pattern in the outer plexiform layer (OPL), inner plexiform layer (IPL) and inner nuclear layer (INL), and revealed an increased number of activated microglia cells in the retina of 12-month-old blind Igf1−/− mice. Moreover, reactive gliosis was exclusively detected in the retinas from 12-month-old blind Igf1−/− mice. In conclusion, this study

  11. Insulin receptor functionally enhances multistage tumor progression and conveys intrinsic resistance to IGF-1R targeted therapy

    PubMed Central

    Ulanet, Danielle B.; Ludwig, Dale L.; Kahn, C. Ronald; Hanahan, Douglas

    2010-01-01

    The type 1 insulin-like growth factor receptor (IGF-1R) tyrosine kinase is an important mediator of the protumorigenic effects of IGF-I/II, and inhibitors of IGF-1R signaling are currently being tested in clinical cancer trials aiming to assess the utility of this receptor as a therapeutic target. Despite mounting evidence that the highly homologous insulin receptor (IR) can also convey protumorigenic signals, its direct role in cancer progression has not been genetically defined in vivo, and it remains unclear whether such a role for IR signaling could compromise the efficacy of selective IGF-1R targeting strategies. A transgenic mouse model of pancreatic neuroendocrine carcinogenesis engages the IGF signaling pathway, as revealed by its dependence on IGF-II and by accelerated malignant progression upon IGF-1R overexpression. Surprisingly, preclinical trials with an inhibitory monoclonal antibody to IGF-1R did not significantly impact tumor growth, prompting us to investigate the involvement of IR. The levels of IR were found to be significantly up-regulated during multistep progression from hyperplastic lesions to islet tumors. Its functional involvement was revealed by genetic disruption of the IR gene in the oncogene-expressing pancreatic β cells, which resulted in reduced tumor burden accompanied by increased apoptosis. Notably, the IR knockout tumors now exhibited sensitivity to anti–IGF-1R therapy; similarly, high IR to IGF-1R ratios demonstrably conveyed resistance to IGF-1R inhibition in human breast cancer cells. The results predict that elevated IR signaling before and after treatment will respectively manifest intrinsic and adaptive resistance to anti–IGF-1R therapies. PMID:20457905

  12. Apoptosis induced by an anti-epidermal growth factor receptor monoclonal antibody in a human colorectal carcinoma cell line and its delay by insulin.

    PubMed Central

    Wu, X; Fan, Z; Masui, H; Rosen, N; Mendelsohn, J

    1995-01-01

    Both EGF and insulin, or IGF, stimulate the growth of many cell types by activating receptors that contain tyrosine kinase activities. A monoclonal antibody (mAb 225) against the EGF receptor produced in this laboratory has been shown to competitively inhibit EGF binding and block activation of receptor tyrosine kinase. Here we report that a human colorectal carcinoma cell line, DiFi, which expresses high levels of EGF receptors on plasma membranes, can be induced to undergo G1 cell cycle arrest and programmed cell death (apoptosis) when cultured with mAb 225 at concentrations that saturate EGF receptors. Addition of IGF-1 or high concentrations of insulin can delay apoptosis induced by mAb 225, while the G1 arrest cannot be reversed by either IGF-1 or insulin. Insulin/IGF-1 cannot activate EGF receptor tyrosine kinase that has been inhibited by mAb 225. Moreover, an mAb against the IGF-1 receptor, which has little direct effect on DiFi cell growth, can block the capacity of insulin/IGF-1 to delay apoptosis induced by mAb 225, suggesting that the insulin/IGF-1-mediated delay of apoptosis is acting through the IGF-1 receptor. In contrast, insulin/IGF-1 cannot delay the apoptosis caused by the DNA damaging agent, cisplatin. The results indicate that EGF receptor activation is required both for cell cycle progression and for prevention of apoptosis in DiFi cells, and that a signal transduction pathway shared by receptors for insulin/IGF-1 and EGF may be involved in regulating apoptosis triggered by blockade of the EGF receptor. Images PMID:7706497

  13. Estrogen-mediated regulation of Igf1 transcription and uterine growth involves direct binding of estrogen receptor alpha to estrogen-responsive elements.

    PubMed

    Hewitt, Sylvia C; Li, Yin; Li, Leping; Korach, Kenneth S

    2010-01-22

    Estrogen enables uterine proliferation, which depends on synthesis of the IGF1 growth factor. This proliferation and IGF1 synthesis requires the estrogen receptor (ER), which binds directly to target DNA sequences (estrogen-responsive elements or EREs), or interacts with other transcription factors, such as AP1, to impact transcription. We observe neither uterine growth nor an increase in Igf1 transcript in a mouse with a DNA-binding mutated ER alpha (KIKO), indicating that both Igf1 regulation and uterine proliferation require the DNA binding function of the ER. We identified several potential EREs in the Igf1 gene, and chromatin immunoprecipitation analysis revealed ER alpha binding to these EREs in wild type but not KIKO chromatin. STAT5 is also reported to regulate Igf1; uterine Stat5a transcript is increased by estradiol (E(2)), but not in KIKO or alpha ERKO uteri, indicating ER alpha- and ERE-dependent regulation. ER alpha binds to a potential Stat5a ERE. We hypothesize that E(2) increases Stat5a transcript through ERE binding; that ER alpha, either alone or together with STAT5, then acts to increase Igf1 transcription; and that the resulting lack of IGF1 impairs KIKO uterine growth. Treatment with exogenous IGF1, alone or in combination with E(2), induces proliferation in wild type but not KIKO uteri, indicating that IGF1 replacement does not rescue the KIKO proliferative response. Together, these observations suggest in contrast to previous in vitro studies of IGF-1 regulation involving AP1 motifs that direct ER alpha-DNA interaction is required to increase Igf1 transcription. Additionally, full ER alpha function is needed to mediate other cellular signals of the growth factor for uterine growth.

  14. The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

    SciTech Connect

    Zuloaga, R.; Fuentes, E.N.; Molina, A.; Valdés, J.A.

    2013-10-18

    Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP{sub 3}/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.

  15. Mechanical Stimulation and IGF-1 Enhance mRNA Translation Rate in Osteoblasts Via Activation of the AKT-mTOR Pathway.

    PubMed

    Bakker, Astrid D; Gakes, Tom; Hogervorst, Jolanda M A; de Wit, Gerard M J; Klein-Nulend, Jenneke; Jaspers, Richard T

    2016-06-01

    Insulin-like growth factor-1 (IGF-1) is anabolic for muscle by enhancing the rate of mRNA translation via activation of AKT and subsequent activation of the mammalian target of rapamycin complex 1 (mTOR), thereby increasing cellular protein production. IGF-1 is also anabolic for bone, but whether the mTOR pathway plays a role in the rate of bone matrix protein production by osteoblasts is unknown. We hypothesized that anabolic stimuli such as mechanical loading and IGF-1 stimulate protein synthesis in osteoblasts via activation of the AKT-mTOR pathway. MC3T3-E1 osteoblasts were either or not subjected for 1 h to mechanical loading by pulsating fluid flow (PFF) or treated with or without human recombinant IGF-1 (1-100 ng/ml) for 0.5-6 h, to determine phosphorylation of AKT and p70S6K (downstream of mTOR) by Western blot. After 4 days of culture with or without the mTOR inhibitor rapamycin, total protein, DNA, and gene expression were quantified. IGF-1 (100 ng/ml) reduced IGF-1 gene expression, although PFF enhanced IGF-1 expression. IGF-1 did not affect collagen-I gene expression. IGF-1 dose-dependently enhanced AKT and p70S6K phosphorylation at 2 and 6 h. PFF enhanced phosphorylation of AKT and p70S6K already within 1 h. Both IGF-1 and PFF enhanced total protein per cell by ∼30%, but not in the presence of rapamycin. Our results show that IGF-1 and PFF activate mTOR, thereby stimulating the rate of mRNA translation in osteoblasts. The known anabolic effect of mechanical loading and IGF-1 on bone may thus be partly explained by mTOR-mediated enhanced protein synthesis in osteoblasts.

  16. Effects of IGF-1 on In Vitro Culture of Bovine Preantral Follicles are Dose-Dependent.

    PubMed

    Jimenez, C R; de Azevedo, J L; Silveira, R G; Penitente-Filho, J; Carrascal-Triana, E L; Zolini, A M; Araujo, V R; Torres, Caa; Gonçalves, W G

    2016-06-01

    This study aimed at assessing the effect of different concentrations of the growth factor similar to insulin 1 (IGF-1) in the development, survival and ultrastructure of the bovine preantral follicles cultured in situ. Fragments of bovine ovarian cortical tissue were cultured during 1 and 7 days in 1 ml of α-MEM(+) , supplemented with different concentrations of human recombinant IGF-1 (0, 30, 70 and 100 ng/ml), in an incubator at 37°C and 5% of CO2 in 24-well plates with total replacement of the medium every 2 days. Non-cultured ovarian fragments (control) and ovarian fragments cultured during 1 and 7 days were processed for classic histology, mechanical isolation and electron transmission microscopy (ETM). Parameters such as normality, viability, activation, development, diameter and ultrastructure were evaluated. All statistical analyses were carried out using sas Version 9.2. The results showed that the percentage of follicles morphologically normal in the IGF-1 30 ng/ml treatment was similar to the fresh control (p > 0.05) both on the day 1 and on the day 7 of in vitro culture. In the viability analysis, the cultured treatments maintained the percentage of viable follicles during the entire culture period (p > 0.05). After 7 days of culture, the IGF-1 30 ng/ml treatment showed higher percentages of developing follicles (48.33%) than those of the fresh control (22.22%) and the cultured treatments (p < 0.05). Also, after 7 days of culture, IGF-1 30 ng/ml presented a higher follicular diameter when compared to the control and other concentrations of IGF-1 tested. Ultrastructurally, the non-cultured control and IGF-1 30 ng/ml, after 7 days of culture, showed conserved oocytes, nuclei and organelles. Hence, it is concluded that IGF-1 30 ng/ml was the most efficient concentration for the development of bovine preantral follicles cultured in vitro.

  17. Growth hormone (GH)-transgenic insulin-like growth factor 1 (IGF1)-deficient mice allow dissociation of excess GH and IGF1 effects on glomerular and tubular growth.

    PubMed

    Blutke, Andreas; Schneider, Marlon R; Wolf, Eckhard; Wanke, Rüdiger

    2016-03-01

    Growth hormone (GH)-transgenic mice with permanently elevated systemic levels of GH and insulin-like growth factor 1 (IGF1) reproducibly develop renal and glomerular hypertrophy and subsequent progressive glomerulosclerosis, finally leading to terminal renal failure. To dissociate IGF1-dependent and -independent effects of GH excess on renal growth and lesion development in vivo, the kidneys of 75 days old IGF1-deficient (I(-/-)) and of IGF1-deficient GH-transgenic mice (I(-/-)/G), as well as of GH-transgenic (G) and nontransgenic wild-type control mice (I(+/+)) were examined by quantitative stereological and functional analyses. Both G and I(-/-)/G mice developed glomerular hypertrophy, hyperplasia of glomerular mesangial and endothelial cells, podocyte hypertrophy and foot process effacement, albuminuria, and glomerulosclerosis. However, I(-/-)/G mice exhibited less severe glomerular alterations, as compared to G mice. Compared to I(+/+) mice, G mice exhibited renal hypertrophy with a significant increase in the number without a change in the size of proximal tubular epithelial (PTE) cells. In contrast, I(-/-)/G mice did not display significant PTE cell hyperplasia, as compared to I(-/-) mice. These findings indicate that GH excess stimulates glomerular growth and induces lesions progressing to glomerulosclerosis in the absence of IGF1. In contrast, IGF1 represents an important mediator of GH-dependent proximal tubular growth in GH-transgenic mice.

  18. Involvement of Igf1r in Bronchiolar Epithelial Regeneration: Role during Repair Kinetics after Selective Club Cell Ablation

    PubMed Central

    López, Icíar P.; Piñeiro-Hermida, Sergio; Pais, Rosete S.; Torrens, Raquel; Hoeflich, Andreas; Pichel, José G.

    2016-01-01

    Regeneration of lung epithelium is vital for maintaining airway function and integrity. An imbalance between epithelial damage and repair is at the basis of numerous chronic lung diseases such as asthma, COPD, pulmonary fibrosis and lung cancer. IGF (Insulin-like Growth Factors) signaling has been associated with most of these respiratory pathologies, although their mechanisms of action in this tissue remain poorly understood. Expression profiles analyses of IGF system genes performed in mouse lung support their functional implication in pulmonary ontogeny. Immuno-localization revealed high expression levels of Igf1r (Insulin-like Growth Factor 1 Receptor) in lung epithelial cells, alveolar macrophages and smooth muscle. To further understand the role of Igf1r in pulmonary homeostasis, two distinct lung epithelial-specific Igf1r mutant mice were generated and studied. The lack of Igf1r disturbed airway epithelial differentiation in adult mice, and revealed enhanced proliferation and altered morphology in distal airway club cells. During recovery after naphthalene-induced club cell injury, the kinetics of terminal bronchiolar epithelium regeneration was hindered in Igf1r mutants, revealing increased proliferation and delayed differentiation of club and ciliated cells. Amid airway restoration, lungs of Igf1r deficient mice showed increased levels of Igf1, Insr, Igfbp3 and epithelial precursor markers, reduced amounts of Scgb1a1 protein, and alterations in IGF signaling mediators. These results support the role of Igf1r in controlling the kinetics of cell proliferation and differentiation during pulmonary airway epithelial regeneration after injury. PMID:27861515

  19. Oncogenic functions of IGF1R and INSR in prostate cancer include enhanced tumor growth, cell migration and angiogenesis.

    PubMed

    Heidegger, Isabel; Kern, Johann; Ofer, Philipp; Klocker, Helmut; Massoner, Petra

    2014-05-15

    We scrutinized the effect of insulin receptor (INSR) in addition to IGF1R in PCa using in vitro and in vivo models. In-vitro overexpression of IGF1R and INSRA, but not INSRB increased cell proliferation, colony formation, migration, invasion and resistance to apoptosis in prostate cancer cells (DU145, LNCaP, PC3). Opposite effects were induced by downregulation of IGF1R and total INSR, but not INSRB. In contrast to tumor cells, non-cancerous epithelial cells of the prostate (EP156T, RWPE-1) were inhibited on overexpression and stimulated by knockdown of receptors. In-vivo analyses using the chicken allantoic membrane assay confirmed the tumorigenic effects of IGF1R and INSR. Apart of promoting tumor growth, IGF1R and INSR overexpression also enhanced angiogenesis indicated by higher vessel density and increased number of desmin-immunoreactive pericytes. Our study underscores the oncogenic impact of IGF1R including significant effects on tumor growth, cell migration, sensitivity to apoptotic/chemotherapeutic agents and angiogenesis, and characterizes the INSR, in particular the isoform INSRA, as additional cancer-promoting receptor in prostate cancer. Both, the insulin-like growth factor receptor 1 and the insulin receptor exert oncogenic functions, thus proposing that both receptors need to be considered in therapeutic settings.

  20. IGF-1 (Insulin-Like Growth Factor -1) Test

    MedlinePlus

    ... diagnose pituitary gland dysfunction and decreased pituitary hormones ( hypopituitarism ). IGF-1 testing and a GH suppression test ... to a more general decrease in pituitary function ( hypopituitarism ), then several other endocrine glands and their pituitary ...

  1. Insulinlike growth factor (IGF)-1 administration ameliorates disease manifestations in a mouse model of spinal and bulbar muscular atrophy.

    PubMed

    Rinaldi, Carlo; Bott, Laura C; Chen, Ke-lian; Harmison, George G; Katsuno, Masahisa; Sobue, Gen; Pennuto, Maria; Fischbeck, Kenneth H

    2012-12-06

    Spinal and bulbar muscular atrophy is an X-linked motor neuron disease caused by polyglutamine expansion in the androgen receptor. Patients develop slowly progressive proximal muscle weakness, muscle atrophy and fasciculations. Affected individuals often show gynecomastia, testicular atrophy and reduced fertility as a result of mild androgen insensitivity. No effective disease-modifying therapy is currently available for this disease. Our recent studies have demonstrated that insulinlike growth factor (IGF)-1 reduces the mutant androgen receptor toxicity through activation of Akt in vitro, and spinal and bulbar muscular atrophy transgenic mice that also overexpress a noncirculating muscle isoform of IGF-1 have a less severe phenotype. Here we sought to establish the efficacy of daily intraperitoneal injections of mecasermin rinfabate, recombinant human IGF-1 and IGF-1 binding protein 3, in a transgenic mouse model expressing the mutant androgen receptor with an expanded 97 glutamine tract. The study was done in a controlled, randomized, blinded fashion, and, to reflect the clinical settings, the injections were started after the onset of disease manifestations. The treatment resulted in increased Akt phosphorylation and reduced mutant androgen receptor aggregation in muscle. In comparison to vehicle-treated controls, IGF-1-treated transgenic mice showed improved motor performance, attenuated weight loss and increased survival. Our results suggest that peripheral tissue can be targeted to improve the spinal and bulbar muscular atrophy phenotype and indicate that IGF-1 warrants further investigation in clinical trials as a potential treatment for this disease.

  2. Stable interference of EWS–FLI1 in an Ewing sarcoma cell line impairs IGF-1/IGF-1R signalling and reveals TOPK as a new target

    PubMed Central

    Herrero-Martín, D; Osuna, D; Ordóñez, J L; Sevillano, V; Martins, A S; Mackintosh, C; Campos, M; Madoz-Gúrpide, J; Otero-Motta, A P; Caballero, G; Amaral, A T; Wai, D H; Braun, Y; Eisenacher, M; Schaefer, K-L; Poremba, C; de Alava, E

    2009-01-01

    BACKGROUND: Ewing sarcoma is a paradigm of solid tumour -bearing chromosomal translocations resulting in fusion proteins that act as deregulated transcription factors. Ewing sarcoma translocations fuse the EWS gene with an ETS transcription factor, mainly FLI1. Most of the EWS–FLI1 target genes still remain unknown and many have been identified in heterologous model systems. METHODS: We have developed a stable RNA interference model knocking down EWS–FLI1 in the Ewing sarcoma cell line TC71. Gene expression analyses were performed to study the effect of RNA interference on the genetic signature of EWS–FLI1 and to identify genes that could contribute to tumourigenesis. RESULTS: EWS–FLI1 inhibition induced apoptosis, reduced cell migratory and tumourigenic capacities, and caused reduction in tumour growth. IGF-1 was downregulated and the IGF-1/IGF-1R signalling pathway was impaired. PBK/TOPK (T-LAK cell-originated protein kinase) expression was decreased because of EWS–FLI1 inhibition. We showed that TOPK is a new target gene of EWS–FLI1. TOPK inhibition prompted a decrease in the proliferation rate and a dramatic change in the cell's ability to grow in coalescence. CONCLUSION: This is the first report of TOPK activity in Ewing sarcoma and suggests a significant role of this MAPKK-like protein kinase in the Ewing sarcoma biology. PMID:19491900

  3. Exercise training effects on skeletal muscle plasticity and IGF-1 receptors in frail elders.

    PubMed

    Urso, Maria L; Fiatarone Singh, Maria A; Ding, Wenjing; Evans, William J; Cosmas, Arthur C; Manfredi, Thomas G

    2005-06-01

    Age-related sarcopenia inhibits mobility, increasing the risk for developing many diseases, including diabetes, arthritis, osteoporosis, and heart disease. Tissue plasticity, or the ability to regenerate following stress, has been a subject of question in aging humans. We assessed the impact of 10-weeks of resistance training on markers of skeletal muscle plasticity and insulin growth factor-1 (IGF-1) receptor density in a sub sample of subjects who, in an earlier study, demonstrated enhanced immunohistochemical labeling of IGF following resistance training. Muscle biopsies from the vastus lateralis of five elderly men and women were taken prior to and following 10 weeks of resistance training (N = 3) or a control period (N = 2). Immunogold labeling and quantitative electron microscopy techniques were used to analyze markers of IGF-1 receptor density and tissue plasticity. The experimental subjects showed a 161 ± 93.7% increase in Z band damage following resistance training. Myofibrillar central nuclei increased 296 ± 120% (P = 0. 029) in the experimental subjects. Changes in the percent of damaged Z bands were associated with alterations in the presence of central nuclei (r = 0.668; P = 0.0347). Post hoc analysis revealed that the relative pre/post percent changes in myofibrillar Z band damage and central nuclei were not statistically different between the control and exercise groups. Exercise training increased myofibrillar IGF-1 receptor densities in the exercise subjects (P = 0.008), with a non-significant increase in the control group. Labeling patterns suggested enhanced receptor density around the Z bands, sarcolemma, and mitochondrial and nuclear membranes. Findings from this study suggest that the age-related downregulation of the skeletal muscle IGF-1 system may be reversed to some extent with progressive resistance training. Furthermore, skeletal muscle tissue plasticity in the frail elderly is maintained at least to some extent as exemplified by the

  4. Estrogens and Insulin-Like Growth Factor 1 Modulate Neoplastic Cell Growth in Human Cholangiocarcinoma

    PubMed Central

    Alvaro, Domenico; Barbaro, Barbara; Franchitto, Antonio; Onori, Paolo; Glaser, Shannon S.; Alpini, Gianfranco; Francis, Heather; Marucci, Luca; Sterpetti, Paola; Ginanni-Corradini, Stefano; Onetti Muda, Andrea; Dostal, David E.; De Santis, Adriano; Attili, Adolfo F.; Benedetti, Antonio; Gaudio, Eugenio

    2006-01-01

    We investigated the expression of estrogen receptors (ERs), insulin-like growth factor 1 (IGF-1), and IGF-1R (receptor) in human cholangiocarcinoma and cholangiocarcinoma cell lines (HuH-28, TFK-1, Mz-ChA-1), evaluating the role of estrogens and IGF-1 in the modulation of neoplastic cell growth. ER-α, ER-β, IGF-1, and IGF-1R were expressed (immunohistochemistry) in all biopsies (18 of 18) of intrahepatic cholangiocarcinoma. ER-α was expressed (Western blot) only by the HuH-28 cell line (intrahepatic cholangiocarcinoma), whereas ER-β, IGF-1, and IGF-1R were expressed in the three cell lines examined. In serum-deprived HuH-28 cells, serum readmission induced stimulation of cell proliferation that was inhibited by ER and IGF-1R antagonists. 17β-Estradiol and IGF-1 stimulated proliferation of HuH-28 cells to a similar extent to that of MCF7 (breast cancer) but greater than that of TFK-1 and Mz-ChA-1, inhibiting apoptosis and exerting additive effects. These effects of 17β-estradiol and IGF-1 were associated with enhanced protein expression of ER-α, phosphorylated (p)-ERK1/2 and pAKT but with decreased expression of ER-β. Finally, transfection of IGF-1R anti-sense oligonucleotides in HuH-28 cells markedly decreased cell proliferation. In conclusion, human intrahepatic cholangiocarcinomas express receptors for estrogens and IGF-1, which cooperate in the modulation of cell growth and apoptosis. Modulation of ER and IGF-1R could represent a strategy for the management of cholangiocarcinoma. PMID:16936263

  5. Intermittent Compressive Stress Enhanced Insulin-Like Growth Factor-1 Expression in Human Periodontal Ligament Cells

    PubMed Central

    Pumklin, Jittima; Manokawinchoke, Jeeranan; Bhalang, Kanokporn; Pavasant, Prasit

    2015-01-01

    Mechanical force was shown to promote IGF-1 expression in periodontal ligament both in vitro and in vivo. Though the mechanism of this effect has not yet been proved, here we investigated the molecular mechanism of intermittent mechanical stress on IGF-1 expression. In addition, the role of hypoxia on the intermittent compressive stress on IGF-1 expression was also examined. In this study, human periodontal ligament cells (HPDLs) were stimulated with intermittent mechanical stress for 24 hours. IGF-1 expression was examined by real-time polymerase chain reaction. Chemical inhibitors were used to determine molecular mechanisms of these effects. For hypoxic mimic condition, the CoCl2 supplementation was employed. The results showed that intermittent mechanical stress dramatically increased IGF-1 expression at 24 h. The pretreatment with TGF-β receptor I or TGF-β1 antibody could inhibit the intermittent mechanical stress-induced IGF-1 expression. Moreover, the upregulation of TGF-β1 proteins was detected in intermittent mechanical stress treated group. Correspondingly, the IGF-1 expression was upregulated upon being treated with recombinant human TGF-β1. Further, the hypoxic mimic condition attenuated the intermittent mechanical stress and rhTGF-β1-induced IGF-1 expression. In summary, this study suggests intermittent mechanical stress-induced IGF-1 expression in HPDLs through TGF-β1 and this phenomenon could be inhibited in hypoxic mimic condition. PMID:26106417

  6. Role and Importance of IGF-1 in Traumatic Brain Injuries

    PubMed Central

    Mangiola, Annunziato; Vigo, Vera; Anile, Carmelo; De Bonis, Pasquale; Marziali, Giammaria; Lofrese, Giorgio

    2015-01-01

    It is increasingly affirmed that most of the long-term consequences of TBI are due to molecular and cellular changes occurring during the acute phase of the injury and which may, afterwards, persist or progress. Understanding how to prevent secondary damage and improve outcome in trauma patients, has been always a target of scientific interest. Plans of studies focused their attention on the posttraumatic neuroendocrine dysfunction in order to achieve a correlation between hormone blood level and TBI outcomes. The somatotropic axis (GH and IGF-1) seems to be the most affected, with different alterations between the acute and late phases. IGF-1 plays an important role in brain growth and development, and it is related to repair responses to damage for both the central and peripheral nervous system. The IGF-1 blood levels result prone to decrease during both the early and late phases after TBI. Despite this, experimental studies on animals have shown that the CNS responds to the injury upregulating the expression of IGF-1; thus it appears to be related to the secondary mechanisms of response to posttraumatic damage. We review the mechanisms involving IGF-1 in TBI, analyzing how its expression and metabolism may affect prognosis and outcome in head trauma patients. PMID:26417600

  7. PI3 kinase/Akt activation mediates estrogen and IGF-1 nigral DA neuronal neuroprotection against a unilateral rat model of Parkinson's disease.

    PubMed

    Quesada, Arnulfo; Lee, Becky Y; Micevych, Paul E

    2008-04-01

    Recently, using the medial forebrain bundle (MFB) 6-hydroxydopmaine (6-OHDA) lesion rat model of Parkinson's disease (PD), we have demonstrated that blockade of central IGF-1 receptors (IGF-1R) attenuated estrogen neuroprotection of substantia nigra pars compacta (SNpc) DA neurons, but exacerbated 6-OHDA lesions in IGF-1 only treated rats (Quesada and Micevych [2004]: J Neurosci Res 75:107-116). This suggested that the IGF-1 system is a central mechanism through which estrogen acts to protect the nigrostriatal DA system. Moreover, these results also suggest that IGF-1R-induced intracellular signaling pathways are involved in the estrogen mechanism that promotes neuronal survival. In vitro, two convergent intracellular signaling pathways used by estrogen and IGF-1, the mitogen-activated protein kinase (MAPK/ERK), and phosphatidyl-inositol-3-kinase/Akt (PI3K/Akt), have been demonstrated to be neuroprotective. Continuous central infusions of MAPK/ERK and PI3K/Akt inhibitors were used to test the hypothesis that one or both of these signal transduction pathways mediates estrogen and/or IGF-1 neuroprotection of SNpc DA neurons after a unilateral administration of 6-OHDA into the MFB of rats. Motor behavior tests and tyrosine hydroxylase immunoreactivity revealed that the inhibitor of the PI3K/Akt pathway (LY294002) blocked the survival effects of both estrogen and IGF-1, while an inhibitor of the MAPK/ERK signaling (PD98059) was ineffective. Western blot analyses showed that estrogen and IGF-1 treatments increased PI3K/Akt activation in the SN; however, MAPK/ERK activation was decreased in the SN. Indeed, continuous infusions of inhibitors blocked phosphorylation of PI3K/Akt and MAPK/ERK. These findings indicate that estrogen and IGF-1-mediated SNpc DA neuronal protection is dependent on PI3K/Akt signaling, but not on the MAPK/ERK pathway.

  8. Icaritin, a novel FASN inhibitor, exerts anti-melanoma activities through IGF-1R/STAT3 signaling

    PubMed Central

    Wu, Jinfeng; Du, Juan; Fu, Xiuqiong; Liu, Bin; Cao, Huihui; Li, Ting; Su, Tao; Xu, Jinhua; Tse, Anfernee Kai-Wing; Yu, Zhi-Ling

    2016-01-01

    Icaritin (IT) is a flavonoid isolated from Herba Epimedii. In this study, we evaluated the anti-melanoma activities of IT, and determined its cytotoxic mechanism. We found that IT exerted cytotoxicity to melanoma cells. Furthermore, IT induced melanoma cell apoptosis, which was accompanied with PARP cleavage. Mechanistically, IT suppressed p-STAT3 (tyr705) level in parallel with increases of p-STAT3 (ser727), p-ERK and p-AKT. IT significantly inhibited STAT3 nuclear translocation and reduced the levels of STAT3 -targeted genes. IT also inhibited IGF-1-induced STAT3 activation through down-regulation of total IGF-1R level. No dramatic changes in IGF-1R mRNA levels were observed in IT-treated cells, suggesting that IT acted primarily at a post-transcriptional level. Using molecular docking analysis, IT was identified as a novel fatty acid synthase (FASN) inhibitor. We found that IT reduced the level of total IGF-1R via FASN inhibition. In summary, we reported that IT exerted anti-melanoma activities, and these effects were partially due to inhibition of FASN/IGF-1R/STAT3 signaling. PMID:27323414

  9. Insulin activates EGFR by stimulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells.

    PubMed

    Shin, Miyoung; Yang, Eun Gyeong; Song, Hyun Kyu; Jeon, Hyesung

    2015-06-01

    The expression of epidermal growth factor receptor (EGFR) is an important diagnostic marker for triple-negative breast cancer (TNBC) cells, which lack three hormonal receptors: estrogen and progesterone receptors as well as epidermal growth factor receptor 2. EGFR transactivation can cause drug resistance in many cancers including TNBC, but the mechanism underlying this phenomenon is poorly defined. Here, we demonstrate that insulin treatment induces EGFR activation by stimulating the interaction of EGFR with insulin-like growth factor receptor 1 (IGF-1R) in the MDA-MB-436 TNBC cell line. These cells express low levels of EGFR, while exhibiting high levels of IGF-1R expression and phosphorylation. Low-EGFRexpressing MDA-MB-436 cells show high sensitivity to insulinstimulated cell growth. Therefore, unexpectedly, insulin stimulation induced EGFR transactivation by regulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells.

  10. Conjugated linoleic acids attenuate FSH- and IGF1-stimulated cell proliferation; IGF1, GATA4, and aromatase expression; and estradiol-17β production in buffalo granulosa cells involving PPARγ, PTEN, and PI3K/Akt.

    PubMed

    Sharma, Isha; Singh, Dheer

    2012-09-01

    Conjugated linoleic acid (CLA) has drawn much interest in last two decades in the area ranging from anticancer activity to obesity. A number of research papers have been published recently with regard to CLA's additional biological functions as reproductive benefits. However, not much is known how this mixture of isomeric compounds mediates its beneficial effects particularly on fertility. In this study, we demonstrated the cross talk between downstream signaling of CLA and important hormone regulators of endocrine system, i.e. FSH and IGF1, on buffalo granulosa cell function (proliferation and steroidogenesis). Experiments were performed in primary serum-free buffalo granulosa cell culture, where cells were incubated with CLA in combination with FSH (25 ng/ml) and IGF1 (50  ng/ml). Results showed that 10 μM CLA inhibits FSH- and IGF1-induced granulosa cell proliferation; aromatase, GATA4, and IGF1 mRNA; and estradiol-17β production. Western blot analysis of total cell lysates revealed that CLA intervenes the IGF1 signaling by decreasing p-Akt. In addition, CLA was found to upregulate peroxisome proliferator-activated receptor-gamma (PPARG) and phosphatase and tensin homolog (PTEN) level in granulosa cells. Further study using PPARG- and PTEN-specific inhibitors supports the potential role of CLA in granulosa cell proliferation and steroidogenesis involving PPARG, PTEN, and PI3K/Akt pathway.

  11. ROS constitute a convergence nexus in the development of IGF1 resistance and impaired wound healing in a rat model of type 2 diabetes

    PubMed Central

    Bitar, Milad S.; Al-Mulla, Fahd

    2012-01-01

    SUMMARY An indolent non-healing wound and insulin and/or insulin-like growth factor (IGF1) resistance are cardinal features of diabetes, inflammation and hypercortisolemia. Little is known about why these phenomena occur in so many contexts. Do the various triggers that induce insulin and/or IGF1 resistance and retard wound healing act through a common mechanism? Cultured dermal fibroblasts from rats and full-thickness excisional wounds were used as models to test the premise that reactive oxygen species (ROS) play a causal role in the development of IGF1 resistance and impaired wound healing under different but pathophysiologically relevant clinical settings, including diabetes, dexamethasone-induced hypercortisolemia and TNFα-induced inflammation. In normal fibroblasts, IGF1 initiated a strong degree of phosphorylation of insulin receptor substrate 1 (IRS1) (Tyr612) and Akt (Ser473), concomitantly with increased PI3K activity. This phenomenon seemed to be attenuated in fibroblasts that had phenotypic features of diabetes, inflammation or hypercortisolemia. Notably, these cells also exhibited an increase in the activity of the ROS–phospho-JNK (p-JNK)–p-IRS1 (Ser307) axis. The above-mentioned defects were reflected functionally by attenuation in IGF1-dependent stimulation of key fibroblast functions, including collagen synthesis and cell proliferation, migration and contraction. The effects of IGF1 on glucose disposal and cutaneous wound healing were also impaired in diabetic or hypercortisolemic rats. The ROS suppressors EUK-134 and α-lipoic acid, or small interfering RNA (siRNA)-mediated silencing of JNK expression, restored IGF1 sensitivity both in vitro and in vivo, and also ameliorated the impairment in IGF1-mediated wound responses during diabetes, inflammation and hypercortisolemia. Our data advance the notion that ROS constitute a convergence nexus for the development of IGF1 resistance and impaired wound healing under different but

  12. Overload training inhibits phagocytosis and ROS generation of peritoneal macrophages: role of IGF-1 and MGF.

    PubMed

    Xiao, Weihua; Chen, Peijie; Wang, Ru; Dong, Jingmei

    2013-01-01

    We tested the hypothesis that overload training inhibits the phagocytosis and the reactive oxygen species (ROS) generation of peritoneal macrophages (Mϕs), and that insulin-like growth factor-1(IGF-1) and mechano-growth factor (MGF) produced by macrophages may contribute to this process. Rats were randomized to two groups, sedentary control group (n = 10) and overload training group (n = 10). The rats of overload training group were subjected to 11 weeks of experimental training protocol. Blood sample was used to determine the content of hemoglobin, testosterone, and corticosterone. The phagocytosis and the ROS generation of Mϕs were measured by the uptake of neutral red and the flow cytometry, respectively. IGF-1 and MGF mRNA levels in Mϕs were determined by real-time PCR. In addition, we evaluated the effects of IGF-1 and MGF peptide on phagocytosis and ROS generation of Mϕs in vitro. The data showed that overload training significantly decreased the body weight (19.3 %, P < 0.01), the hemoglobin (13.5 %, P < 0.01), the testosterone (55.3 %, P < 0.01) and the corticosterone (40.6 %, P < 0.01) in blood. Moreover, overload training significantly decreased the phagocytosis (27 %, P < 0.05) and the ROS generation (35 %, P < 0.01) of Mϕs. IGF-1 and MGF mRNA levels in Mϕs from overload training group increased significantly compared with the control group (21-fold and 92-fold, respectively; P < 0.01). In vitro experiments showed that IGF-1 had no significant effect on the phagocytosis and the ROS generation of Mϕs. Unlike IGF-1, MGF peptide impaired the phagocytosis of Mϕs in dose-independent manner. In addition, MGF peptide of some concentrations (i.e., 1, 10, 50, 100 ng/ml) significantly inhibited the ROS generation of Mϕs. These results suggest that overload training inhibits the phagocytosis and the ROS generation of peritoneal macrophages, and that MGF produced by macrophages may play a key role in this process. This may represent a novel mechanism of

  13. Igf1 and Pacap rescue cerebellar granule neurons from apoptosis via a common transcriptional program

    PubMed Central

    Maino, B; D’Agata, V; Severini, C; Ciotti, MT; Calissano, P; Copani, A; Chang, Y-C; DeLisi, C; Cavallaro, S

    2015-01-01

    A shift of the delicate balance between apoptosis and survival-inducing signals determines the fate of neurons during the development of the central nervous system and its homeostasis throughout adulthood. Both pathways, promoting or protecting from apoptosis, trigger a transcriptional program. We conducted whole-genome expression profiling to decipher the transcriptional regulatory elements controlling the apoptotic/survival switch in cerebellar granule neurons following the induction of apoptosis by serum and potassium deprivation or their rescue by either insulin-like growth factor-1 (Igf1) or pituitary adenylyl cyclase-activating polypeptide (Pacap). Although depending on different upstream signaling pathways, the survival effects of Igf1 and Pacap converged into common transcriptional cascades, thus suggesting the existence of a general transcriptional program underlying neuronal survival. PMID:26941962

  14. The lack of effect of specific overexpression of IGF-1 in the central nervous system or skeletal muscle on pathophysiology in the G93A SOD-1 mouse model of ALS.

    PubMed

    Messi, Maria Laura; Clark, Heather M; Prevette, David M; Oppenheim, Ronald W; Delbono, Osvaldo

    2007-09-01

    The ability of insulin like growth factor 1 (IGF-1) to prevent the pathophysiology associated with amyotrophic lateral sclerosis (ALS) is currently being explored with animal models and in clinical trials with patients. Several studies have reported positive effects of IGF-1 in reducing motor neuron death, delaying the onset of motor performance decline, and increasing life span, in SOD-1 mouse models of ALS and in one clinical trial. However, a second clinical trial produced no positive results raising questions about the therapeutic efficacy of IGF-1. To investigate the effect of specific and sustained IGF-1 expression in skeletal muscle or central nervous system on motor performance, life span, and motor neuron survival, human-IGF-1 transgenic mice were crossed with the G93A SOD-1 mutant model of ALS. No significant differences were found in onset of motor performance decline, life span, or motor neuron survival in the spinal cord, between SOD+/IGF-1+ and SOD+/IGF-1- hybrid mice. IGF-1 concentration levels, measured by radioimmunoassay, were found to be highly increased throughout life in the central nervous system (CNS) and skeletal muscle of IGF-1 transgenic hybrid mice. Additionally, increased CNS weight in SOD+ mice crossbred with CNS IGF-1 transgenic mice demonstrates that IGF-1 overexpression is biologically active even after the disease is fully developed. Taken together, these results raise questions concerning the therapeutic value of IGF-1 and indicate that further studies are needed to examine the relationship between methods of IGF-1 administration and its potential therapeutic value.

  15. Overexpression of decorin promoted angiogenesis in diabetic cardiomyopathy via IGF1R-AKT-VEGF signaling.

    PubMed

    Lai, Jinsheng; Chen, Fuqiong; Chen, Jing; Ruan, Guoran; He, Mengying; Chen, Chen; Tang, Jiarong; Wang, Dao Wen

    2017-03-14

    Microcirculatory dysfunction is believed to play an important role in diabetic cardiomyopathy. The small leucine-rich proteoglycan decorin is generally considered a pro-angiogenic factor. Here, we investigate whether overexpression of decorin ameliorates diabetic cardiomyopathy and its effects on angiogenesis in vivo and in vitro. Diabetes was induced through intraperitoneal injection with streptozotocin combined with a high-fat diet, and decorin was overexpressed via recombinant adeno-associated virus in Wistar rats. Six months later, cardiac function was determined using an echocardiography and cardiac catheter system. The results showed that cardiac function was decreased in diabetic rats and restored by overexpression of decorin. In addition, overexpression of decorin upregulated the expression of VEGF and attenuated the reduction in the cardiac capillary density. In the in vitro study, high glucose induced apoptosis and inhibited the capabilities of tube formation, migration and proliferation, which were all ameliorated by decorin overexpression. Meanwhile, decorin overexpression increased the expression of VEGF and IGF1R, as well as the phosphorylation level of AKT and AP-1. Nonetheless, all of these effects were abolished by pretreatment with the IGF1R antibody or AKT inhibitor. In conclusion, overexpression of decorin ameliorated diabetic cardiomyopathy and promoted angiogenesis through the IGF1R-AKT-VEGF signaling pathway in vivo and in vitro.

  16. Overexpression of decorin promoted angiogenesis in diabetic cardiomyopathy via IGF1R-AKT-VEGF signaling

    PubMed Central

    Lai, Jinsheng; Chen, Fuqiong; Chen, Jing; Ruan, Guoran; He, Mengying; Chen, Chen; Tang, Jiarong; Wang, Dao Wen

    2017-01-01

    Microcirculatory dysfunction is believed to play an important role in diabetic cardiomyopathy. The small leucine-rich proteoglycan decorin is generally considered a pro-angiogenic factor. Here, we investigate whether overexpression of decorin ameliorates diabetic cardiomyopathy and its effects on angiogenesis in vivo and in vitro. Diabetes was induced through intraperitoneal injection with streptozotocin combined with a high-fat diet, and decorin was overexpressed via recombinant adeno-associated virus in Wistar rats. Six months later, cardiac function was determined using an echocardiography and cardiac catheter system. The results showed that cardiac function was decreased in diabetic rats and restored by overexpression of decorin. In addition, overexpression of decorin upregulated the expression of VEGF and attenuated the reduction in the cardiac capillary density. In the in vitro study, high glucose induced apoptosis and inhibited the capabilities of tube formation, migration and proliferation, which were all ameliorated by decorin overexpression. Meanwhile, decorin overexpression increased the expression of VEGF and IGF1R, as well as the phosphorylation level of AKT and AP-1. Nonetheless, all of these effects were abolished by pretreatment with the IGF1R antibody or AKT inhibitor. In conclusion, overexpression of decorin ameliorated diabetic cardiomyopathy and promoted angiogenesis through the IGF1R-AKT-VEGF signaling pathway in vivo and in vitro. PMID:28290552

  17. Cerebellar Insulin/IGF-1 signaling in diabetic rats: Effects of exercise training.

    PubMed

    Borges, Mariana Eiras; Ribeiro, Alessandra Mussi; Pauli, José Rodrigo; Arantes, Luciana Mendonça; Luciano, Eliete; de Moura, Leandro Pereira; de Almeida Leme, José Alexandre Curiacos; Medeiros, Alessandra; Bertolini, Natália Oliveira; Sibuya, Clarice Yoshiko; Gomes, Ricardo José

    2017-02-03

    The Diabetes Mellitus (DM) is a chronic disease associated with loss of brain regions such as the cerebellum, increasing the risk of developing neurodegenerative diseases such as Parkinson's disease (PD). In the brain of diabetic and PD organisms the insulin/IGF-1 signaling is altered. Exercise training is an effective intervention for the prevention of neurodegerative diseases since it release neurotrophic factors and regulating insulin/IGF-1 signaling in the brain. This study aimed to evaluate the proteins involved in the insulin/IGF-1 pathway in the cerebellum of diabetic rats subjected to exercise training protocol. Wistar rats were distributed in four groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced by Alloxan (ALX) (32mg/kgb.w.). The training program consisted in swimming 5days/week, 1h/day, during 6 weeks, supporting an overload corresponding to 90% of the anaerobic threshold. At the end, cerebellum was extracted to determinate the protein expression of GSK-3β, IRβ and IGF-1R and the phosphorylation of β-amyloid, Tau, ERK1+ERK2 by Western Blot analysis. All dependent variables were analyzed by one-way analysis of variance with significance level of 5%. Diabetes causes hyperglycemia in both diabetic groups; however, in TD, there was a reduction in hyperglycemia compared to SD. Diabetes increased Tau and β-amyloid phosphorylation in both SD and TD groups. Furthermore, aerobic exercise increased ERK1+ERK2 expression in TC. The data showed that in cerebellum of diabetic rats induced by alloxan there are some proteins expression like Parkinson cerebellum increased, and the exercise training was not able to modulate the expression of these proteins.

  18. Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

    SciTech Connect

    Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

    2011-07-08

    Highlights: {yields} We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. {yields} We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. {yields} We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. {yields} Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 {+-} 6% and by liposomal magnetofection by 85.1 {+-} 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the

  19. MiRNA-181b suppresses IGF-1R and functions as a tumor suppressor gene in gliomas.

    PubMed

    Shi, Zhu-Mei; Wang, Xie-Feng; Qian, Xu; Tao, Tao; Wang, Lin; Chen, Qiu-Dan; Wang, Xi-Rui; Cao, Lei; Wang, Ying-Yi; Zhang, Jun-Xia; Jiang, Tao; Kang, Chun-Sheng; Jiang, Bing-Hua; Liu, Ning; You, Yong-Ping

    2013-04-01

    MicroRNAs (miRNAs) are single-stranded, 18- to 23-nt RNA molecules that function as regulators of gene expression. Previous studies have shown that microRNAs play important roles in human cancers, including gliomas. Here, we found that expression levels of miR-181b were decreased in gliomas, and we identified IGF-1R as a novel direct target of miR-181b. MiR-181b overexpression inhibited cell proliferation, migration, invasion, and tumorigenesis by targeting IGF-1R and its downstream signaling pathways, PI3K/AKT and MAPK/ERK1/2. Overexpression of IGF-1R rescued the inhibitory effects of miR-181b. In clinical specimens, IGF-1R was overexpressed, and its protein levels were inversely correlated with miR-181b expression. Taken together, our results indicate that miR-181b functions in gliomas to suppress growth by targeting the IGF-1R oncogene and that miR-181b may serve as a novel therapeutic target for gliomas.

  20. Possible role of the Ec peptide of IGF-1Ec in cartilage repair

    PubMed Central

    Armakolas, Nikolaos; Dimakakos, Andreas; Armakolas, Athanasios; Antonopoulos, Athanasios; Koutsilieris, Michael

    2016-01-01

    The Ec peptide (PEc) of insulin-like growth factor 1 Ec (IGF-1Ec) induces human mesenchymal stem cell (hMSC) mobilization and activates extracellular signal-regulated kinase 1/2 (ERK 1/2) in various cells. The aim of the present study was to examine the effects of PEc on the mobilization and differentiation of hMSCs, as well as the possibility of its implementation in combination with transforming growth factor β1 (TGF-β1) for cartilage repair. The effects of the exogenous administration of PEc and TGF-β1, alone and in combination, on hMSCs were assessed using a trypan blue assay, reverse transcription-quantitative polymerase chain reaction, western blot analysis, Alcian blue staining, wound healing assays and migration/invasion assays. It was determined that PEc is involved in the differentiation process of hMSCs towards hyaline cartilage. Treatment of hMSCs with either PEc, TGF-β1 or both, demonstrated comparable cartilage matrix deposition. Furthermore, treatment with PEc in combination with TGF-β1 was associated with a significant increase in hMSC mobilization when compared with treatment with TGF-β1 or PEc alone (P<0.05). Thus, PEc appears to facilitate in vitro hMSC mobilization and differentiation towards chondrocytes, enhancing the role of TGF-β1. PMID:27571686

  1. Association between genetic variations in the insulin/insulin-like growth factor (Igf-1) signaling pathway and longevity: a systematic review and meta-analysis.

    PubMed

    Di Bona, Danilo; Accardi, Giulia; Virruso, Claudia; Candore, Giuseppina; Caruso, Calogero

    2014-01-01

    Some studies have shown that polymorphisms in the insulin growth factor-1 (IGF-1) signaling pathway genes could influence human longevity. However, the results of different studies are often inconsistent. Our aim was to investigate by systematic review and meta-analysis the association of the common polymorphisms defining the genetic variability of the IGF-1 signaling pathway associated with human longevity. Eleven studies investigating the association between the polymorphisms in the IGF-1 signaling pathway genes (IGF-1, IGF-1 receptor (IGF-1R), Forkhead box O3A (FOXO3A) and Silent mating type Information Regulation 1 (SIRT1) and longevity were found and analyzed. The modelfree approach was applied to meta-analyze these studies. No association was reported between the single nucleotide polymorphisms (SNPs) of IGF-1 and longevity in the only available study. The meta-analysis of available data from four studies, showed a significant association with the IGF-1R polymorphism rs2229765, suggesting that subjects with the Abearing genotype have a greater chance of longevity. Concerning the five studies on FOXO3A SNPs, for the rs2764264 a significant association with longevity was observed for C allele when only males were included in the analysis. Statistically significant results were obtained for other SNPs as well, i.e. rs2802292 (G allele), rs9400239 and rs479744 (T and A alleles, respectively). For rs9400239 the association was observed in long lived males with a lower odds ratio than in centenarians, while in rs479744 a significant association was highlighted in centenarians. Concerning SIRT1, no association between the SNPs under study and longevity was observed in the only available report. Current findings suggest that both IGF-1R and FOXO3A polymorphisms could be associated with longevity. The high degree of between-study heterogeneity and the low number of available studies underline the need for further methodologically adequate analyses to confirm this

  2. Whole body hypothermia broadens the therapeutic window of intranasally administered IGF-1 in a neonatal rat model of cerebral hypoxia-ischemia

    PubMed Central

    Lin, Shuying; Rhodes, Philip G.; Cai, Zhengwei

    2011-01-01

    To investigate whether whole body hypothermia after neonatal cerebral hypoxia-ischemia (HI) could broaden the therapeutic window of intranasal treatment of IGF-1 (iN-IGF-1), postnatal day 7 rat pups were subjected to right common carotid artery ligation, followed by 8% oxygen inhalation for 2 h. After HI, one group of pups were returned to their dams and kept at room temperature (24.5±0.2°C). A second group of pups were subjected to whole body hypothermia in a cool environment (21.5±0.3°C) for 2 or 4 h before being returned to their dams. Two doses of 50 μg recombinant human IGF-1 were administered intranasally at a 1 h interval starting at 0, 2 or 4 h after hypothermia. Hypothermia decreased the rectal temperature of pups by 4.5°C as compared to those kept at room temperature. While hypothermia or iN-IGF-1 administered 2 h after HI alone did not provide neuroprotection, the combined treatment of hypothermia with iN-IGF-1 significantly protected the neonatal rat brain from HI injury. Hypothermia treatment extended the therapeutic window of IGF-1 to 6 h after HI. The extended IGF-1 therapeutic window by hypothermia was associated with decreases in infiltration of polymorphonuclear leukocytes and activation of microglia/macrophages and with attenuation of NF-κB activation in the ipsilateral hemisphere following HI. PMID:21316352

  3. Improvement of Eye Alignment in Adult Strabismic Monkeys by Sustained IGF-1 Treatment

    PubMed Central

    McLoon, Linda K.; Christiansen, Stephen P.; Ghose, Geoffrey M.; Das, Vallabh E.; Mustari, Michael J.

    2016-01-01

    Purpose The goal of this study was to determine if continuous application of insulin-like growth factor-1 (IGF-1) could improve eye alignment of adult strabismic nonhuman primates and to assess possible mechanisms of effect. Methods A continuous release pellet of IGF-1 was placed on one medial rectus muscle in two adult nonhuman primates (M1, M2) rendered exotropic by the alternating monocular occlusion method during the first months of life. Eye alignment and eye movements were recorded for 3 months, after which M1 was euthanized, and the lateral and medial rectus muscles were removed for morphometric analysis of fiber size, nerve, and neuromuscular density. Results Monkey 1 showed a 40% reduction in strabismus angle, a reduction of exotropia of approximately 11° to 14° after 3 months. Monkey 2 showed a 15% improvement, with a reduction of its exotropia by approximately 3°. The treated medial rectus muscle of M1 showed increased mean myofiber cross-sectional areas. Increases in myofiber size also were seen in the contralateral medial rectus and lateral rectus muscles. Similarly, nerve density increased in the contralateral medial rectus and yoked lateral rectus. Conclusions This study demonstrates that in adult nonhuman primates with a sensory-induced exotropia in infancy, continuous IGF-1 treatment improves eye alignment, resulting in muscle fiber enlargement and altered innervational density that includes the untreated muscles. This supports the view that there is sufficient plasticity in the adult ocular motor system to allow continuous IGF-1 treatment over months to produce improvement in eye alignment in early-onset strabismus. PMID:27820875

  4. Repression of Igf1 expression by Ezh2 prevents basal cell differentiation in the developing lung

    PubMed Central

    Galvis, Laura A.; Holik, Aliaksei Z.; Short, Kieran M.; Pasquet, Julie; Lun, Aaron T. L.; Blewitt, Marnie E.; Smyth, Ian M.; Ritchie, Matthew E.; Asselin-Labat, Marie-Liesse

    2015-01-01

    Epigenetic mechanisms involved in the establishment of lung epithelial cell lineage identities during development are largely unknown. Here, we explored the role of the histone methyltransferase Ezh2 during lung lineage determination. Loss of Ezh2 in the lung epithelium leads to defective lung formation and perinatal mortality. We show that Ezh2 is crucial for airway lineage specification and alveolarization. Using optical projection tomography imaging, we found that branching morphogenesis is affected in Ezh2 conditional knockout mice and the remaining bronchioles are abnormal, lacking terminally differentiated secretory club cells. Remarkably, RNA-seq analysis revealed the upregulation of basal genes in Ezh2-deficient epithelium. Three-dimensional imaging for keratin 5 further showed the unexpected presence of a layer of basal cells from the proximal airways to the distal bronchioles in E16.5 embryos. ChIP-seq analysis indicated the presence of Ezh2-mediated repressive marks on the genomic loci of some but not all basal genes, suggesting an indirect mechanism of action of Ezh2. We found that loss of Ezh2 de-represses insulin-like growth factor 1 (Igf1) expression and that modulation of IGF1 signaling ex vivo in wild-type lungs could induce basal cell differentiation. Altogether, our work reveals an unexpected role for Ezh2 in controlling basal cell fate determination in the embryonic lung endoderm, mediated in part by repression of Igf1 expression. PMID:25790853

  5. The association between IGF-1 polymorphisms and high myopia

    PubMed Central

    Zhang, Xiaoyu; Zhou, Xingtao; Qu, Xinhua

    2015-01-01

    Background: The potential association between IGF-1 polymorphisms and high myopia has been investigated in previous studies, but the actual relationship remains controversial. Accordingly, we conducted a meta-analysisincludingcase-control and cohort studies to assess the existing relationship between high myopia and IGF-1 polymorphisms. We searched MEDLINE, EMBASE, and OVID. Odds ratios (OR) with 95% confidence intervals (CI) were derived for single-nucleotide polymorphisms (SNPs) involved in the studies obtained from the retrospective database search. Analyses of heterogeneity, sensitivity, and publication bias were also conducted. The findings from this meta-analysis were based on approximately 2,187 high myopia cases and 1,183 controls, and were used to assess the association between three IGF-1 genetic polymorphisms (rs6214, rs12423791, and rs5742632) and high myopia risks. We investigated the association of the IGF-1 gene SNP rs6214, but no statistical association was observed in the resulting odds ratios (OR) in the allelic (OR = 1.06, 95% CI = 0.89-1.25), dominant (OR = 1.07, 95% CI = 0.90-1.27), or recessive models (OR = 1.06, 95% CI = 0.89-1.26), or in the homozygote (OR = 1.12, 95% CI = 0.91-1.38) and heterozygote comparisons (OR = 1.06, 95% CI = 0.88-1.27). Simultaneously, two other selected SNPs, rs12423791 and rs5742632, were also studied, but similarly, no statistical association existed between these polymorphisms and the risk of high myopia. In conclusions, no statistical association between IGF-1 polymorphisms (rs6214, rs12423791, and rs5742632) and the risk of high myopia was observed following the reported meta-analysis. PMID:26309715

  6. DNA Methylation Changes in the IGF1R Gene in Birth Weight Discordant Adult Monozygotic Twins.

    PubMed

    Tsai, Pei-Chien; Van Dongen, Jenny; Tan, Qihua; Willemsen, Gonneke; Christiansen, Lene; Boomsma, Dorret I; Spector, Tim D; Valdes, Ana M; Bell, Jordana T

    2015-12-01

    Low birth weight (LBW) can have an impact on health outcomes in later life, especially in relation to pre-disposition to metabolic disease. Several studies suggest that LBW resulting from restricted intrauterine growth leaves a footprint on DNA methylation in utero, and this influence likely persists into adulthood. To investigate this further, we performed epigenome-wide association analyses of blood DNA methylation using Infinium HumanMethylation450 BeadChip profiles in 71 adult monozygotic (MZ) twin pairs who were extremely discordant for birth weight. A signal mapping to the IGF1R gene (cg12562232, p = 2.62 × 10(-8)), was significantly associated with birth weight discordance at a genome-wide false-discovery rate (FDR) of 0.05. We pursued replication in three additional independent datasets of birth weight discordant MZ pairs and observed the same direction of association, but the results were not significant. However, a meta-analysis across the four independent samples, in total 216 birth-weight discordant MZ twin pairs, showed a significant positive association between birth weight and DNA methylation differences at IGF1R (random-effects meta-analysis p = .04), and the effect was particularly pronounced in older twins (random-effects meta-analysis p = .008, 98 older birth-weight discordant MZ twin pairs). The results suggest that severe intra-uterine growth differences (birth weight discordance >20%) are associated with methylation changes in the IGF1R gene in adulthood, independent of genetic effects.

  7. IGF-1R Regulates the Extracellular Level of Active MMP-2, Pathological Neovascularization, and Functionality in Retinas of OIR Mouse Model.

    PubMed

    Lorenc, Valeria E; Subirada Caldarone, Paula V; Paz, María C; Ferrer, Darío G; Luna, José D; Chiabrando, Gustavo A; Sánchez, María C

    2017-01-17

    In ischemic proliferative diseases such as retinopathies, persistent hypoxia leads to the release of numerous neovascular factors that participate in the formation of abnormal vessels and eventually cause blindness. The upregulation and activation of metalloproteinases (MMP-2 and MMP-9) represent a final common pathway in this process. Although many regulators of the neovascular process have been identified, the complete role of the insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) appears to be significantly more complex. In this study, we used an oxygen-induced retinopathy (OIR) mouse model as well as an in vitro model of hypoxia to study the role of MMP-2 derived from Müller glial cells (MGCs) and its relation with the IGF-1/IGF-1R system. We demonstrated that MMP-2 protein expression increased in P17 OIR mice, which coincided with the active phase of the neovascular process. Also, glutamine synthetase (GS)-positive cells were also positive for MMP-2, whereas IGF-1R was expressed by GFAP-positive cells, indicating that both proteins were expressed in MGCs. In addition, in the OIR model a single intravitreal injection of the IGF-1R blocking antibody (αIR3) administered at P12 effectively prevented pathologic neovascularization, accelerated physiological revascularization, and improved retinal functionality at P17. Finally, in MGC supernatants, the blocking antibody abolished the IGF-1 effect on active MMP-2 under normoxic and hypoxic conditions without affecting the extracellular levels of pro-MMP-2. These results demonstrate, for the first time, that the IGF-1/IGF-1R system regulates active MMP-2 levels in MGCs, thus contributing to MEC remodeling during the retinal neovascular process.

  8. The correlation between insulin-like growth factor 1 (IGF-1) and novel adipocytokines in postmenopausal women: A population-based study.

    PubMed

    Darabi, Hossein; Ostovar, Afshin; Raeisi, Alireza; Kalantarhormozi, Mohammad Reza; Assadi, Majid; Akbarzadeh, Samad; Momeni, Safieh; Dobaradaran, Sina; Vahdat, Katayoun; Nabipour, Iraj

    2017-03-13

    The adipocytokines and insulin-like growth factor 1 (IGF-1) are involved in insulin resistance, the cardiometabolic syndrome, and atherosclerosis. Therefore, investigating the relationship between circulating levels of the novel adipocytokines and IGF-1 is worthwhile. The correlation between IGF-1, visfatin, and omentin-1 has not been adequately investigated. In a population-based study, 324 postmenopausal women were randomly selected. Circulating IGF-1, visfatin, omentin-1, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) levels were measured with the highly specific enzyme-linked immunosorbent assay method. In multiple regression analyses adjusted for alkaline phosphatase, osteocalcin, and hs-CRP, circulating IGF-1 was significantly correlated with visfatin levels (standardized β coefficient [β] = 0.13, partial correlation coefficient [r] = 0.12, p = 0.028). The significant positive correlation between serum IGF-1 and visfatin levels remained after additional adjustments for age and BMI (β = 0.12, r = 0.12, p = 0.025), metabolic syndrome (β = 0.13, r = 0.12, p = 0.021), and type 2 diabetes mellitus (β = 0.13, r = 0.12, p = 0.026). No significant correlations were found between IGF-1, adiponectin, and omentin-1. There is a significant correlation between serum IGF-1 and visfatin levels in postmenopausal women beyond metabolic syndrome, type 2 diabetes, bone formation markers, and hs-CRP levels. The observed correlation between higher circulating IGF-1 and the higher visfatin levels might be a physiological compensation and adaptation to protect against visfatin-induced proinflammatory effects.

  9. Low dose IR-induced IGF-1-sCLU expression: a p53-repressed expression cascade that interferes with TGFβ1 signaling to confer a pro-survival bystander effect.

    PubMed

    Klokov, D; Leskov, K; Araki, S; Zou, Y; Goetz, E M; Luo, X; Willson, D; Boothman, D A

    2013-01-24

    Inadvertent mammalian tissue exposures to low doses of ionizing radiation (IR) after radiation accidents, remediation of radioactive-contaminated areas, space travel or a dirty bomb represent an interesting trauma to an organism. Possible low-dose IR-induced bystander effects could impact our evaluation of human health effects, as cells within tissue are not equally damaged after doses of IR ≤10 cGy. To understand tissue responses after low IR doses, we generated a reporter system using the human clusterin promoter fused to firefly luciferase (hCLUp-Luc). Secretory clusterin (sCLU), an extracellular molecular chaperone, induced by low doses of cytotoxic agents, clears cell debris. Low-dose IR (≥2 cGy) exposure induced hCLUp-Luc activity with peak levels at 96 h, consistent with endogenous sCLU levels. As doses increased (≥1 Gy), sCLU induction amplitudes increased and time-to-peak response decreased. sCLU expression was stimulated by insulin-like growth factor-1, but suppressed by p53. Responses in transgenic hCLUp-Luc reporter mice after low IR doses showed that specific tissues (that is, colon, spleen, mammary, thymus and bone marrow) of female mice induced hCLUp-Luc activity more than male mice after whole body (≥10 cGy) irradiation. Tissue-specific, non-linear dose- and time-responses of hCLUp-Luc and endogenous sCLU levels were noted. Colon maintained homeostatic balance after 10 cGy. Bone marrow responded with delayed, but prolonged and elevated expression. Intraperitoneal administration of α-transforming growth factor (TGF)β1 (1D11), but not control (13C4) antibodies, immediately following IR exposure abrogated CLU induction responses. Induction in vivo also correlated with Smad signaling by activated TGFβ1 after IR. Mechanistically, media with elevated sCLU levels suppressed signaling, blocked apoptosis and increased survival of TGFβ1-exposed tumor or normal cells. Thus, sCLU is a pro-survival bystander factor that abrogates TGFβ1

  10. Combination of Anti-IGF-1R Antibody A12 and Ionizing Radiation in Upper Respiratory Tract Cancers

    SciTech Connect

    Riesterer, Oliver; Yang Qiuan; Raju, Uma; Torres, Mylin; Molkentine, David; Patel, Nalini; Valdecanas, David; Milas, Luka; Ang, K. Kian

    2011-03-15

    Purpose: The IGF1/IGF-1R signaling pathway has emerged as a potential determinant of radiation resistance in human cancer cell lines. Therefore we investigated the potency of monoclonal anti-IGF-1R antibody, A12, to enhance radiation response in upper respiratory tract cancers. Methods and Materials: Cell lines were assessed for IGF-1R expression and IGF1-dependent response to A12 or radiation using viability and clonogenic cancer cell survival assays. In vivo response of tumor xenografts to 10 or 20 Gy and A12 (0.25-2 mg x 3) was assessed using growth delay assays. Combined treatment effects were also analyzed by immunohistochemical assays for tumor cell proliferation, apoptosis, necrosis, and vascular endothelial growth factor expression at Days 1 and 6 after start of treatment. Results: A12 enhanced the radiosensitivity of HN5 and FaDu head-and-neck carcinomas in vitro (p < 0.05) and amplified the radioresponse of FaDu xenografts in a dose-dependent manner, with enhancement factors ranging from 1.2 to 1.8 (p < 0.01). Immunohistochemical analysis of FaDu xenografts demonstrated that A12 inhibited tumor cell proliferation (p < 0.05) and vascular endothelial growth factor expression. When A12 was combined with radiation, this resulted in apoptosis induction that persisted until 6 days from the start of treatment and in increased necrosis at Day 1 (p < 0.01, respectively). Combined treatment with A12 and radiation resulted in additive or subadditive growth delay in H460 or A549 xenografts, respectively. Conclusions: The results of this study strengthen the evidence for investigating how anti-IGF-1R strategies can be integrated into radiation and radiation-cetuximab regimen in the treatment of cancer of the upper aerodigestive tract cancers.

  11. Noncanonical control of C. elegans germline apoptosis by the insulin/IGF-1 and Ras/MAPK signaling pathways

    PubMed Central

    Perrin, A J; Gunda, M; Yu, B; Yen, K; Ito, S; Forster, S; Tissenbaum, H A; Derry, W B

    2013-01-01

    The insulin/IGF-1 pathway controls a number of physiological processes in the nematode worm Caenorhabditis elegans, including development, aging and stress response. We previously found that the Akt/PKB ortholog AKT-1 dampens the apoptotic response to genotoxic stress in the germline by negatively regulating the p53-like transcription factor CEP-1. Here, we report unexpected rearrangements to the insulin/IGF-1 pathway, whereby the insulin-like receptor DAF-2 and 3-phosphoinositide-dependent protein kinase PDK-1 oppose AKT-1 to promote DNA damage-induced apoptosis. While DNA damage does not affect phosphorylation at the PDK-1 site Thr350/Thr308 of AKT-1, it increased phosphorylation at Ser517/Ser473. Although ablation of daf-2 or pdk-1 completely suppressed akt-1-dependent apoptosis, the transcriptional activation of CEP-1 was unaffected, suggesting that daf-2 and pdk-1 act independently or downstream of cep-1 and akt-1. Ablation of the akt-1 paralog akt-2 or the downstream target of the insulin/IGF-1 pathway daf-16 (a FOXO transcription factor) restored sensitivity to damage-induced apoptosis in daf-2 and pdk-1 mutants. In addition, daf-2 and pdk-1 mutants have reduced levels of phospho-MPK-1/ERK in their germ cells, indicating that the insulin/IGF-1 pathway promotes Ras signaling in the germline. Ablation of the Ras effector gla-3, a negative regulator of mpk-1, restored sensitivity to apoptosis in daf-2 mutants, suggesting that gla-3 acts downstream of daf-2. In addition, the hypersensitivity of let-60/Ras gain-of-function mutants to damage-induced apoptosis was suppressed to wild-type levels by ablation of daf-2. Thus, insulin/IGF-1 signaling selectively engages AKT-2/DAF-16 to promote DNA damage-induced germ cell apoptosis downstream of CEP-1 through the Ras pathway. PMID:22935616

  12. Cortisol and IGF-1 synergistically up-regulate taurine transport by the rat skeletal muscle cell line, L6.

    PubMed

    Park, Sung-Hee; Lee, Haemi; Park, Taesun

    2004-01-01

    This study was undertaken to evaluate effects of exercise-induced hormones, cortisol, IGF-1, and beta-endorphin, on the regulation of taurine transport activity in rat skeletal myoblasts, L6 cells. Challenge of L6 cells with cortisol (100 nM) for 24 hrs resulted in a 165% increase in taurine transport activity, 220% increase in Vmax of the taurine transporter, and 55% increase in taurine transporter/ beta-actin mRNA level compared with untreated control cells. Neither IGF-1 (1 approximately 100 nM) nor beta-endorphin (1 approximately 20 nM), added in the incubation medium separately for 24 hrs, affected taurine uptake by L6 cells. However, when cells were co-treated with IGF-1 (10 nM) plus cortisol (100 nM), taurine transport activity (37% increase, p < 0.05), Vmax of the transporter (54%, p < 0.05), and taurine transporter/ beta-actin mRNA level were further increased compared to the value for cells treated with cortisol alone. These results suggest that taurine transport by skeletal muscle cells appear to be synergistically up-regulated during a prolonged exercise via elevated levels of cortisol and IGF-1 in muscle.

  13. Exercise Activates p53 and Negatively Regulates IGF-1 Pathway in Epidermis within a Skin Cancer Model

    PubMed Central

    Yu, Miao; King, Brenee; Ewert, Emily; Su, Xiaoyu; Mardiyati, Nur; Zhao, Zhihui; Wang, Weiqun

    2016-01-01

    Exercise has been previously reported to lower cancer risk through reducing circulating IGF-1 and IGF-1-dependent signaling in a mouse skin cancer model. This study aims to investigate the underlying mechanisms by which exercise may down-regulate the IGF-1 pathway via p53 and p53-related regulators in the skin epidermis. Female SENCAR mice were pair-fed an AIN-93 diet with or without 10-week treadmill exercise at 20 m/min, 60 min/day and 5 days/week. Animals were topically treated with TPA 2 hours before sacrifice and the target proteins in the epidermis were analyzed by both immunohistochemistry and Western blot. Under TPA or vehicle treatment, MDM2 expression was significantly reduced in exercised mice when compared with sedentary control. Meanwhile, p53 was significantly elevated. In addition, p53-transcriptioned proteins, i.e., p21, IGFBP-3, and PTEN, increased in response to exercise. There was a synergy effect between exercise and TPA on the decreased MDM2 and increased p53, but not p53-transcripted proteins. Taken together, exercise appeared to activate p53, resulting in enhanced expression of p21, IGFBP-3, and PTEN that might induce a negative regulation of IGF-1 pathway and thus contribute to the observed cancer prevention by exercise in this skin cancer model. PMID:27509024

  14. Exercise Activates p53 and Negatively Regulates IGF-1 Pathway in Epidermis within a Skin Cancer Model.

    PubMed

    Yu, Miao; King, Brenee; Ewert, Emily; Su, Xiaoyu; Mardiyati, Nur; Zhao, Zhihui; Wang, Weiqun

    2016-01-01

    Exercise has been previously reported to lower cancer risk through reducing circulating IGF-1 and IGF-1-dependent signaling in a mouse skin cancer model. This study aims to investigate the underlying mechanisms by which exercise may down-regulate the IGF-1 pathway via p53 and p53-related regulators in the skin epidermis. Female SENCAR mice were pair-fed an AIN-93 diet with or without 10-week treadmill exercise at 20 m/min, 60 min/day and 5 days/week. Animals were topically treated with TPA 2 hours before sacrifice and the target proteins in the epidermis were analyzed by both immunohistochemistry and Western blot. Under TPA or vehicle treatment, MDM2 expression was significantly reduced in exercised mice when compared with sedentary control. Meanwhile, p53 was significantly elevated. In addition, p53-transcriptioned proteins, i.e., p21, IGFBP-3, and PTEN, increased in response to exercise. There was a synergy effect between exercise and TPA on the decreased MDM2 and increased p53, but not p53-transcripted proteins. Taken together, exercise appeared to activate p53, resulting in enhanced expression of p21, IGFBP-3, and PTEN that might induce a negative regulation of IGF-1 pathway and thus contribute to the observed cancer prevention by exercise in this skin cancer model.

  15. Inhibition of insulin/IGF-1 receptor signaling protects from mitochondria-mediated kidney failure

    PubMed Central

    Ising, Christina; Koehler, Sybille; Brähler, Sebastian; Merkwirth, Carsten; Höhne, Martin; Baris, Olivier R; Hagmann, Henning; Kann, Martin; Fabretti, Francesca; Dafinger, Claudia; Bloch, Wilhelm; Schermer, Bernhard; Linkermann, Andreas; Brüning, Jens C; Kurschat, Christine E; Müller, Roman-Ulrich; Wiesner, Rudolf J; Langer, Thomas; Benzing, Thomas; Brinkkoetter, Paul Thomas

    2015-01-01

    Mitochondrial dysfunction and alterations in energy metabolism have been implicated in a variety of human diseases. Mitochondrial fusion is essential for maintenance of mitochondrial function and requires the prohibitin ring complex subunit prohibitin-2 (PHB2) at the mitochondrial inner membrane. Here, we provide a link between PHB2 deficiency and hyperactive insulin/IGF-1 signaling. Deletion of PHB2 in podocytes of mice, terminally differentiated cells at the kidney filtration barrier, caused progressive proteinuria, kidney failure, and death of the animals and resulted in hyperphosphorylation of S6 ribosomal protein (S6RP), a known mediator of the mTOR signaling pathway. Inhibition of the insulin/IGF-1 signaling system through genetic deletion of the insulin receptor alone or in combination with the IGF-1 receptor or treatment with rapamycin prevented hyperphosphorylation of S6RP without affecting the mitochondrial structural defect, alleviated renal disease, and delayed the onset of kidney failure in PHB2-deficient animals. Evidently, perturbation of insulin/IGF-1 receptor signaling contributes to tissue damage in mitochondrial disease, which may allow therapeutic intervention against a wide spectrum of diseases. PMID:25643582

  16. Macrophage and adipocyte IGF1 maintain adipose tissue homeostasis during metabolic stresses

    PubMed Central

    Chang, Hye Rim; Kim, Hae Jin; Xu, Xiaoyuan; Ferrante, Anthony W.

    2015-01-01

    Objective IGF1 regulates differentiation and growth of tissues and reduces stress and injury. IGF1 also in a tissue specific manner modulates the differentiation and lipid storage capacity of adipocytes in vitro, but its roles in adipose tissue development and response to stress are not known. Methods To study IGF1 in vivo, we identified the cellular sources of adipose tissue Igf1 expression and generated mice with targeted deletion in adipocytes and macrophages. We studied the effects of adipocyte and macrophage deficiency of IGF1 on adipose tissue development, and the response to a chronic (high fat feeding) and acute (cold challenge) stress. Results The expression of Igf1 by adipose tissue is derived from multiple cell types including adipocytes and macrophages. In lean animals, adipocytes are the primary source of IGF1 but in obesity expression by adipocytes is reduced and by macrophages increased, so as to maintain overall adipose tissue Igf1 expression. Genetic deletion studies reveal that adipocyte-derived IGF1 regulates perigonadal but not subcutaneous adipose tissue mass during high fat feeding and the development of obesity. Conversely, macrophage-derived IGF1 acutely modulates PGAT (PGAT) mass during thermogenic challenges. Conclusions Local IGF1 is not required in lean adipose tissue development but required to maintain homeostasis during both chronic and acute metabolic stresses. PMID:26663512

  17. Osteoblast-Specific Loss of IGF1R Signaling Results in Impaired Endochondral Bone Formation During Fracture Healing.

    PubMed

    Wang, Tao; Wang, Yongmei; Menendez, Alicia; Fong, Chak; Babey, Muriel; Tahimic, Candice G T; Cheng, Zhiqiang; Li, Alfred; Chang, Wenhan; Bikle, Daniel D

    2015-09-01

    Insulin-like growth factors (IGFs) are important local regulators during fracture healing. Although IGF1 deficiency is known to increase the risk of delayed union or non-union fractures in the elderly population, the underlying mechanisms that contribute to this defect remains unclear. In this study, IGF1 signaling during fracture healing was investigated in an osteoblast-specific IGF1 receptor (IGF1R) conditional knockout (KO) mouse model. A closed tibial fracture was induced in IGF1R(flox/flox) /2.3-kb α1(1)-collagen-Cre (KO) and IGF1R(flox/flox) (control) mice aged 12 weeks. Fracture callus samples and nonfractured tibial diaphysis were collected and analyzed by μCT, histology, immunohistochemistry, histomorphometry, and gene expression analysis at 10, 15, 21, and 28 days after fracture. A smaller size callus, lower bone volume accompanied by a defect in mineralization, bone microarchitectural abnormalities, and a higher cartilage volume were observed in the callus of these KO mice. The levels of osteoblast differentiation markers (osteocalcin, alkaline phosphatase, collagen 1α1) were significantly reduced, but the early osteoblast transcription factor runx2, as well as chondrocyte differentiation markers (collagen 2α1 and collagen 10α1) were significantly increased in the KO callus. Moreover, increased numbers of osteoclasts and impaired angiogenesis were observed during the first 15 days of fracture repair, but decreased numbers of osteoclasts were found in the later stages of fracture repair in the KO mice. Although baseline nonfractured tibias of KO mice had decreased trabecular and cortical bone compared to control mice, subsequent studies with mice expressing the 2.3-kb α1(1)-collagen-Cre ERT2 construct and given tamoxifen at the time of fracture and so starting with comparable bone levels showed similar impairment in fracture repair at least initially. Our data indicate that not only is the IGF1R in osteoblasts involved in osteoblast differentiation

  18. Insulin and IGF-1 signalling: longevity, protein homoeostasis and Alzheimer's disease.

    PubMed

    O'Neill, Cora; Kiely, Aoife P; Coakley, Meghan F; Manning, Sean; Long-Smith, Caitriona M

    2012-08-01

    The quality control of protein homoeostasis deteriorates with aging, causing the accumulation of misfolded proteins and neurodegeneration. Thus, in AD (Alzheimer's disease), soluble oligomers, protofibrils and fibrils of the Aβ (amyloid β-peptide) and tau protein accumulate in specific brain regions. This is associated with the progressive destruction of synaptic circuits controlling memory and higher mental function. The primary signalling mechanisms that (i) become defective in AD to alter the normal proteostasis of Aβ and tau, and (ii) initiate a pathophysiological response to cause cognitive decline, are unclear. The IIS [insulin/IGF-1 (insulin-like growth factor 1)-like signalling] pathway is mechanistically linked to longevity, protein homoeostasis, learning and memory, and is emerging to be central to both (i) and (ii). This pathway is aberrantly overactivated in AD brain at the level of increased activation of the serine/threonine kinase Akt and the phosphorylation of its downstream targets, including mTOR (mammalian target of rapamycin). Feedback inhibition of normal insulin/IGF activation of the pathway also occurs in AD due to inactivation of IRS-1 (insulin receptor substrate 1) and decreased IRS-1/2 levels. Pathogenic forms of Aβ may induce aberrant sustained activation of the PI3K (phosphoinositide 3-kinase)/Akt signal in AD, also causing non-responsive insulin and IGF-1 receptor, and altered tau phosphorylation, conformation and function. Reducing IIS activity in animal models by decreasing IGF-1R levels or inhibiting mTOR activity alters Aβ and tau protein homoeostasis towards less toxic protein conformations, improves cognitive function and extends healthy lifespan. Thus normalizing IIS dysfunction may be therapeutically relevant in abrogating Aβ and tau proteotoxicity, synaptic dysfunction and cognitive decline in AD.

  19. Insulin and IGF-1 improve mitochondrial function in a PI-3K/Akt-dependent manner and reduce mitochondrial generation of reactive oxygen species in Huntington's disease knock-in striatal cells.

    PubMed

    Ribeiro, Márcio; Rosenstock, Tatiana R; Oliveira, Ana M; Oliveira, Catarina R; Rego, A Cristina

    2014-09-01

    Oxidative stress and mitochondrial dysfunction have been described in Huntington's disease, a disorder caused by expression of mutant huntingtin (mHtt). IGF-1 was previously shown to protect HD cells, whereas insulin prevented neuronal oxidative stress. In this work we analyzed the role of insulin and IGF-1 in striatal cells derived from HD knock-in mice on mitochondrial production of reactive oxygen species (ROS) and related antioxidant and signaling pathways influencing mitochondrial function. Insulin and IGF-1 decreased mitochondrial ROS induced by mHtt and normalized mitochondrial SOD activity, without affecting intracellular glutathione levels. IGF-1 and insulin promoted Akt phosphorylation without changing the nuclear levels of phosphorylated Nrf2 or Nrf2/ARE activity. Insulin and IGF-1 treatment also decreased mitochondrial Drp1 phosphorylation, suggesting reduced mitochondrial fragmentation, and ameliorated mitochondrial function in HD cells in a PI-3K/Akt-dependent manner. This was accompanied by increased total and phosphorylated Akt, Tfam, and mitochondrial-encoded cytochrome c oxidase II, as well as Tom20 and Tom40 in mitochondria of insulin- and IGF-1-treated mutant striatal cells. Concomitantly, insulin/IGF-1-treated mutant cells showed reduced apoptotic features. Hence, insulin and IGF-1 improve mitochondrial function and reduce mitochondrial ROS caused by mHtt by activating the PI-3K/Akt signaling pathway, in a process independent of Nrf2 transcriptional activity, but involving enhanced mitochondrial levels of Akt and mitochondrial-encoded complex IV subunit.

  20. C. elegans VANG-1 Modulates Life Span via Insulin/IGF-1-Like Signaling

    PubMed Central

    Honnen, Sebastian J.; Büchter, Christian; Schröder, Verena; Hoffmann, Michael; Kohara, Yuji; Kampkötter, Andreas; Bossinger, Olaf

    2012-01-01

    The planar cell polarity (PCP) pathway is highly conserved from Drosophila to humans and a PCP-like pathway has recently been described in the nematode Caenorhabditis elegans. The developmental function of this pathway is to coordinate the orientation of cells or structures within the plane of an epithelium or to organize cell-cell intercalation required for correct morphogenesis. Here, we describe a novel role of VANG-1, the only C. elegans ortholog of the conserved PCP component Strabismus/Van Gogh. We show that two alleles of vang-1 and depletion of the protein by RNAi cause an increase of mean life span up to 40%. Consistent with the longevity phenotype vang-1 animals also show enhanced resistance to thermal- and oxidative stress and decreased lipofuscin accumulation. In addition, vang-1 mutants show defects like reduced brood size, decreased ovulation rate and prolonged reproductive span, which are also related to gerontogenes. The germline, but not the intestine or neurons, seems to be the primary site of vang-1 function. Life span extension in vang-1 mutants depends on the insulin/IGF-1-like receptor DAF-2 and DAF-16/FoxO transcription factor. RNAi against the phase II detoxification transcription factor SKN-1/Nrf2 also reduced vang-1 life span that might be explained by gradual inhibition of insulin/IGF-1-like signaling in vang-1. This is the first time that a key player of the PCP pathway is shown to be involved in the insulin/IGF-1-like signaling dependent modulation of life span in C. elegans. PMID:22359667

  1. Thrombin-activated platelets induce proliferation of human skin fibroblasts by stimulating autocrine production of insulin-like growth factor-1.

    PubMed

    Giacco, Ferdinando; Perruolo, Giuseppe; D'Agostino, Elio; Fratellanza, Giorgio; Perna, Enzo; Misso, Saverio; Saldalamacchia, Gennaro; Oriente, Francesco; Fiory, Francesca; Miele, Claudia; Formisano, Salvatore; Beguinot, Francesco; Formisano, Pietro

    2006-11-01

    Platelet components have found successful clinical utilization to initiate or to accelerate tissue-repair mechanisms. However, the molecular pathways by which platelet factors contribute to tissue regeneration have not been fully elucidated. We have studied the effect of thrombin-activated platelets (TAPs) on cell growth in vivo and in cultured cell systems. Application of TAPs to ulcerative skin lesions of diabetic patients induced local activation of ERK1/2 and Akt/PKB. Moreover, when applied to cultured human skin fibroblasts, TAPs promoted cell growth and DNA synthesis and activated platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF)-1 receptor tyrosine kinases. PDGF was released by TAPs and rapidly achieved a plateau. At variance, the release of IGF-1 was mainly provided by the TAPs-stimulated fibroblasts and progressively increased up to 48 h. The PDGF-R blocker Ag1296 reduced the activation of Akt/PKB and, at a lesser extent, of ERK1/2. Conversely, inhibition of IGF-1 signaling by Ag1024 and expression of a dominant-negative IGF-1R mutant selectively reduced the stimulation of ERK1/2 by TAPs and fibroblast-released factors, with minor changes of Akt/PKB activity. Thus, platelet factors promote fibroblast growth by acutely activating Akt/PKB and ERK1/2. Sustained activation of ERK1/2, however, requires autocrine production of IGF-1 by TAPs-stimulated fibroblasts.

  2. Calorie restriction in humans inhibits the PI3K/AKT pathway and induces a younger transcription profile

    PubMed Central

    Mercken, Evi M.; Crosby, Seth D.; Lamming, Dudley W.; JeBailey, Lellean; Krzysik-Walker, Susan; Villareal, Dennis; Capri, Miriam; Franceschi, Claudio; Zhang, Yongqing; Becker, Kevin; Sabatini, David M.; de Cabo, Rafael; Fontana, Luigi

    2013-01-01

    Summary Caloric restriction (CR) and down-regulation of the insulin/IGF pathway are the most robust interventions known to increase longevity in lower organisms. However, little is known about the molecular adaptations induced by CR in humans. Here we report that long-term CR in humans inhibits the IGF-1/insulin pathway in skeletal muscle, a key metabolic tissue. We also demonstrate that CR-induced dramatic changes of the skeletal muscle transcriptional profile that resemble those of younger individuals. Finally, in both rats and humans CR evoked similar responses in the transcriptional profiles of skeletal muscle. This common signature consisted of three key pathways typically associated with longevity: IGF-1/insulin signaling, mitochondrial biogenesis and inflammation. Furthermore, our data identifies promising pathways for therapeutic targets to combat age-related diseases and promote health in humans. PMID:23601134

  3. R1507, an anti-insulin-like growth factor-1 receptor (IGF-1R) antibody, and EWS/FLI-1 siRNA in Ewing's sarcoma: convergence at the IGF/IGFR/Akt axis.

    PubMed

    Huang, Helen J; Angelo, Laura S; Rodon, Jordi; Sun, Michael; Kuenkele, Klaus-Peter; Parsons, Henrique A; Trent, Jonathan C; Kurzrock, Razelle

    2011-01-01

    A subset of patients with Ewing's sarcoma responds to anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies. Mechanisms of sensitivity and resistance are unknown. We investigated whether an anti-IGF-1R antibody acts via a pathway that could also be suppressed by small interfering (si) RNA against the EWS/FLI-1 fusion protein, the hallmark of Ewing's sarcoma. The growth of two Ewing's sarcoma cell lines (TC-32 and TC-71) was inhibited by the fully human anti-IGF-1R antibody, R1507 (clonogenic and MTT assays). TC-32 and TC-71 cells express high levels of IGF-2, while RD-ES and A4573 Ewing's cell lines, which were less responsive to R1507 in our assays, express low or undetectable IGF-2, respectively. TC-71 cells also expressed high levels of IGF-1R, and R1507 decreased steady-state levels of this receptor by internalization/degradation, an effect which was associated with a decrease in p-IGF-1R, p-IRS-1, and p-Akt. EWS/FLI-1 siRNA also decreased p-Akt, due to its ability to increase IGF-BP3 levels and subsequently decrease IGF-1 and IGF-2 levels, thus inhibiting signaling through p-IGF-1R. This inhibition correlated with growth suppression and apoptosis. The attenuation of Akt activation was confirmed in TC-71 and HEK-293 (human embryonic kidney) cells by transfecting them with IGF-1R siRNA. We conclude that antibodies and siRNA to IGF-1R, as well as siRNA to EWS/FLI-1, act via intersecting IGF/IGF-1R signals that suppress a common point in this pathway, namely the phosphorylation of Akt.

  4. The effect of forced expression of mutated K-RAS gene on gastrointestinal cancer cell lines and the IGF-1R targeting therapy.

    PubMed

    Matsunaga, Yasutaka; Adachi, Yasushi; Sasaki, Yasushi; Koide, Hideyuki; Motoya, Masayo; Nosho, Katsuhiko; Takagi, Hideyasu; Yamamoto, Hiroyuki; Sasaki, Shigeru; Arimura, Yoshiaki; Tokino, Takashi; Carbone, David P; Imai, Kohzoh; Shinomura, Yasuhisa

    2017-02-01

    Mutation in K-RAS (K-RAS-MT) plays important roles in both cancer progression and resistance to anti-epidermal growth factor receptor (EGFR) therapy in gastrointestinal tumors. Insulin-like growth factor-1 receptor (IGF-1R) signaling is required for carcinogenicity and progression of many tumors as well. We have previously shown successful therapy for gastrointestinal cancer cell lines bearing a K-RAS mutation using an anti-IGF-1R monoclonal antibody. In this study, we sought to evaluate effects of forced K-RAS-MT expression on gastrointestinal cancer cell lines representing a possible second resistance mechanism for anti-EGFR therapy and IGF-1R-targeted therapy for these transfectants. We made stable transfectants of K-RAS-MT in two gastrointestinal cancer cell lines, colorectal RKO and pancreatic BxPC-3. We assessed the effect of forced expression of K-RAS-MT on proliferation, apoptosis, migration, and invasion in gastrointestinal cancer cells. Then we assessed anti-tumor effects of dominant negative IGF-1R (IGF-1R/dn) and an IGF-1R inhibitor, picropodophyllin, on the K-RAS-MT transfectants. Overexpression of K-RAS-MT in gastrointestinal cancer cell lines led to more aggressive phenotypes, with increased proliferation, decreased apoptosis, and increased motility and invasion. IGF-1R blockade suppressed cell growth, colony formation, migration, and invasion, and up-regulated chemotherapy-induced apoptosis of gastrointestinal cancer cells, even when K-RAS-MT was over-expressed. IGF-1R blockade inhibited the Akt pathway more than the extracellular signal-regulated kinase (ERK) pathway in the K-RAS-MT transfectants. IGF-1R/dn, moreover, inhibited the growth of murine xenografts expressing K-RAS-MT. Thus, K-RAS-MT might be important for progressive phonotype observed in gastrointestinal cancers. IGF-1R decoy is a candidate molecular therapeutic approach for gastrointestinal cancers even if K-RAS is mutated. © 2016 Wiley Periodicals, Inc.

  5. Protracted upregulation of leptin and IGF1 is associated with activation of PI3K/Akt and JAK2 pathway in mouse intestine after ionizing radiation exposure.

    PubMed

    Suman, Shubhankar; Kallakury, Bhaskar V S; Fornace, Albert J; Datta, Kamal

    2015-01-01

    Ionizing radiation is a known risk factor for gastrointestinal (GI) pathologies including cancer. Hormones and related signaling crosstalk, which could contribute to radiation-induced persistent pathophysiologic changes in the small intestine and colon, remain to be explored. The current study assessed perturbation of GI homeostasis-related hormones and signaling pathways at the systemic as well as at the tissue level in small intestine and colon. Mice (6-8 week old C57BL/6J) were exposed to 2 Gy γ radiation, serum and tissue samples were collected, and insulin like growth factor 1 (IGF-1) and leptin signaling were assessed two or twelve months after radiation exposure. Serum levels of IGF-1, IGF binding protein 3 (IGFBP3), leptin, and adiponectin were altered at these times after irradiation. Radiation was associated with increased IGF1 receptor (IGF1R) and obesity (leptin) receptor (Ob-R), decreased adiponectin receptor 1 (Adipo-R1) and 2 (Adipo-R2), and increased Ki-67 levels in small intestine and colon at both time points. Immunoblot analysis further showed increased IGF1R and Ob-R, and decreased Adipo-R2. Additionally, upregulation of PI3K/Akt and JAK2 signaling, which are downstream of IGF1 and leptin, was also observed in irradiated samples at both time points. These results when considered along with increased cell proliferation in the small intestine and colon demonstrate for the first time that ionizing radiation can persistently increase IGF1 and leptin and activate downstream proliferative pathways, which may contribute to GI functional alterations and carcinogenesis.

  6. Nucleus pulposus cells derived IGF-1 and MCP-1 enhance osteoclastogenesis and vertebrae disruption in lumbar disc herniation

    PubMed Central

    Zhu, Zhongjiao; Huang, Peng; Chong, Yanxue; George, Suraj K; Wen, Bingtao; Han, Na; Liu, Zhiqiang; Kang, Lixin; Lin, Nie

    2014-01-01

    Study design: Chronic strained lumbar disc herniation (LDH) cases were classified into bulging LDH, herniated LDH and prolapse LDH types according to imaging examination, and vertebrae disruptions were evaluated. Cytokines derived from the nucleus pulposus cells were detected, and their effects on osteoclastogenesis, as well as the mechanisms involved, were studied via an in vitro osteoclast differentiation system. Objective: To clarify the mechanisms of lumbar vertebrae resorption induced by lumbar herniation. Summary and background data: Chronic strained lumbar disc herniation induced vertebrae erosion exacerbates quality of patients’ life and clinical outcome. Although nucleus pulposus cells derived cytokines were reported to play an important role in this pathogenesis, the fundamental mechanisms underlying this process are still unclear. Methods: Chronic strained lumbar disc herniation patients were diagnosed with CT scan and T2-weighted magnetic resonance imaging. RNA was extracted from 192 surgical specimens of the herniated lumbar disc and 29 surgical excisions of the lumbar disc from spinal injury patients. The expressions of osteoclastogenesis related cytokines and chemokines were examined using real time PCR. Monocytes were induced into osteoclast with M-CSF and RANKL in vitro, while the IGF-1 and MCP-1 were added into the differentiation procedure in order to evaluate the effects and explore the molecular mechanisms. Results: Vertebrae erosion had a positive relationship with lumbar disc herniation severity types. In all of the osteoclastogenesis related cytokines, the IGF-1 and MCP-1 were the most highly expressed in the nucleus pulposus cells. IGF-1 enhances activation of NF-kB signaling directly, but MCP-1 upregulated the expression of RANK, so that enhanced cellular sensitivity to RANKL resulted in increasing osteoclastogenesis and activity. Conclusion: Lumbar herniation induced overexpression of IGF-1 and MCP-1 in nucleus pulposus cells aggravated

  7. Diagnosis of endocrine disease: limitations of the IGF1 generation test in children with short stature.

    PubMed

    Coutant, Régis; Dörr, Helmuth-Günther; Gleeson, Helena; Argente, Jesús

    2012-03-01

    The IGF1 generation test (IGFGT) is often used during the assessment of suspected GH insensitivity (GHI). We report the results of a survey undertaken in 2010 to determine the use of IGFGT amongst members of the European Society for Paediatric Endocrinology to evaluate suspected GHI. The literature surrounding the usefulness and limitations of IGFGT are reviewed, and recommendations provided for its use. Of 112 paediatric endocrinologists from 30 countries who responded to the survey, 91 (81%) reported that they had used the IGFGT in the previous 2 years; >10 IGFGT protocols were used. The IGFGT impacted treatment decisions for 97% of the respondents and was a prerequisite for recombinant human IGF1 treatment for 45% of respondents. From a literature review, sensitivity of the IGFGT was evaluated as 77-91% in molecularly proven cases of GHI; specificity was ≤97%, depending on the protocol. The positive predictive value of the IGFGT is likely to be low, as the frequency of normality is predictably higher than that of abnormality in GH signalling. Given the limitations of the IGFGT in the most severe cases of GHI syndrome (GHIS), the ability of the IGFGT to detect less severe GHIS is doubtful. In a pragmatic approach, the IGFGT may not be useful for the diagnosis of GHIS.

  8. Phosphorylation and IGF-1-mediated dephosphorylation pathways control the activity and the pharmacological properties of skeletal muscle chloride channels

    PubMed Central

    De Luca, Annamaria; Pierno, Sabata; Liantonio, Antonella; Camerino, Claudia; Conte Camerino, Diana

    1998-01-01

    In the present study we tested the hypothesis that insulin-like growth factor-1 (IGF-1) modulates resting chloride conductance (GCl) of rat skeletal muscle by activating a phosphatase and that the chloride channel, based on the activity of phosphorylating-dephosphorylating pathways, has different sensitivity to specific ligands, such as the enantiomers of 2-(p-chlorophenoxy) propionic acid (CPP).For this purpose GCl in EDL muscle isolated from adult rat was first lowered by treatment with 5 nM 4-β-phorbol 12,13 dibutyrate (4-β-PDB), presumably activating protein kinase C (PKC). The effects of IGF-1 and of the enantiomers of CPP on GCl were then tested.IGF-1 (3.3 nM) had no effect of GCl on EDL muscle fibres in normal physiological solution, whereas it completely counteracted the 30% decrease of GCl induced by 4-β-PDB. No effects of IGF-1 were observed on GCl lowered by the phosphatase inhibitor okadaic acid (0.25 μM).Ceramide, reported to activate on okadaic acid-sensitive phosphatase, mimicked the effects of IGF-1. In fact, N-acetyl-sphingosine (2.5–5 μM), not very effective in control conditions, increased the GCl lowered by the phorbol ester, but not the GCl lowered by okadaic acid.In the presence of 4-β-PDB, GCl was differently affected by the enantiomers of CPP. The S(−)-CPP was remarkably less potent in producing the concentration-dependent reduction of GCl, whereas the R(+)-CPP caused an increase of GCl at all the concentrations tested.In conclusion, the PKC-induced lowering of GCl is counteracted by IGF-1 through an okadaic acid sensitive phosphatase, and this effect can have therapeutic relevance in situations characterized by excessive channel phosphorylation. In turn the phosphorylation state of the channel can modulate the effects and the therapeutic potential of direct channel ligands. PMID:9806330

  9. Effect of locally delivered IGF-1 on nerve regeneration during aging: an experimental study in rats.

    PubMed

    Apel, Peter J; Ma, Jianjun; Callahan, Michael; Northam, Casey N; Alton, Timothy B; Sonntag, William E; Li, Zhongyu

    2010-03-01

    Age is an important predictor of neuromuscular recovery after peripheral nerve injury. Insulin-like growth factor 1 (IGF-1) is a potent neurotrophic factor that is known to decline with increasing age. The purpose of this study was to determine if locally delivered IGF-1 would improve nerve regeneration and neuromuscular recovery in aged animals. Young and aged rats underwent nerve transection and repair with either saline or IGF-1 continuously delivered to the site of the nerve repair. After 3 months, nerve regeneration and neuromuscular junction morphology were assessed. In both young and aged animals, IGF-1 significantly improved axon number, diameter, and density. IGF-1 also significantly increased myelination and Schwann cell activity and preserved the morphology of the postsynaptic neuromuscular junction (NMJ). These results show that aged regenerating nerve is sensitive to IGF-1 treatment.

  10. Hyperosmotic stress-dependent NFkappaB activation is regulated by reactive oxygen species and IGF-1 in cultured cardiomyocytes.

    PubMed

    Eisner, Verónica; Criollo, Alfredo; Quiroga, Clara; Olea-Azar, Claudio; Santibañez, Juan Francisco; Troncoso, Rodrigo; Chiong, Mario; Díaz-Araya, Guillermo; Foncea, Rocío; Lavandero, Sergio

    2006-08-07

    We have recently shown that hyperosmotic stress activates p65/RelB NFkappaB in cultured cardiomyocytes with dichotomic actions on caspase activation and cell death. It remains unexplored how NFkappaB is regulated in cultured rat cardiomyocytes exposed to hyperosmotic stress. We study here: (a) if hyperosmotic stress triggers reactive oxygen species (ROS) generation and in turn whether they regulate NFkappaB and (b) if insulin-like growth factor-1 (IGF-1) modulates ROS production and NFkappaB activation in hyperosmotically-stressed cardiomyocytes. The results showed that hyperosmotic stress generated ROS in cultured cardiac myocytes, in particular the hydroxyl and superoxide species, which were inhibited by N-acetylcysteine (NAC). Hyperosmotic stress-induced NFkappaB activation as determined by IkappaBalpha degradation and NFkappaB DNA binding. NFkappaB activation and procaspase-3 and -9 fragmentation were prevented by NAC and IGF-1. However, this growth factor did not decrease ROS generation induced by hyperosmotic stress, suggesting that its actions over NFkappaB and caspase activation may be due to modulation of events downstream of ROS generation. We conclude that hyperosmotic stress induces ROS, which in turn activates NFkappaB and caspases. IGF-1 prevents NFkappaB activation by a ROS-independent mechanism.

  11. IGF-1R and ErbB3/HER3 contribute to enhanced proliferation and carcinogenesis in trastuzumab-resistant ovarian cancer model

    SciTech Connect

    Jia, Yanhan; Zhang, Yan; Qiao, Chunxia; Liu, Guijun; Zhao, Qing; Zhou, Tingting; Chen, Guojiang; Li, Yali; Feng, Jiannan; Li, Yan; Zhang, Qiuping; Peng, Hui

    2013-07-12

    Highlights: •We established trastuzumab-resistant cell line SKOV3/T. •SKOV3/T enhances proliferation and in vivo carcinogenesis. •IGF-1R and HER3 genes were up-regulated in SKOV3/T based on microarray analysis. •Targeting IGF-1R and/or HER3 inhibited the proliferation of SKOV3/T. •Therapies targeting IGF-1R and HER3 might be effective in ovarian cancer. -- Abstract: Trastuzumab (Herceptin®) has demonstrated clinical potential in several types of HER2-overexpressing human cancers. However, primary and acquired resistance occurs in many HER2-positive patients with regimens. To investigate the possible mechanism of acquired therapeutic resistance to trastuzumab, we have developed a preclinical model of human ovarian cancer cells, SKOV3/T, with the distinctive feature of stronger carcinogenesis. The differences in gene expression between parental and the resistant cells were explored by microarray analysis, of which IGF-1R and HER3 were detected to be key molecules in action. Their correctness was validated by follow-up experiments of RT-PCR, shRNA-mediated knockdown, downstream signal activation, cell cycle distribution and survival. These results suggest that IGF-1R and HER3 differentially regulate trastuzumab resistance and could be promising targets for trastuzumab therapy in ovarian cancer.

  12. Estimated Prestroke Peak VO2 Is Related to Circulating IGF-1 Levels During Acute Stroke.

    PubMed

    Mattlage, Anna E; Rippee, Michael A; Abraham, Michael G; Sandt, Janice; Billinger, Sandra A

    2017-01-01

    Background Insulin-like growth factor-1 (IGF-1) is neuroprotective after stroke and is regulated by insulin-like binding protein-3 (IGFBP-3). In healthy individuals, exercise and improved aerobic fitness (peak oxygen uptake; peak VO2) increases IGF-1 in circulation. Understanding the relationship between estimated prestroke aerobic fitness and IGF-1 and IGFBP-3 after stroke may provide insight into the benefits of exercise and aerobic fitness on stroke recovery. Objective The purpose of this study was to determine the relationship of IGF-1 and IGFBP-3 to estimated prestroke peak VO2 in individuals with acute stroke. We hypothesized that (1) estimated prestroke peak VO2 would be related to IGF-1 and IGFBP-3 and (2) individuals with higher than median IGF-1 levels will have higher estimated prestroke peak VO2 compared to those with lower than median levels. Methods Fifteen individuals with acute stroke had blood sampled within 72 hours of hospital admission. Prestroke peak VO2 was estimated using a nonexercise prediction equation. IGF-1 and IGFBP-3 levels were quantified using enzyme-linked immunoassay. Results Estimated prestroke peak VO2 was significantly related to circulating IGF-1 levels (r = .60; P = .02) but not IGFBP-3. Individuals with higher than median IGF-1 (117.9 ng/mL) had significantly better estimated aerobic fitness (32.4 ± 6.9 mL kg(-1) min(-1)) than those with lower than median IGF-1 (20.7 ± 7.8 mL kg(-1) min(-1); P = .03). Conclusions Improving aerobic fitness prior to stroke may be beneficial by increasing baseline IGF-1 levels. These results set the groundwork for future clinical trials to determine whether high IGF-1 and aerobic fitness are beneficial to stroke recovery by providing neuroprotection and improving function.

  13. EXPRESSION OF IGF1R IN NORMAL BREAST TISSUE AND SUBSEQUENT RISK OF BREAST CANCER

    PubMed Central

    Tamimi, Rulla M.; Colditz, Graham A.; Wang, Yihong; Collins, Laura C.; Hu, Rong; Rosner, Bernard; Irie, Hanna Y.; Connolly, James L.; Schnitt, Stuart J.

    2011-01-01

    Introduction The growth hormone and insulin-like growth factor (IGF) axis plays an essential role in the growth and development of the mammary gland. IGF1 and IGF1 receptor (IGF1R) may also play a role in the early transformation of mammary cells. Methods Using a nested case-control design, we examined the association between IGF1R expression in normal breast tissue from benign biopsies and subsequent risk of breast cancer within the Nurses’ Health Study. We constructed tissue microarrays (TMAs) containing normal terminal ductal lobular units (TDLUs) from benign breast biopsies. Immunostains for IGF1R were performed on sections cut from the TMAs. A total of 312 women had evaluable IGF1R staining in normal TDLUs; 75 subsequently developed breast cancer (cases) and 237 did not (controls). The epithelial cells in the normal TDLUs were scored for both cytoplasmic and membrane staining for IGF1R. Results Cytoplasmic IGF1R expression was positively associated with subsequent risk of breast cancer (OR=2.47, 95% CI 1.41–4.33). Women whose TDLU epithelial cells showed little or no membrane expression of IGF1R but high levels of cytoplasmic IGF1R were at the highest breast cancer risk and were 15 times more likely to develop subsequent breast cancer when compared with women who had little or no membrane or cytoplasmic IGF1R expression in their TDLU epithelial cells (OR=15.9, 95% CI 3.6–69.8). Conclusion In this study, IGF1R expression patterns in epithelial cells of normal TDLUs in benign breast biopsies were associated with an increased risk of subsequent breast cancer. Additional studies to confirm these findings are necessary. PMID:21197570

  14. Possible contribution of IGF-1 to depressive disorder.

    PubMed

    Szczęsny, Ewa; Slusarczyk, Joanna; Głombik, Katarzyna; Budziszewska, Bogusława; Kubera, Marta; Lasoń, Władysław; Basta-Kaim, Agnieszka

    2013-01-01

    Depression is an illness of unknown origin and involves the dysregulation of many physiological processes disturbed in this disease. It has been postulated that the pathomechanism of depression is complex, and apart from changes in neurotransmitters, a dysregulation of the immune and endocrine systems also plays an important role in the development of this disorder. Recent studies indicate that an impairment of synaptic plasticity in specific areas of the central nervous system (CNS), particularly the hippocampus, may be an important factor in the pathogenesis of depression. The abnormal neural plasticity may be related to alterations in the levels of neurotrophic factors. On this basis, a theory connecting the occurrence of depression with disturbances in neurotrophic factors has gained great attention. This review summarizes data suggesting a role for the neurotrophic factors - especially insulin-like-growth factor-1 (IGF-1) - as possible targets for therapy in depression in the context of depressive behavior modulation, anti-inflammatory action and neuroprotection.

  15. Hyperplasia and cellularity changes in IGF-1-overexpressing skeletal muscle of crucian carp.

    PubMed

    Li, Dongliang; Lou, Qiyong; Zhai, Gang; Peng, Xuyan; Cheng, Xiaoxia; Dai, Xiangyan; Zhuo, Zijian; Shang, Guohui; Jin, Xia; Chen, Xiaowen; Han, Dong; He, Jiangyan; Yin, Zhan

    2014-06-01

    The zebrafish skeletal muscle-specific promoter mylz2 was used to cause crucian carp overexpression of the zebrafish IGF-1 cDNA. In stable transgenic germline F1 progenies, a 5-fold increase in the level of IGF-1 in skeletal muscle was observed. Evident skeletal muscle hyperplasia was observed in the transgenic fish through histologic analysis. By analyzing the RNA sequencing transcriptome of the skeletal muscle of IGF-1 transgenic fish and nontransgenic control fish at 15 months of age, 10 966 transcripts with significant expression levels were identified with definite gene descriptions based on the corresponding zebrafish genome information. Based on the results of our RNA sequencing transcriptome profiling analysis and the results of the real-time quantitative PCR analysis performed to confirm the skeletal muscle transcriptomics analysis, several pathways, including IGF-1 signaling, aerobic metabolism, and protein degradation, were found to be activated in the IGF-1-overexpressing transgenic fish. Intriguingly, our transcriptional expression and protein assays indicated that the overexpression of IGF-1 stimulated a significant shift in the myofiber type toward a more oxidative slow muscle type. Although the body weight was surprisingly decreased by IGF-1 transgenic expression, significantly higher oxygen consumption rates were measured in IGF-1-overexpressing transgenic fish compared with their nontransgenic control fish. These results indicate that the sustained overexpression of IGF-1 in crucian carp skeletal muscle promotes myofiber hyperplasia and cellularity changes, which elicit alterations in the body energy metabolism and skeletal muscle growth.

  16. Elevated blood pressure and enhanced myocardial contractility in mice with severe IGF-1 deficiency.

    PubMed Central

    Lembo, G; Rockman, H A; Hunter, J J; Steinmetz, H; Koch, W J; Ma, L; Prinz, M P; Ross, J; Chien, K R; Powell-Braxton, L

    1996-01-01

    To circumvent the embryonic lethality of a complete deficiency in insulin-like growth factor 1 (IGF-1), we generated mice homozygous for a site-specific insertional event that created a mutant IGF-1 allele (igf1m). These mice have IGF-1 levels 30% of wild type yet survive to adulthood, thereby allowing physiological analysis of the phenotype. Miniaturized catheterization technology revealed elevated conscious blood pressure in IGF-1(m/m) mice, and measurements of left ventricular contractility were increased. Adenylyl cyclase activity was enhanced in IGF-1(m/m) hearts, without an increase in beta-adrenergic receptor density, suggesting that crosstalk between IGF-1 and beta-adrenergic signaling pathways may mediate the increased contractility. The hypertrophic response of the left ventricular myocardium in response to aortic constriction, however, was preserved in IGF-1(m/m) mice. We conclude that chronic alterations in IGF-1 levels can selectively modulate blood pressure and left ventricular function, while not affecting adaptive myocardial hypertrophy in vivo. PMID:8958230

  17. miR-71b regulation of insulin/IGF-1 signaling during starvation in planarians.

    PubMed

    Wu, Y Y; Zhao, J M; Liu, Q; Guo, Q; Liu, Z; Wang, X X; Wang, C Y; Li, R Y; Zhang, Y Z; Zhang, S T

    2015-10-05

    Planarians, which have a large population of stem cells called neoblasts, are molecularly tractable model systems used in the study of regeneration. However, planarians have strong resistance to hunger and have developed growth arrest strategies. For example, they can change their size and undergo growth regression during starvation periods. The results of the current study show that the microRNA, miR-71b, and the insulin/IGF-1 signaling pathway have important functions in the development of starvation-induced planarians. We demonstrate tissue-specific expression of miR-71b using in situ hybridization. By employing real-time polymerase chain reaction, we provide evidence that miR-71b is upregulated in starvation-induced planarians. Furthermore, we validate and verify the target genes of miR-71b.

  18. Combination of IGF-1 gene manipulation and 5-AZA treatment promotes differentiation of mesenchymal stem cells into cardiomyocyte-like cells

    PubMed Central

    LI, JUN; ZHU, KAI; WANG, YULIN; ZHENG, JIAYU; GUO, CHANGFA; LAI, HAO; WANG, CHUNSHENG

    2015-01-01

    Mesenchymal stem cell (MSC) transplantation has been proposed as a promising therapeutic strategy for ischemic myocardium repair following myocardial infarction. Differentiation of MSCs into cardiomyocyte-like cells prior to cell transplantation is advantageous in improving their potential clinical benefits for cardiac repair. In the present study, we isolated and cultured porcine MSCs and evaluated the synergistic effect of 5-azacytidine (5-AZA) treatment and insulin-like growth factor-1 (IGF-1) gene manipulation on MSC differentiation into cardiomyocyte-like cells. Our results demonstrated that 5-AZA treatment alone induced a limited cardiomyocyte-like differentiation effect in vitro. Overexpression of the IGF-1 gene in MSCs improved the induction effect of 5-AZA, while knockdown of the IGF-1 gene attenuated the differentiation. These results suggest that IGF-1 is a significant stimulus affecting the cardiomyocyte-like differentiation of porcine MSCs. In addition, the combination of IGF-1 gene manipulation and 5-AZA treatment provides a new strategy to obtain more committed differentiated cardiomyocyte-like cells from porcine MSCs prior to cell transplantation. PMID:25351395

  19. Model for the complex between the insulin-like growth factor I and its receptor: towards designing antagonists for the IGF-1 receptor.

    PubMed

    Epa, V Chandana; Ward, Colin W

    2006-08-01

    The type-1 insulin-like growth factor receptor (IGF-1R) is the cognate tyrosine kinase receptor for the insulin-like growth factor IGF-I and is expressed widely in many foetal and postnatal tissue cells. IGF-1R is overexpressed in a number of human tumour types and is a valid target for anti-cancer therapeutic efforts. Designing antagonists for IGF-1R would be greatly facilitated by the availability of structural information on the complex between IGF-I and IGF-1R. In the present work we model the three-dimensional structure of the complex between IGF-I and the first three domains of IGF-1R using a macromolecular docking method guided by selected experimental data. Interface metrics indicative of the binding affinity and reliability of the model are computed and compared with other biomolecular complexes. This model is consistent with experimental chimerical and mutagenesis data, provides a structural basis for understanding the primary interaction of IGF-I with its receptor and facilitates design of antagonist ligands.

  20. A phosphatase-independent gain-of-function mutation in PTEN triggers aberrant cell growth in astrocytes through an autocrine IGF-1 loop.

    PubMed

    Fernández, S; Genis, L; Torres-Alemán, I

    2014-08-07

    Loss-of-function mutations in the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome10) contribute to aberrant cell growth in part through upregulation of the mitogenic IGF-1/PI3K/Akt pathway. In turn, this pathway exerts a homeostatic feedback over PTEN. Using mutagenesis analysis to explore a possible impact of this mutual control on astrocyte growth, we found that truncation of the C-terminal region of PTEN (Δ51) associates with a marked increase in NFκB activity, a transcription factor overactivated in astrocyte tumors. Whereas mutations of PTEN are considered to lead to a loss-of-function, PTENΔ51, a truncation that comprises a region frequently mutated in human gliomas, displayed a neomorphic (gain-of-function) activity that was independent of its phosphatase activity. This gain-of-function of PTENΔ51 includes stimulation of IGF-1 synthesis through protein kinase A activation of the IGF-1 promoter. Increased IGF-1 originates an autocrine loop that activates Akt and NFκB. Constitutive activation of NFκB in PTENΔ51-expressing astrocytes leads to aberrant cell growth; astrocytes expressing this mutant PTEN generate colonies in vitro and tumors in vivo. Mutations converting a tumor suppressor such as PTEN into a tumor promoter through a gain-of-function involving IGF-1 production may further our understanding of the role played by this growth factor in glioma growth and help us define druggable targets for personalized therapy.

  1. Dietary and pharmacological modification of the insulin/IGF-1 system: exploiting the full repertoire against cancer

    PubMed Central

    Klement, R J; Fink, M K

    2016-01-01

    As more and more links between cancer and metabolism are discovered, new approaches to treat cancer using these mechanisms are considered. Dietary restriction of either calories or macronutrients has shown great potential in animal studies to both reduce the incidence and growth of cancer, and to act synergistically with other treatment strategies. These studies have also shown that dietary restriction simultaneously targets many of the molecular pathways that are targeted individually by anticancer drugs. The insulin/insulin-like growth factor-1 (IGF-1) system has thereby emerged as a key regulator of cancer growth pathways. Although lowering of insulin levels with diet or drugs such as metformin and diazoxide seems generally beneficial, some practitioners also utilize strategic elevations of insulin levels in combination with chemotherapeutic drugs. This indicates a broad spectrum of possibilities for modulating the insulin/IGF-1 system in cancer treatment. With a specific focus on dietary restriction, insulin administration and the insulin-lowering drug diazoxide, such modifications of the insulin/IGF-1 system are the topic of this review. Although preclinical data are promising, we point out that insulin regulation and the metabolic response to a certain diet often differ between mice and humans. Thus, the need for collecting more human data has to be emphasized. PMID:26878387

  2. Differential regulation of igf1 and igf1r mRNA levels in the two hepatic lobes following intrauterine growth restriction and its treatment with intra-amniotic insulin-like growth factor-1 in ovine fetuses.

    PubMed

    Darp, Revati A; de Boo, Hendrina A; Phua, Hui Hui; Oliver, Mark H; Derraik, José G B; Harding, Jane E; Bloomfield, Frank H

    2010-01-01

    Intrauterine growth restriction (IUGR) has life-long health implications, yet there is no effective prenatal treatment. Daily intra-amniotic administration of insulin-like growth factor (IGF)-1 to IUGR fetal sheep improves fetal gut maturation but suppresses hepatic igf1 gene expression. Fetal hepatic blood supply is regulated, in part, by shunting of oxygen- and nutrient-rich umbilical venous blood through the ductus venosus, with the left hepatic lobe predominantly supplied by umbilical venous blood and the right hepatic lobe predominantly supplied by the portal circulation. We hypothesised that: (1) once-weekly intra-amniotic IGF-1 treatment of IUGR would be effective in promoting gut maturation; and (2) IUGR and its treatment with intra-amniotic IGF-1 would differentially affect igf1 and igf1r mRNA expression in the two hepatic lobes. IUGR fetuses received 360 µg IGF-1 or saline intra-amniotically once weekly from 110 until 131 days gestation. Treatment of IUGR fetuses with IGF-1 reversed impaired gut growth. In unembolised, untreated control fetuses, igf1 mRNA levels were 19% lower in the right hepatic lobe than in the left; in IUGR fetuses, igf1 and igf1r mRNA levels were sixfold higher in the right lobe. IGF-1 treatment reduced igf1 and igf1r mRNA levels in both lobes compared with IUGR fetuses. Thus, weekly intra-amniotic IGF-1 treatment, a clinically feasible approach, reverses the impaired gut development seen in IUGR. Furthermore, igf1 and igf1r mRNA levels are differentially expressed in the two hepatic lobes and relative expression in the two lobes is altered by both IUGR and intra-amniotic IGF-1 treatment.

  3. Insulin and IGF-1 receptors regulate FoxO-mediated signaling in muscle proteostasis

    PubMed Central

    O’Neill, Brian T.; Lee, Kevin Y.; Klaus, Katherine; Softic, Samir; Krumpoch, Megan T.; Stanford, Kristin I.; Robinson, Matthew M.; Cai, Weikang; Kleinridders, Andre; Pereira, Renata O.; Hirshman, Michael F.; Accili, Domenico; Goodyear, Laurie J.; Nair, K. Sreekumaran

    2016-01-01

    Diabetes strongly impacts protein metabolism, particularly in skeletal muscle. Insulin and IGF-1 enhance muscle protein synthesis through their receptors, but the relative roles of each in muscle proteostasis have not been fully elucidated. Using mice with muscle-specific deletion of the insulin receptor (M-IR–/– mice), the IGF-1 receptor (M-IGF1R–/– mice), or both (MIGIRKO mice), we assessed the relative contributions of IR and IGF1R signaling to muscle proteostasis. In differentiated muscle, IR expression predominated over IGF1R expression, and correspondingly, M-IR–/– mice displayed a moderate reduction in muscle mass whereas M-IGF1R–/– mice did not. However, these receptors serve complementary roles, such that double-knockout MIGIRKO mice displayed a marked reduction in muscle mass that was linked to increases in proteasomal and autophagy-lysosomal degradation, accompanied by a high-protein-turnover state. Combined muscle-specific deletion of FoxO1, FoxO3, and FoxO4 in MIGIRKO mice reversed increased autophagy and completely rescued muscle mass without changing proteasomal activity. These data indicate that signaling via IR is more important than IGF1R in controlling proteostasis in differentiated muscle. Nonetheless, the overlap of IR and IGF1R signaling is critical to the regulation of muscle protein turnover, and this regulation depends on suppression of FoxO-regulated, autophagy-mediated protein degradation. PMID:27525440

  4. IGF-1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging.

    PubMed

    Toth, Peter; Tarantini, Stefano; Ashpole, Nicole M; Tucsek, Zsuzsanna; Milne, Ginger L; Valcarcel-Ares, Noa M; Menyhart, Akos; Farkas, Eszter; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2015-12-01

    Aging is associated with marked deficiency in circulating IGF-1, which has been shown to contribute to age-related cognitive decline. Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age-related cognitive impairment. To establish the link between IGF-1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF-1 deficiency (Igf1(f/f) -TBG-Cre-AAV8) and accelerated vascular aging. We found that IGF-1-deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal-dependent spatial memory test, mimicking the aging phenotype. IGF-1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF-1 deficiency also impaired glutamate-mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF-1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment.

  5. The relationships among IGF-1, DNA content, and protein accumulation during skeletal muscle hypertrophy

    NASA Technical Reports Server (NTRS)

    Adams, G. R.; Haddad, F.

    1996-01-01

    Insulin-like growth factor-1 (IGF-1) is known to have anabolic effects on skeletal muscle cells. This study examined the time course of muscle hypertrophy and associated IGF-1 peptide and mRNA expression. Data were collected at 3, 7, 14, and 28 days after surgical removal of synergistic muscles of both normal and hypophysectomized (HX) animals. Overloading increased the plantaris (Plant) mass, myofiber size, and protein-to-body weight ratio in both groups (normal and HX; P < 0.05). Muscle IGF-1 peptide levels peaked at 3 (normal) and 7 (HX) days of overloading with maximum 4.1-fold (normal) and 6.2-fold (HX) increases. Increases in muscle IGF-1 preceded the hypertrophic response. Total DNA content of the overloaded Plant increased in both groups. There was a strong positive relationship between IGF-1 peptide and DNA content in the overloaded Plant from both groups. These results indicate that 1) the muscles from rats with both normal and severely depressed systemic levels of IGF-1 respond to functional overload with an increase in local IGF-1 expression and 2) this elevated IGF-1 may be contributing to the hypertrophy response, possibly via the mobilization of satellite cells to provide increases in muscle DNA.

  6. Spuriously Elevated Serum IGF-1 in Adult Individuals with Delayed Puberty: A Diagnostic Pitfall.

    PubMed

    Imran, Syed Ali; Pelkey, Michael; Clarke, David B; Clayton, Dale; Trainer, Peter; Ezzat, Shereen

    2010-01-01

    Serum insulin-like growth factor-1 (IGF-1) is a sensitive marker of growth hormone (GH) activity. The levels of IGF-1 vary widely, peaking during puberty and declining with advancing age. During adolescence, serum IGF-1 levels tend to correlate better with pubertal stage rather than chronological age. Here we discuss two cases of delayed puberty, both in their 20s, who presented with high serum IGF-1 but no clinical or biochemical evidence of hypersomatotropism as confirmed by appropriate GH response to an oral glucose challenge. Both individuals achieved full pubertal status with testosterone replacement therapy and their serum IGF-1 levels settled into normal age-specific range. We suggest that in chronologically adult individuals with delayed puberty, serum IGF-1 should not be interpreted on the basis of age-specific normal values but rather on their pubertal status. Furthermore, in the absence of another cause of elevated IGF-1, the expectation is that IGF-1 levels will decline towards age-normative ranges following androgen replacement therapy.

  7. IGF-1 and Chondroitinase ABC Augment Nerve Regeneration after Vascularized Composite Limb Allotransplantation

    PubMed Central

    Kostereva, Nataliya V.; Wang, Yong; Fletcher, Derek R.; Unadkat, Jignesh V.; Schnider, Jonas T.; Komatsu, Chiaki; Yang, Yang; Stolz, Donna B.; Davis, Michael R.; Plock, Jan A.; Gorantla, Vijay S.

    2016-01-01

    Impaired nerve regeneration and inadequate recovery of motor and sensory function following peripheral nerve repair remain the most significant hurdles to optimal functional and quality of life outcomes in vascularized tissue allotransplantation (VCA). Neurotherapeutics such as Insulin-like Growth Factor-1 (IGF-1) and chondroitinase ABC (CH) have shown promise in augmenting or accelerating nerve regeneration in experimental models and may have potential in VCA. The aim of this study was to evaluate the efficacy of low dose IGF-1, CH or their combination (IGF-1+CH) on nerve regeneration following VCA. We used an allogeneic rat hind limb VCA model maintained on low-dose FK506 (tacrolimus) therapy to prevent rejection. Experimental animals received neurotherapeutics administered intra-operatively as multiple intraneural injections. The IGF-1 and IGF-1+CH groups received daily IGF-1 (intramuscular and intraneural injections). Histomorphometry and immunohistochemistry were used to evaluate outcomes at five weeks. Overall, compared to controls, all experimental groups showed improvements in nerve and muscle (gastrocnemius) histomorphometry. The IGF-1 group demonstrated superior distal regeneration as confirmed by Schwann cell (SC) immunohistochemistry as well as some degree of extrafascicular regeneration. IGF-1 and CH effectively promote nerve regeneration after VCA as confirmed by histomorphometric and immunohistochemical outcomes. PMID:27272754

  8. Preclinical Screening for Retinopathy of Prematurity Risk Using IGF1 Levels at 3 Weeks Post-Partum

    PubMed Central

    Pérez-Muñuzuri, Alejandro; Couce-Pico, Ma Luz; Baña-Souto, Ana; López-Suárez, Olalla; Iglesias-Deus, Alicia; Blanco-Teijeiro, José; Fernández-Lorenzo, José Ramón; Fraga-Bermúdez, José María

    2014-01-01

    Following current recommendations for preventing retinopathy of prematurity (ROP) involves screening a large number of patients. We performed a prospective study to establish a useful screening system for ROP prediction and we have determined that measuring serum levels of IGF1 at week three and the presence of sepsis have a high predictive value for the subsequent development of ROP. A total of 145 premature newborn, with birthweight <1500 g and/or <32 weeks gestational age, were enrolled. 26.9% of them showed some form of retinopathy. A significant association was found between the development of retinopathy and each of the following variables: early gestational age, low birthweight, requiring mechanical ventilation, oxygen treatment, intracranial haemorrhage, sepsis during the first three weeks, bronchopulmonary dysplasia, the need for erythrocyte transfusion, erythropoietin treatment, and low levels of serum IGF1 in the third week. A multiple logistic regression analysis was used to obtain curves for the probability of developing ROP, based on the main factors linked with ROP, namely serum levels of IGF1 and presence of sepsis. Such preclinical screening has the ability to identify patients with high-risk of developing retinopathy and should lead to better prediction for ROP, while at the same time optimising the use of clinical resources, both human and material. PMID:24523937

  9. Cell non-autonomous regulation of hepatic IGF-1 and neonatal growth by Kinase Suppressor of Ras 2 (KSR2)

    PubMed Central

    Guo, Lili; Costanzo-Garvey, Diane L.; Smith, Deandra R.; Zavorka, Megan E.; Venable-Kang, Megan; MacDonald, Richard G.; Lewis, Robert E.

    2016-01-01

    Individuals with poor postnatal growth are at risk for cardiovascular and metabolic problems as adults. Here we show that disruption of the molecular scaffold Kinase Suppressor of Ras 2 (KSR2) causes selective inhibition of hepatic GH signaling in neonatal mice with impaired expression of IGF-1 and IGFBP3. ksr2−/− mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development. However, disrupting FGF21 in ksr2−/− mice does not normalize mass, length, or bone density and content in fgf21−/−ksr2−/− mice. Body length, BMC and BMD, but not body mass, are rescued by infection of two-day-old ksr2−/− mice with a recombinant adenovirus encoding human IGF-1. Relative to wild-type mice, GH injections reveal a significant reduction in JAK2 and STAT5 phosphorylation in liver, but not in skeletal muscle, of ksr2−/− mice. However, primary hepatocytes isolated from ksr2−/− mice show no reduction in GH-stimulated STAT5 phosphorylation. These data indicate that KSR2 functions in a cell non-autonomous fashion to regulate GH-stimulated IGF-1 expression in the liver of neonatal mice, which plays a key role in the development of body length. PMID:27561547

  10. Age- and gender-associated changes in the concentrations of serum TGF-1β, DHEA-S and IGF-1 in healthy captive baboons (Papio hamadryas anubis).

    PubMed

    Willis, E L; Wolf, R F; White, G L; McFarlane, D

    2014-01-01

    Age-related changes in the concentration of factors like TGF-1β, DHEA-S and IGF-1 may increase the risk of disease and illnesses in advanced life. A better understanding of these changes would aid in the development of more appropriate treatments and/or preventative care for many conditions associated with age. Due to their similar immune system and vulnerability to pathogens, baboons are an ideal model for humans. However, little research has been done examining the general effects of age in baboons. Therefore, we wanted to further examine the effects of aging in baboons by determining the age-dependent changes in serum TGF-1β, DHEA-S and IGF-1 concentrations. Blood samples were collected during routine health checks in 113-118 captive baboons. In addition, longitudinal samples from 23 to 27 adult individuals were collected an average of 10.7years apart. Both age and gender influenced the concentrations of serum TGF-1β and IGF-1. When both genders were analyzed together, TGF-1β increased 16.1% as adults, compared to younger and older animals, but male and female baboons showed a slightly different temporal pattern of change. IGF-1 decreased with increasing age and males had a 30% greater concentration of IGF-1 than did females. While there was no effect of gender among our population, serum DHEA-S was negatively correlated with age, decreasing by 51.6% in the oldest animals. There were no effects of age or gender on serum IGFBP-3. In longitudinal samples collected from the same individuals, the concentrations of TGF-1β, DHEA-S and IGF-1 were reduced with age. The results presented herein provide additional knowledge of the aging process in baboons and further validate the use of this species as an appropriate model for aging in humans.

  11. Does IGF-1 play a role in the biology of endometrial cancer?

    PubMed

    Majchrzak-Baczmańska, Dominika; Malinowski, Andrzej

    2016-01-01

    Insulin-like growth factor 1 (IGF-1) is a mitogen which plays a key role in regulating cell proliferation, differentiation, and apoptosis. It belongs to the family of proteins also composed of insulin-like growth factor 2 (IGF-2), two types of membrane receptors (IGF-1R and IGF-2R), 6 binding proteins (IGFBP 1-6), hydrolyzing proteases, and reactive molecules binding proteins, which regulate the activity of growth factors. Disturbances in the functioning of IGFBP/IGF/1GF1R can lead to induction of carcinogenesis, which has been demonstrated in breast, prostate or colon cancers. Findings evaluating the role of IGF-1 in endometrial cancer biology are ambiguous and contradictory. Therefore, in the present study, we analyzed the role of IGF-1 in the process of carcinogenesis of endometrial cancer, based on the available literature.

  12. The IGF1 pathway genes and their association with age of puberty in cattle.

    PubMed

    Fortes, Marina R S; Li, Yutao; Collis, Eliza; Zhang, Yuandan; Hawken, Rachel J

    2013-02-01

    Insulin-like growth factor I (somatomedin C) (IGF1) influences gonadotrophin-releasing hormone (GnRH) neurons during puberty, and GnRH release guides pubertal development. Therefore, genes of the IGF1 pathway are biological candidates for the identification of single-nucleotide polymorphisms (SNPs) affecting age of puberty. In a genome-wide association study, genotyped heifers were Tropical Composite (TCOMP, n = 866) or Brahman (BRAH, n = 843), with observation of age at first corpus luteum defining puberty. We examined SNPs in or near genes of the IGF1 pathway and report seven genes associated with age at puberty in cattle: IGF1R, IGFBP2, IGFBP4, PERK (HUGO symbol EIF2AK3), PIK3R1, GSK3B and IRS1. SNPs in the IGF1 receptor (IGF1R) showed the most promising associations: two SNPs were associated with puberty in TCOMP (P < 0.05) and one in BRAH (P = 0.00009). This last SNP explained 2% of the genetic variation (R(2) = 2.04%) for age of puberty in BRAH. Hence, IGF1R was examined further. Additional SNPs were genotyped, and haplotypes were analysed. To test more SNPs in this gene, four new SNPs from dbSNP were selected and genotyped. Single SNP and haploytpe analysis revealed associations with age of puberty in both breeds. There were two haplotypes of 12 IGF1R SNPs associated with puberty in BRAH (P < 0.05) and one in TCOMP (P < 0.05). One haplotype of two SNPs was associated (P < 0.01) with puberty in BRAH, but not in TCOMP. In conclusion, the IGF1 pathway appeared more relevant for age of puberty in Brahman cattle, and IGF1R showed higher significance when compared with other genes from the pathway.

  13. Gefitinib resistance in HCC mahlavu cells: upregulation of CD133 expression, activation of IGF-1R signaling pathway, and enhancement of IGF-1R nuclear translocation.

    PubMed

    Bodzin, Adam S; Wei, Zhengyu; Hurtt, Reginald; Gu, Tina; Doria, Cataldo

    2012-07-01

    Hepatocellular carcinoma (HCC) is the major form of primary liver cancer which accounts for more than half million deaths annually worldwide. While the incidence of HCC is still on the rise, options of treatment are limited and the overall survival rate is poor. The acquisition of cancer drug resistance remains one of the key hurdles to successful treatment. Clearly, a thorough understanding of the underlying mechanisms is needed for new strategies to design novel treatments and/or to improve the current therapies. In the present study, we examined the expression of cancer stem cell (CSC) marker CD133, the activation of insulin-like growth factor 1 receptor (IGF-1R) signaling, and the nuclear translocation of IGF-1R in HCC Mahlavu cells under the treatment of gefitinib, a cancer drug that inhibits epidermal growth factor receptor (EGFR) pathway. Our results demonstrated that Mahlavu cells exhibited strong gefitinib resistance and the CD133 expression level was dramatically increased (from 3.88% to 32%) after drug treatment. In addition, the gefitinib treated cells displayed increased levels of phosphorylation in IGF-1R and Akt, indicating the intensified activation of this cancer-associated signaling pathway. Moreover, we revealed that IGF-1R underwent nuclear translocation in gefitinib treated cells using confocal microscopy. The IGF-1R nuclear translocation was enhanced under gefitinib treatment and appeared in a dose-dependent manner. Our findings suggest that increased IGF-1R nuclear translocation after gefitinib treatment may contribute to the drug resistance and IGF1-R activation, which might also associate with the upregulation of CD133 expression.

  14. The Effects of IGF-1 on TNF-α-Treated DRG Neurons by Modulating ATF3 and GAP-43 Expression via PI3K/Akt/S6K Signaling Pathway.

    PubMed

    Zhang, Lei; Yue, Yaping; Ouyang, Meishuo; Liu, Huaxiang; Li, Zhenzhong

    2017-02-16

    Upregulation of the pro-inflammatory cytokine tumor necrosis factor α (TNF-α) is involved in the development and progression of numerous neurological disorders. Recent reports have challenged the concept that TNF-α exhibits only deleterious effects of pro-inflammatory destruction, and have raised the awareness that it may play a beneficial role in neuronal growth and function in particular conditions, which prompts us to further investigate the role of this cytokine. Insulin-like growth factor-1 (IGF-1) is a cytokine possessing powerful neuroprotective effects in promoting neuronal survival, neuronal differentiation, neurite elongation, and neurite regeneration. The association of IGF-1 with TNF-α and the biological effects, produced by interaction of IGF-1 and TNF-α, on neuronal outgrowth status of primary sensory neurons are still to be clarified. In the present study, using an in vitro model of primary cultured rat dorsal root ganglion (DRG) neurons, we demonstrated that TNF-α challenge at different concentrations elicited diverse biological effects. Higher concentration of TNF-α (10 ng/mL) dampened neurite outgrowth, induced activating transcription factor 3 (ATF3) expression, reduced growth-associated protein 43 (GAP-43) expression, and promoted GAP-43 and ATF3 coexpression, which could be reversed by IGF-1 treatment; while lower concentration of TNF-α (1 ng/mL) promoted neurite sprouting, decreased ATF3 expression, increased GAP-43 expression, and inhibited GAP-43 and ATF3 coexpression, which could be potentiated by IGF-1 supplement. Moreover, IGF-1 administration restored the activation of Akt and p70 S6 kinase (S6K) suppressed by higher concentration of TNF-α (10 ng/mL) challenge. In contrast, lower concentration of TNF-α (1 ng/mL) had no significant effect on Akt or S6K activation, and IGF-1 administration activated these two kinases. The effects of IGF-1 were abrogated by phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. These data

  15. IL-17 and insulin/IGF1 enhance adhesion of prostate cancer cells to vascular endothelial cells through CD44-VCAM-1 interaction

    PubMed Central

    Chen, Chong; Zhang, Qiuyang; Liu, Sen; Parajuli, Keshab R.; Qu, Yine; Mei, Jiandong; Chen, Zhiquan; Zhang, Hui; Khismatullin, Damir B.; You, Zongbing

    2015-01-01

    BACKGROUND Extravasation is a critical step in cancer metastasis, in which adhesion of intravascular cancer cells to the vascular endothelial cells is controlled by cell surface adhesion molecules. The role of interleukin-17 (IL-17), insulin, and insulin-like growth factor 1 (IGF1) in adhesion of prostate cancer cells to the vascular endothelial cells is unknown, which is the subject of the present study. METHODS Human umbilical vein endothelial cells (HUVECs) and human prostate cancer cell lines (PC-3, DU-145, LNCaP, and C4-2B) were analyzed for expression of vascular cell adhesion molecule 1 (VCAM-1), integrins, and cluster of differentiation 44 (CD44) using flow cytometry and Western blot analysis. The effects of IL-17, insulin and IGF1 on VCAM-1 expression and adhesion of prostate cancer cells to HUVECs were examined. The interaction of VCAM-1 and CD44 was assessed using immunoprecipitation assays. RESULTS Insulin and IGF1 acted with IL-17 to increase VCAM-1 expression in HUVECs. PC-3, DU-145, LNCaP, and C4-2B cells expressed β1 integrin but not α4 integrin. CD44 was expressed by PC-3 and DU-145 cells but not by LNCaP or C4-2B cells. When HUVECs were treated with IL-17, insulin or IGF1, particularly with a combination of IL-17 and insulin (or IGF1), adhesion of PC-3 and DU-145 cells to HUVECs was significantly increased. In contrast, adhesion of LNCaP and C4-2B cells to HUVECs was not affected by treatment of HUVECs with IL-17 and/or insulin/IGF1. CD44 expressed in PC-3 cells physically bound to VCAM-1 expressed in HUVECs. CONCLUSIONS CD44-VCAM-1 interaction mediates the adhesion between prostate cancer cells and HUVECs. IL-17 and insulin/IGF1 enhance adhesion of prostate cancer cells to vascular endothelial cells through increasing VCAM-1 expression in the vascular endothelial cells. These findings suggest that IL-17 may act with insulin/IGF1 to promote prostate cancer metastasis. PMID:25683512

  16. Plasma Concentrations of BDNF and IGF-1 in Abstinent Cocaine Users with High Prevalence of Substance Use Disorders: Relationship to Psychiatric Comorbidity

    PubMed Central

    Araos, Pedro; Serrano, Antonia; Romero-Sanchiz, Pablo; Suárez, Juan; Castilla-Ortega, Estela; Barrios, Vicente; Campos-Cloute, Rafael; Ruiz, Juan Jesús; Torrens, Marta; Chowen, Julie Ann; Argente, Jesús; de la Torre, Rafael; Santín, Luis Javier; Villanúa, María Ángeles; Rodríguez de Fonseca, Fernando; Pavón, Francisco Javier

    2015-01-01

    with both primary and cocaine-induced disorders for mood and anxiety disorders. In summary, BDNF, IGF-1 and IGFBP-3 were not affected by a history of pathological use of cocaine supported by the absence of associations with other molecules sensitive to cocaine addiction. However, BDNF was affected by comorbid mood disorders. Further research is necessary to elucidate the role of BDNF and IGF-1 in the transition to cocaine addiction and associated psychiatric comorbidity. PMID:25734326

  17. Plasma concentrations of BDNF and IGF-1 in abstinent cocaine users with high prevalence of substance use disorders: relationship to psychiatric comorbidity.

    PubMed

    Pedraz, María; Martín-Velasco, Ana Isabel; García-Marchena, Nuria; Araos, Pedro; Serrano, Antonia; Romero-Sanchiz, Pablo; Suárez, Juan; Castilla-Ortega, Estela; Barrios, Vicente; Campos-Cloute, Rafael; Ruiz, Juan Jesús; Torrens, Marta; Chowen, Julie Ann; Argente, Jesús; de la Torre, Rafael; Santín, Luis Javier; Villanúa, María Ángeles; Rodríguez de Fonseca, Fernando; Pavón, Francisco Javier

    2015-01-01

    with both primary and cocaine-induced disorders for mood and anxiety disorders. In summary, BDNF, IGF-1 and IGFBP-3 were not affected by a history of pathological use of cocaine supported by the absence of associations with other molecules sensitive to cocaine addiction. However, BDNF was affected by comorbid mood disorders. Further research is necessary to elucidate the role of BDNF and IGF-1 in the transition to cocaine addiction and associated psychiatric comorbidity.

  18. IGF1 as a Potential Treatment for Rett Syndrome: Safety Assessment in Six Rett Patients.

    PubMed

    Pini, Giorgio; Scusa, Maria Flora; Congiu, Laura; Benincasa, Alberto; Morescalchi, Paolina; Bottiglioni, Ilaria; Di Marco, Pietro; Borelli, Paolo; Bonuccelli, Ubaldo; Della-Chiesa, Andrea; Prina-Mello, Adriele; Tropea, Daniela

    2012-01-01

    Rett syndrome (RTT) is a devastating neurodevelopmental disorder that affects one in ten thousand girls and has no cure. The majority of RTT patients display mutations in the gene that codes for the methyl-CpG-binding protein 2 (MeCP2). Clinical observations and neurobiological analysis of mouse models suggest that defects in the expression of MeCP2 protein compromise the development of the central nervous system, especially synaptic and circuit maturation. Thus, agents that promote brain development and synaptic function, such as insulin-like growth factor 1 (IGF1), are good candidates for ameliorating the symptoms of RTT. IGF1 and its active peptide, (1-3) IGF1, cross the blood brain barrier, and (1-3) IGF1 ameliorates the symptoms of RTT in a mouse model of the disease; therefore they are ideal treatments for neurodevelopmental disorders, including RTT. We performed a pilot study to establish whether there are major risks associated with IGF1 administration in RTT patients. Six young girls with classic RTT received IGF1 subcutaneous injections twice a day for six months, and they were regularly monitored by their primary care physicians and by the unit for RTT in Versilia Hospital (Italy). This study shows that there are no risks associated with IGF1 administration.

  19. IGF1R Signaling in Ewing Sarcoma Is Shaped by Clathrin-/Caveolin-Dependent Endocytosis

    PubMed Central

    Martins, Ana Sofia; Ordóñez, José Luis; Amaral, Ana Teresa; Prins, Frans; Floris, Giuseppe; Debiec-Rychter, Maria; Hogendoorn, Pancras C. W.; de Alava, Enrique

    2011-01-01

    Receptor endocytosis is critical for cell signaling. IGF1R mediates an autocrine loop that is de-regulated in Ewing Sarcoma (ES) cells. Here we study the impact of IGF1R internalization, mediated by clathrin and caveolin-1 (CAV1), in ES signaling. We used clathrin and CAV1-siRNA to interfere in clathrin- and caveolin-dependent endocytosis. Chlorpromazine (CPMZ) and methyl-beta-cyclo-dextrin (MCD) were also used in order to inhibit clathrin- and caveolin-dependent endocytosis, respectively. We analyzed IGF1R internalization and co-localization with clathrin and CAV1 upon ligand binding, as well as the status of the IGF1R pathway, cellular proliferation, and the apoptosis of interfered and inhibited ES cells. We performed a high-throughput tyrosine kinase phosphorylation assay to analyze the effects of combining the IGF1R tyrosine kinase inhibitor AEW541 (AEW) with CPMZ or MCD on the intracellular phospho-proteome. We observed that IGF1R is internalized upon ligand binding in ES cells and that this process is dependent on clathrin or CAV1. The blockage of receptor internalization inhibited AKT and MAPK phosphorylation, reducing the proliferative rate of ES cells and increasing the levels of apoptosis. Combination of AEW with CPMZ or MCD largely enhanced these effects. CAV1 and clathrin endocytosis controls IGF1R internalization and signaling and has a profound impact on ES IGF1R-promoted survival signaling. We propose the combination of tyrosine-kinase inhibitors with endocytosis inhibitors as a new therapeutic approach to achieve a stronger degree of receptor inhibition in this, or other neoplasms dependent on IGF1R signaling. PMID:21611203

  20. Adipogenic Differentiation of hMSCs is Mediated by Recruitment of IGF-1r Onto the Primary Cilium Associated With Cilia Elongation.

    PubMed

    Dalbay, Melis T; Thorpe, Stephen D; Connelly, John T; Chapple, J Paul; Knight, Martin M

    2015-06-01

    Primary cilia are single non-motile organelles that provide a highly regulated compartment into which specific proteins are trafficked as a critical part of various signaling pathways. The absence of primary cilia has been shown to prevent differentiation of human mesenchymal stem cells (hMSCs). Changes in primary cilia length are crucial for regulating signaling events; however it is not known how alterations in cilia structure relate to differentiation. This study tested the hypothesis that changes in primary cilia structure are required for stem cell differentiation. hMSCs expressed primary cilia that were labeled with acetylated alpha tubulin and visualized by confocal microscopy. Chemically induced differentiation resulted in lineage specific changes in cilia length and prevalence which were independent of cell cycle. In particular, adipogenic differentiation resulted in cilia elongation associated with the presence of dexamethasone, while insulin had an inhibitory effect on cilia length. Over a 7-day time course, adipogenic differentiation media resulted in cilia elongation within 2 days followed by increased nuclear PPARγ levels; an early marker of adipogenesis. Cilia elongation was associated with increased trafficking of insulin-like growth factor-1 receptor β (IGF-1Rβ) into the cilium. This was reversed on inhibition of elongation by IFT-88 siRNA transfection, which also decreased nuclear PPARγ. This is the first study to show that adipogenic differentiation requires primary cilia elongation associated with the recruitment of IGF-1Rβ onto the cilium. This study may lead to the development of cilia-targeted therapies for controlling adipogenic differentiation and associated conditions such as obesity.

  1. [Growth hormone and IGF-1 as doping agents in competitive sport].

    PubMed

    Jóźków, Paweł; Medraś, Marek

    2009-01-01

    Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are often used by athletes as doping agents. It is estimated that up to 25% of sportsmen using anabolic-androgenic steroids also take GH. Available data do not confirm the influence of GH or IGF-1 preparations on physical performance improvement. However, there is some evidences for many adverse effects in athletes using this form of doping. Blood tests to detect growth hormone abuse are available since several years. Surprisingly, no one has been proven to use illegal doping agents influencing GH/IGF-1 axis.

  2. The GH/IGF-1 axis in a critical period early in life determines cellular DNA repair capacity by altering transcriptional regulation of DNA repair-related genes: implications for the developmental origins of cancer.

    PubMed

    Podlutsky, Andrej; Valcarcel-Ares, Marta Noa; Yancey, Krysta; Podlutskaya, Viktorija; Nagykaldi, Eszter; Gautam, Tripti; Miller, Richard A; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2017-02-23

    Experimental, clinical, and epidemiological findings support the concept of developmental origins of health and disease (DOHAD), suggesting that early-life hormonal influences during a sensitive period around adolescence have a powerful impact on cancer morbidity later in life. The endocrine changes that occur during puberty are highly conserved across mammalian species and include dramatic increases in circulating GH and IGF-1 levels. Importantly, patients with developmental IGF-1 deficiency due to GH insensitivity (Laron syndrome) do not develop cancer during aging. Rodents with developmental GH/IGF-1 deficiency also exhibit significantly decreased cancer incidence at old age, marked resistance to chemically induced carcinogenesis, and cellular resistance to genotoxic stressors. Early-life treatment of GH/IGF-1-deficient mice and rats with GH reverses the cancer resistance phenotype; however, the underlying molecular mechanisms remain elusive. The present study was designed to test the hypothesis that developmental GH/IGF-1 status impacts cellular DNA repair mechanisms. To achieve that goal, we assessed repair of γ-irradiation-induced DNA damage (single-cell gel electrophoresis/comet assay) and basal and post-irradiation expression of DNA repair-related genes (qPCR) in primary fibroblasts derived from control rats, Lewis dwarf rats (a model of developmental GH/IGF-1 deficiency), and GH-replete dwarf rats (GH administered beginning at 5 weeks of age, for 30 days). We found that developmental GH/IGF-1 deficiency resulted in persisting increases in cellular DNA repair capacity and upregulation of several DNA repair-related genes (e.g., Gadd45a, Bbc3). Peripubertal GH treatment reversed the radiation resistance phenotype. Fibroblasts of GH/IGF-1-deficient Snell dwarf mice also exhibited improved DNA repair capacity, showing that the persisting influence of peripubertal GH/IGF-1 status is not species-dependent. Collectively, GH/IGF-1 levels during a critical period

  3. TNF alpha inhibits myogenic differentiation of C2C12 cells through NF-κB activation and impairment of IGF-1 signaling pathway.

    PubMed

    Zhao, Q; Yang, S T; Wang, J J; Zhou, J; Xing, S S; Shen, C C; Wang, X X; Yue, Y X; Song, J; Chen, M; Wei, Y Y; Zhou, Q P; Dai, T; Song, Y H

    2015-03-20

    Cachexia or muscle wasting is a common condition that occurs in many chronic diseases. The wasting conditions are characterized by increased levels of TNF-α which was also known as cachectin in the past. But how TNF-α exerts its cachetic effects remains controversial. To clarify this issue, we investigated the impact of TNF-α on C2C12 cell myogenic differentiation. Our results demonstrate that myotube formation was completely inhibited by TNF-α when added to differentiating C2C12 myoblasts. The inhibitory effect of TNF-α on differentiation was accompanied by activation of NF-κB and down regulation of myogenin and Akt. Importantly, TNF-α's effect on differentiation was abolished when IGF-1 was added to the culture. IGF-1 treatment also inhibited NF-κB reporter activity and restored Akt levels. Our data suggest that TNF-α inhibits myogenic differentiation through NF-κB activation and impairment of IGF-1 signaling pathway. The reversal of TNF-α induced inhibition of myogenesis by IGF-1 may have significant therapeutic potential.

  4. Differential expression of IGF-1 mRNA isoforms in colorectal carcinoma and normal colon tissue.

    PubMed

    Kasprzak, Aldona; Szaflarski, Witold; Szmeja, Jacek; Andrzejewska, Małgorzata; Przybyszewska, Wiesława; Kaczmarek, Elżbieta; Koczorowska, Maria; Kościński, Tomasz; Zabel, Maciej; Drews, Michał

    2013-01-01

    The insulin-like growth factor (IGF)-1 gene consists of 6 exons resulting in the expression of 6 variant forms of mRNA (IA, IB, IC, IIA, IIB and IIC) due to an alternative splicing. The mechanisms of IGF-1 gene splicing and the role of local expression manifested by IGF-1 mRNA variants in colorectal carcinoma (CRC) have not been extensively investigated. Therefore, the aim of our study was to analyse the expression of IGF-1 mRNA isoforms [A, B, C, P1 (class I) and P2 (class II)], as well as the protein expression in CRC and control samples isolated from 28 patients. The expression of Ki-67 was also analysed and clinical data were obtained. For this purpose, we used quantitative real-time PCR (qPCR) and immunocytochemistry. The expression of mRNAs coding for all splicing isoforms of IGF-1 was observed in every tissue sample studied, with a significantly lower expression noted in the CRC as compared to the control samples. The cytoplasmic expression of IGF-1 protein was found in 50% of the CRC and in ~40% of the non-tumor tissues; however, no significant quantitative inter-group differences were observed. The expression of the IGF-1 gene in the 2 groups of tissues was controlled by the P1 and P2 promoters in a similar manner. No significant differences were detected in the expression of the IGF-1 A and B isoforms; however, their expression was significantly higher compared to that of isoform C. No significant differences were observed between the expression of Ki-67 mRNA in the CRC and control tissue even though the expression of the Ki-67 protein was higher in the CRC compared to the control samples. Ki-67 protein expression was associated with the macroscopic and microscopic aspects of CRC. A significant positive correlation was found between the local production of total mRNA and isoform A and the expression of Ki-67 mRNA, although only in the non-tumor tissues. In CRC samples, the local expression of the total IGF-1 mRNA and all splicing isoforms of IGF-1 m

  5. IGF-1 Levels are Inversely Associated With Metabolic Syndrome in Obstructive Sleep Apnea

    PubMed Central

    Izumi, Suelem; Ribeiro-Filho, Fernando F.; Carneiro, Gláucia; Togeiro, Sônia M.; Tufik, Sérgio; Zanella, Maria T.

    2016-01-01

    Study Objectives: This study examined insulin-like growth factor-1 (IGF-1) production and its association with the metabolic syndrome (MS) in men with obstructive sleep apnea (OSA). Methods: In total, 47 overweight and obese men who had been referred for suspected OSA underwent polysomnography and were classified based on the apnea-hypopnea index (AHI) into three groups: no OSA, < 5 events/h (n = 11); mild OSA, ≥ 5 to < 15 events/h (n = 8); and moderate-severe OSA, ≥ 15 events/h (n = 28). The assessment of the somatotropic axis function included IGF-1 measurement. MS was diagnosed according to the National Cholesterol Education Program guidelines. Results: IGF-1 level in the moderate-severe OSA group was lower than in the no-OSA group (156.8 ± 54.3 μg/L versus 225.5 ± 80.5 μg/L; p = 0.013). IGF-1 level was negatively correlated with body mass index, waist circumference (WC), AHI, and sleep duration with oxygen (O2) saturation < 90% and positively correlated with the average and minimum O2 saturation (p = 0.027). In a multivariable linear regression, considering WC and minimum O2 saturation as independent variables, only the minimum O2 saturation was a predictor of low IGF-1 levels. The proportions of patients with MS were different between the three groups (18.2% in no OSA; 25% in mild OSA, and 57.1% in moderate-severe OSA; p = 0.047). Furthermore, in the lowest tertile of IGF-1 value, 66.7% of patients were affected by MS (p = 0.049). Hemoglobin (Hb)A1c correlated negatively with the minimum O2 saturation and IGF-1 levels. However, in multivariable linear regression only IGF-1 levels were a predictor of HbA1c levels. Conclusion: The occurrence of OSA is associated with a reduction in IGF-1 levels. IGF-1 alterations in OSA also seem to be associated with a higher prevalence of MS. Citation: Izumi S, Ribeiro-Filho FF, Carneiro G, Togeiro SM, Tufik S, Zanella MT. IGF-1 levels are inversely associated with metabolic syndrome in obstructive sleep apnea. J Clin

  6. Genetic variation in IGF1 predicts renal cell carcinoma susceptibility and prognosis in Chinese population

    PubMed Central

    Cao, Qiang; Liang, Chao; Xue, Jianxin; Li, Pu; Li, Jie; Wang, Meilin; Zhang, Zhengdong; Qin, Chao; Lu, Qiang; Hua, Lixin; Shao, Pengfei; Wang, Zengjun

    2016-01-01

    Insulin-like growth factor 1 (IGF1) and IGF binding protein 3 (IGFBP3) play an important role in the development and progression of renal cell carcinoma (RCC). We evaluated the association of functional polymorphisms in IGF1 and IGFBP3 with susceptibility and prognosis of RCC. We genotyped nine potentially functional polymorphisms in IGF1 and IGFBP3 and assessed their association with risk of RCC in a two-stage case-control study compromising 1027 cases and 1094 controls, and with prognosis in a cohort of 311 patients. We found rs5742714 in the 3′-UTR of IGF1 was significantly associated with risk and prognosis of RCC. In the combined set, the rs5742714 GC/CC genotypes were significantly associated with decreased risk of RCC compared with the GG genotype (OR = 0.82; 95% CI = 0.68–0.98, P = 0.002). Furthermore, patients with the rs5742714 GC/CC genotypes showed improved survival than those with the GG genotype (Log-rank P = 0.025, HR = 0.36, 95% CI = 0.14–0.93). Besides, the rs5742714 GC/CC genotypes were associated with significantly decreased expression of IGF1 mRNA and lower IGF1 serum levels. Moreover, the luciferase reporter assays revealed the potential effect of rs5742714 genotype on the binding of microRNAs to IGF1. Our findings suggest that the IGF1 polymorphism rs5742714 may be a genetic predictor of susceptibility and prognosis of RCC. PMID:27976731

  7. miR-143 inhibits bladder cancer cell proliferation and enhances their sensitivity to gemcitabine by repressing IGF-1R signaling

    PubMed Central

    Wang, Hengbing; Li, Qi; Niu, Xiaobing; Wang, Gongcheng; Zheng, Sinian; Fu, Guangbo; Wang, Zengjun

    2017-01-01

    microRNAs (miRNAs) are a class of small RNAs that regulate gene expression. It has been demonstrated that aberrant miRNA expression is associated with cancer development and carcinogenesis. Altered miRNA expression has been suggested to occur in bladder cancer. In other cancer systems, studies have indicated that miR-143, as a tumor suppressor gene, plays essential roles in cancer progression. However, its role in bladder cancer has yet to be elucidated. In the present study, we observed that miR-143 expression was downregulated in human bladder cancer tissues and cells, and that its levels were negatively correlated with bladder cancer clinical stages. We further demonstrated that insulin-like growth factor-1 receptor (IGF-1R) is a functional target of miR-143. Their expression levels were inversely correlated in bladder cancer samples. Overexpression of miR-143 inhibited cell proliferation and promoted chemosensitivity of bladder cancer 5637 cells to gemcitabine. Consistently, small interfering RNA-mediated knockdown of IGF-1R phenocopied miR-143 overexpression. Notably, the expression of IGF-1R is a predictor of patient prognosis. Collectively, our findings indicate that miR-143 is a valuable biomarker for bladder cancer. The miR-143/IGF-1R axis is associated with bladder cancer drug resistance and patient survival. PMID:28123579

  8. IRS-2 branch of IGF-1 receptor signaling is essential for appropriate timing of myelination.

    PubMed

    Freude, Susanna; Leeser, Uschi; Müller, Marita; Hettich, Moritz M; Udelhoven, Michael; Schilbach, Katharina; Tobe, Kazuyuki; Kadowaki, Takashi; Köhler, Christoph; Schröder, Hannsjörg; Krone, Wilhelm; Brüning, Jens C; Schubert, Markus

    2008-11-01

    Insulin-like growth factor (IGF)-1 increases proliferation, inhibits apoptosis and promotes differentiation of oligodendrocytes and their precursor cells, indicating an important function for IGF-1 receptor (IGF-1R) signaling in myelin development. The insulin receptor substrates (IRS), IRS-1 and -2 serve as intracellular IGF-1R adaptor proteins and are expressed in neurons, oligodendrocytes and their precursors. To address the role of IRS-2 in myelination, we analyzed myelination in IRS-2 deficient (IRS-2(-/-)) mice and age-matched controls during postnatal development. Interestingly, expression of the most abundant myelin proteins, myelin basic protein and proteolipid protein was reduced in IRS-2(-/-) brains at postnatal day 10 (P10) as compared to controls. myelin basic protein immunostaining in P10-IRS-2(-/-) mice revealed a reduced immunostaining, but an unchanged regional distribution pattern. In cerebral myelin isolates at P10 unaltered relative expression of different myelin proteins was found, indicating quantitatively reduced but not qualitatively altered myelination. Interestingly, up-regulation of IRS-1 expression and increased IGF-1R signaling were observed in IRS-2(-/-) mice at P10-14, indicating a compensatory mechanism to overcome IRS-2 deficiency. Adult IRS-2(-/-) mice showed unaltered myelination and motor function. Furthermore, in neuronal/brain-specific insulin receptor knockout mice myelination was unchanged. Thus, our experiments reveal that IGF-1R/IRS-2 mediated signals are critical for appropriate timing of myelination in vivo.

  9. Domain-dependent effects of insulin and IGF-1 receptors on signalling and gene expression

    PubMed Central

    Cai, Weikang; Sakaguchi, Masaji; Kleinridders, Andre; Gonzalez-Del Pino, Gonzalo; Dreyfuss, Jonathan M.; O'Neill, Brian T.; Ramirez, Alfred K.; Pan, Hui; Winnay, Jonathon N.; Boucher, Jeremie; Eck, Michael J.; Kahn, C. Ronald

    2017-01-01

    Despite a high degree of homology, insulin receptor (IR) and IGF-1 receptor (IGF1R) mediate distinct cellular and physiological functions. Here, we demonstrate how domain differences between IR and IGF1R contribute to the distinct functions of these receptors using chimeric and site-mutated receptors. Receptors with the intracellular domain of IGF1R show increased activation of Shc and Gab-1 and more potent regulation of genes involved in proliferation, corresponding to their higher mitogenic activity. Conversely, receptors with the intracellular domain of IR display higher IRS-1 phosphorylation, stronger regulation of genes in metabolic pathways and more dramatic glycolytic responses to hormonal stimulation. Strikingly, replacement of leucine973 in the juxtamembrane region of IR to phenylalanine, which is present in IGF1R, mimics many of these signalling and gene expression responses. Overall, we show that the distinct activities of the closely related IR and IGF1R are mediated by their intracellular juxtamembrane region and substrate binding to this region. PMID:28345670

  10. IGF-1 Receptor Differentially Regulates Spontaneous and Evoked Transmission via Mitochondria at Hippocampal Synapses

    PubMed Central

    Gazit, Neta; Vertkin, Irena; Shapira, Ilana; Helm, Martin; Slomowitz, Edden; Sheiba, Maayan; Mor, Yael; Rizzoli, Silvio; Slutsky, Inna

    2016-01-01

    Summary The insulin-like growth factor-1 receptor (IGF-1R) signaling is a key regulator of lifespan, growth, and development. While reduced IGF-1R signaling delays aging and Alzheimer’s disease progression, whether and how it regulates information processing at central synapses remains elusive. Here, we show that presynaptic IGF-1Rs are basally active, regulating synaptic vesicle release and short-term plasticity in excitatory hippocampal neurons. Acute IGF-1R blockade or transient knockdown suppresses spike-evoked synaptic transmission and presynaptic cytosolic Ca2+ transients, while promoting spontaneous transmission and resting Ca2+ level. This dual effect on transmitter release is mediated by mitochondria that attenuate Ca2+ buffering in the absence of spikes and decrease ATP production during spiking activity. We conclude that the mitochondria, activated by IGF-1R signaling, constitute a critical regulator of information processing in hippocampal neurons by maintaining evoked-to-spontaneous transmission ratio, while constraining synaptic facilitation at high frequencies. Excessive IGF-1R tone may contribute to hippocampal hyperactivity associated with Alzheimer’s disease. Video Abstract PMID:26804996

  11. EEN regulates the proliferation and survival of multiple myeloma cells by potentiating IGF-1 secretion

    SciTech Connect

    Huang, Er-Wen; Xue, Sheng-Jiang; Li, Xiao-Yan; Xu, Suo-Wen; Cheng, Jian-Ding; Zheng, Jin-Xiang; Shi, He; Lv, Guo-Li; Li, Zhi-Gang; Li, Yue; Liu, Chang-Hui; Chen, Xiao-Hui; Liu, Hong; Li, Jie; Liu, Chao

    2014-05-02

    Highlights: • Levels of EEN expression paralleled with the rate of cell proliferation. • EEN was involved in the proliferation and survival of multiple myeloma (MM) cells. • EEN regulated the activity of IGF-1-Akt/mTOR pathway. • EEN regulated proliferation and survival of MM cells by enhancing IGF-1 secretion. - Abstract: The molecular mechanisms of multiple myeloma are not well defined. EEN is an endocytosis-regulating molecule. Here we report that EEN regulates the proliferation and survival of multiple myeloma cells, by regulating IGF-1 secretion. In the present study, we observed that EEN expression paralleled with cell proliferation, EEN accelerated cell proliferation, facilitated cell cycle transition from G1 to S phase by regulating cyclin-dependent kinases (CDKs) pathway, and delayed cell apoptosis via Bcl2/Bax-mitochondrial pathway. Mechanistically, we found that EEN was indispensable for insulin-like growth factor-1 (IGF-1) secretion and the activation of protein kinase B-mammalian target of rapamycin (Akt-mTOR) pathway. Exogenous IGF-1 overcame the phenotype of EEN depletion, while IGF-1 neutralization overcame that of EEN over-expression. Collectively, these data suggest that EEN may play a pivotal role in excessive cell proliferation and insufficient cell apoptosis of bone marrow plasma cells in multiple myeloma. Therefore, EEN may represent a potential diagnostic marker or therapeutic target for multiple myeloma.

  12. Modeling the effect of insulin-like growth factor-1 on human cell growth.

    PubMed

    Phillips, Gemma M A; Shorten, Paul R; Wake, Graeme C; Guan, Jian

    2015-01-01

    Insulin-like growth factor-1 (IGF-1) plays a key role in human growth and development. The interactions of IGF-1 with IGF-1 receptors and IGF-1 binding proteins (IGFBPs) regulate IGF-1 function. Recent research suggests that a metabolite of IGF-1, cyclo-glycyl-proline (cGP), has a role in regulating IGF-1 homeostasis. A component of this interaction is believed to be the competitive binding of IGF-1 and cGP to IGFBPs. In this paper we describe a mathematical model of the interaction between IGF-1 and cGP on human cell growth. The model can be used to understand the interaction between IGF-1, IGFBPs, cGP and IGF-1 receptors along with the kinetics of cell growth. An explicit model of the known interactions between IGF-1, cGP, IGFBPs, IGF-1 receptors explained a large portion of the variance in cell growth (R(2) = 0.83). An implicit model of the interactions between IGF-1, cGP, IGFBPs, IGF-1 receptors that included a hypothesized feedback of cGP on IGF-1 receptors explained nonlinear features of interaction between IGF-1 and cGP not described by the explicit model (R(2) = 0.84). The model also explained the effect of IGFBP antibody on the interaction between cGP and IGF-1 (R(2) = 0.78). This demonstrates that the competitive binding of IGF-1 and cGP to IGFBPs plays a large role in the interaction between IGF-1 and cGP, but that other factors potentially play a role in the interaction between cGP and IGF-1. These models can be used to predict the complex interaction between IGF-1 and cGP on human cell growth and form a basis for further research in this field.

  13. Associations between genetic variants in the promoter region of the insulin-like growth factor-1 (IGF1) gene and blood serum IGF1 concentration in Hanwoo cattle.

    PubMed

    Chung, H Y; Choi, Y J; Park, H N; Davis, M E

    2015-04-10

    In this study, we investigated the associations between genetic variants in the promoter region of the insulin-like growth factor-1 (IGF1) gene and blood serum IGF1 concentration in Hanwoo cattle. Polymerase chain reaction primers were based on GenBank accession No. AF404761 and amplified approximately 533-bp segments. Newly identified sequences were submitted to GenBank (accession No. DQ267493). Sequence analysis revealed that genetic variants were located at a nucleotide position 323 for the nucleotide substitution C/A that was first reported in this study and positions 326-349 for a repeat motif (CA10-11). The allele frequencies of g.323C>A were 0.264 (C) and 0.736 (A) without significant deviation from Hardy-Weinberg equilibrium. Frequencies of the repeat motif CA(10) and CA(11) were 0.604 and 0.396, respectively. Statistical analysis revealed that the genetic variation g.323C>A was significantly associated with blood serum IGF1 concentrations with significant additive genetic effects, whereas no associations were found for the repeat motif. IGF1 concentrations were positively (r = 0.453) and negatively (r = -0.445) correlated with weights in the growing stages (16-21 months) and late fattening stages (22-30 months), respectively. The results of the present study and future genotypic data for Hanwoo beef cattle based on the robust genetic variation of IGF1 will provide critical information for genetic improvement and will have a large impact on commercial markets.

  14. Circadian clocks govern calorie restriction-mediated life span extension through BMAL1- and IGF-1-dependent mechanisms.

    PubMed

    Patel, Sonal A; Chaudhari, Amol; Gupta, Richa; Velingkaar, Nikkhil; Kondratov, Roman V

    2016-04-01

    Calorie restriction (CR) increases longevity in many species by unknown mechanisms. The circadian clock was proposed as a potential mediator of CR. Deficiency of the core component of the circadian clock-transcriptional factor BMAL1 (brain and muscle ARNT [aryl hydrocarbon receptor nuclear translocator]-like protein 1)-results in accelerated aging. Here we investigated the role of BMAL1 in mechanisms of CR. The 30% CR diet increased the life span of wild-type (WT) mice by 20% compared to mice on anad libitum(AL) diet but failed to increase life span ofBmal1(-/-)mice. BMAL1 deficiency impaired CR-mediated changes in the plasma levels of IGF-1 and insulin. We detected a statistically significantly reduction of IGF-1 in CRvs.AL by 50 to 70% in WT mice at several daily time points tested, while inBmal1(-/-)the reduction was not significant. Insulin levels in WT were reduced by 5 to 9%, whileBmal1(-/-)induced it by 10 to 35% at all time points tested. CR up-regulated the daily average expression ofBmal1(by 150%) and its downstream target genesPeriods(by 470% forPer1and by 130% forPer2). We propose that BMAL1 is an important mediator of CR, and activation of BMAL1 might link CR mechanisms with biologic clocks.-Patel, S. A., Chaudhari, A., Gupta, R., Velingkaar, N., Kondratov, R. V. Circadian clocks govern calorie restriction-mediated life span extension through BMAL1- and IGF-1-dependent mechanisms.

  15. BI 885578, a Novel IGF1R/INSR Tyrosine Kinase Inhibitor with Pharmacokinetic Properties That Dissociate Antitumor Efficacy and Perturbation of Glucose Homeostasis.

    PubMed

    Sanderson, Michael P; Apgar, Joshua; Garin-Chesa, Pilar; Hofmann, Marco H; Kessler, Dirk; Quant, Jens; Savchenko, Alexander; Schaaf, Otmar; Treu, Matthias; Tye, Heather; Zahn, Stephan K; Zoephel, Andreas; Haaksma, Eric; Adolf, Günther R; Kraut, Norbert

    2015-12-01

    Inhibition of the IGF1R, INSRA, and INSRB receptor tyrosine kinases represents an attractive approach of pharmacologic intervention in cancer, owing to the roles of the IGF1R and INSRA in promoting cell proliferation and survival. However, the central role of the INSRB isoform in glucose homeostasis suggests that prolonged inhibition of this kinase could result in metabolic toxicity. We describe here the profile of the novel compound BI 885578, a potent and selective ATP-competitive IGF1R/INSR tyrosine kinase inhibitor distinguished by rapid intestinal absorption and a short in vivo half-life as a result of rapid metabolic clearance. BI 885578, administered daily per os, displayed an acceptable tolerability profile in mice at doses that significantly reduced the growth of xenografted human GEO and CL-14 colon carcinoma tumors. We found that treatment with BI 885578 is accompanied by increases in circulating glucose and insulin levels, which in turn leads to compensatory hyperphosphorylation of muscle INSRs and subsequent normalization of blood glucose within a few hours. In contrast, the normalization of IGF1R and INSR phosphorylation in GEO tumors occurs at a much slower rate. In accordance with this, BI 885578 led to a prolonged inhibition of cell proliferation and induction of apoptosis in GEO tumors. We propose that the remarkable therapeutic window observed for BI 885578 is achieved by virtue of the distinctive pharmacokinetic properties of the compound, capitalizing on the physiologic mechanisms of glucose homeostasis and differential levels of IGF1R and INSR expression in tumors and normal tissues.

  16. Crosstalk between the IGF-1R/AKT/mTORC1 pathway and the tumor suppressors p53 and p27 determines cisplatin sensitivity and limits the effectiveness of an IGF-1R pathway inhibitor

    PubMed Central

    Davaadelger, Batzaya; Duan, Lei; Perez, Ricardo E.; Gitelis, Steven; Maki, Carl G.

    2016-01-01

    The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is aberrantly activated in multiple cancers and can promote proliferation and chemotherapy resistance. Multiple IGF-1R inhibitors have been developed as potential therapeutics. However, these inhibitors have failed to increase patient survival when given alone or in combination with chemotherapy agents. The reason(s) for the disappointing clinical effect of these inhibitors is not fully understood. Cisplatin (CP) activated the IGF-1R/AKT/mTORC1 pathway and stabilized p53 in osteosarcoma (OS) cells. p53 knockdown reduced IGF-1R/AKT/mTORC1 activation by CP, and IGF-1R inhibition reduced the accumulation of p53. These data demonstrate positive crosstalk between p53 and the IGF-1R/AKT/mTORC1 pathway in response to CP. Further studies showed the effect of IGF-1R inhibition on CP response is dependent on p53 status. In p53 wild-type cells treated with CP, IGF-1R inhibition increased p53s apoptotic function but reduced p53-dependent senescence, and had no effect on long term survival. In contrast, in p53-null/knockdown cells, IGF-1R inhibition reduced apoptosis in response to CP and increased long term survival. These effects were due to p27 since IGF-1R inhibition stabilized p27 in CP-treated cells, and p27 depletion restored apoptosis and reduced long term survival. Together, the results demonstrate 1) p53 expression determines the effect of IGF-1R inhibition on cancer cell CP response, and 2) crosstalk between the IGF-1R/AKT/mTORC1 pathway and p53 and p27 can reduce cancer cell responsiveness to chemotherapy and may ultimately limit the effectiveness of IGF-1R pathway inhibitors in the clinic. PMID:27050276

  17. Delivery of plasmid IGF-1 to chondrocytes via cationized gelatin nanoparticles.

    PubMed

    Xu, Ximing; Capito, Ramille M; Spector, Myron

    2008-01-01

    The objective of the present study was to investigate the use of gelatin and cationized-gelatin nanoparticles for the nonviral delivery of the plasmid DNA encoding for insulin-like growth factor (IGF)-1 to adult canine articular chondrocytes in vitro; plasmid for enhanced green fluorescence protein (EGFP) was used as a marker gene. The spherical cationized gelatin nanoparticles were on average 172 nm in diameter, compared with the often ellipsoid-shaped unmodified (noncationized) gelatin particles that generally appeared to be 10 mum to greater than 20 mum in length. The zeta potential of the positively charged cationized gelatin nanoparticles containing the plasmid was around 20 mV compared with about 2 mV for the unmodified gelatin particles. There was no noticeable fluorescence from the cells treated with the nanoparticles prepared with the original (noncationized) gelatin particles containing the pEGFP. In contrast, numerous cells in the group transfected with the cationized gelatin-pEGFP nanoparticles were found to fluoresce demonstrating the transfection of the cells. There was five-fold elevation in the amount of IGF-1 produced by the cells treated with the cationized gelatin nanoparticles containing the IGF-1 plasmid compared with the unmodified (noncationized) gelatin particles. There was a clear effect of varying the weight ratio of plasmid IGF-1 in the cationized gelatin nanoparticles on the IGF-1 in the medium of cells exposed to the nanoparticles for 5 h. A peak in the amount of released IGF-1 was detected at a gelatin:IGF-1 weight ratio of 250:1.

  18. Insulin, IGF-1 and GLP-1 signaling in neurodegenerative disorders: targets for disease modification?

    PubMed

    Bassil, Fares; Fernagut, Pierre-Olivier; Bezard, Erwan; Meissner, Wassilios G

    2014-07-01

    Insulin and Insulin Growth Factor-1 (IGF-1) play a major role in body homeostasis and glucose regulation. They also have paracrine/autocrine functions in the brain. The Insulin/IGF-1 signaling pathway contributes to the control of neuronal excitability, nerve cell metabolism and cell survival. Glucagon like peptide-1 (GLP-1), known as an insulinotropic hormone has similar functions and growth like properties as insulin/IGF-1. Growing evidence suggests that dysfunction of these pathways contribute to the progressive loss of neurons in Alzheimer's disease (AD) and Parkinson's disease (PD), the two most frequent neurodegenerative disorders. These findings have led to numerous studies in preclinical models of neurodegenerative disorders targeting insulin/IGF-1 and GLP-1 signaling with currently available anti-diabetics. These studies have shown that administration of insulin, IGF-1 and GLP-1 agonists reverses signaling abnormalities and has positive effects on surrogate markers of neurodegeneration and behavioral outcomes. Several proof-of-concept studies are underway that attempt to translate the encouraging preclinical results to patients suffering from AD and PD. In the first part of this review, we discuss physiological functions of insulin/IGF-1 and GLP-1 signaling pathways including downstream targets and receptors distribution within the brain. In the second part, we undertake a comprehensive overview of preclinical studies targeting insulin/IGF-1 or GLP-1 signaling for treating AD and PD. We then detail the design of clinical trials that have used anti-diabetics for treating AD and PD patients. We close with future considerations that treat relevant issues for successful translation of these encouraging preclinical results into treatments for patients with AD and PD.

  19. Quantitative phosphoproteomic analysis identifies activation of the RET and IGF-1R/IR signaling pathways in neuroblastoma.

    PubMed

    DeNardo, Bradley D; Holloway, Michael P; Ji, Qinqin; Nguyen, Kevin T; Cheng, Yan; Valentine, Marcus B; Salomon, Arthur; Altura, Rachel A

    2013-01-01

    Neuroblastoma is an embryonal tumor of childhood with a heterogenous clinical presentation that reflects differences in activation of complex biological signaling pathways. Protein phosphorylation is a key component of cellular signal transduction and plays a critical role in processes that control cancer cell growth and survival. We used shotgun LC/MS to compare phosphorylation between a human MYCN amplified neuroblastoma cell line (NB10), modeling a resistant tumor, and a human neural precursor cell line (NPC), modeling a normal baseline neural crest cell. 2181 unique phosphorylation sites representing 1171 proteins and 2598 phosphopeptides were found. Protein kinases accounted for 6% of the proteome, with a predominance of tyrosine kinases, supporting their prominent role in oncogenic signaling pathways. Highly abundant receptor tyrosine kinase (RTK) phosphopeptides in the NB10 cell line relative to the NPC cell line included RET, insulin-like growth factor 1 receptor/insulin receptor (IGF-1R/IR), and fibroblast growth factor receptor 1 (FGFR1). Multiple phosphorylated peptides from downstream mediators of the PI3K/AKT/mTOR and RAS pathways were also highly abundant in NB10 relative to NPC. Our analysis highlights the importance of RET, IGF-1R/IR and FGFR1 as RTKs in neuroblastoma and suggests a methodology that can be used to identify potential novel biological therapeutic targets. Furthermore, application of this previously unexploited technology in the clinic opens the possibility of providing a new wide-scale molecular signature to assess disease progression and prognosis.

  20. Inhibiting PPARγ by erythropoietin while upregulating TAZ by IGF1 synergistically promote osteogenic differentiation of mesenchymal stem cells.

    PubMed

    Zhou, Jianwei; Wei, Fangyuan; Ma, Yuquan

    2016-09-09

    Erythropoietin (EPO) is reported to promote osteogenesis and inhibit adipogenesis of mesenchymal stem cells (MSC) through inhibiting PPARγ, while insulin-like growth factor 1 (IGF1) is able to enhance osteogenesis via upregulating transcriptional coactivator with PDZ-binding motif (TAZ). The different targets of EPO and IGF1 suggested their potential synergism to enhance osteogenesis. In this study, we aimed to determine the potential synergism of EPO and IGF1 and its efficacy on MSC differentiation. Rat adipose-derived mesenchymal stem cells (ADSCs) were separately treated with EPO, IGF1 and EPO/IGF1. It was observed that the co-treatment using EPO and IGF1 was able to potently promote the osteogenic differentiation of rat ADSCs compared with EPO or IGF1 alone, which offered a promising effective option to strengthen bone tissue regeneration for bone defects. Further, we demonstrated that the enhanced osteogenic differentiation by EPO and IGF1 co-treatment was almost counteracted by activating PPARγ through PPARγ agonist, RSG, and blocking TAZ through TAZ silencing RNA, siTAZ. Thus, it could be concluded that EPO and IGF1 possessed a potent synergism in promoting osteogenic differentiation, and the synergism was mainly attributed to co-regulation of different osteogenic regulators PPARγ and TAZ, which were targeted genes of EPO and IGF1 respectively.

  1. Intrauterine Growth Retardation (IUGR) as a Novel Condition of Insulin-Like Growth Factor-1 (IGF-1) Deficiency.

    PubMed

    Martín-Estal, I; de la Garza, R G; Castilla-Cortázar, I

    2016-01-01

    Insulin-like growth factor 1 (IGF-1) is an anabolic hormone with several biological activities, such as proliferation, mitochondrial protection, cell survival, tissue growth and development, anti-inflammatory, antioxidant, antifibrogenic and antiaging. This hormone plays an important role in embryological and postnatal states, being essential for normal foetal and placental growth and differentiation. During gestation, the placenta is one of the major sources of IGF-1, among other hormones. This intrauterine organ expresses IGF-1 receptors and IGF-1 binding proteins (IGFBPs), which control IGF-1 activities. Intrauterine growth restriction (IUGR) is the second most frequent cause of perinatal morbidity and mortality, defined as the inability to achieve the expected weight for gestational age. Different studies have revealed that IUGR infants have placental dysfunction and low circulating levels of insulin, IGF-1, IGF-2 and IGFBPs. Such data suggest that IGF-1 deficiency in gestational state may be one of the major causes of foetal growth retardation. The aim of this review is to study the epidemiology, physiopathology and possible causes of IUGR. Also, it intends to study the possible role of the placenta as an IGF-1 target organ. The purpose is to establish if IUGR could be considered as a novel condition of IGF-1 deficiency and if its treatment with low doses of IGF-1 could be a suitable therapeutic strategy.

  2. Light stimuli control neuronal migration by altering of insulin-like growth factor 1 (IGF-1) signaling.

    PubMed

    Li, Ying; Komuro, Yutaro; Fahrion, Jennifer K; Hu, Taofang; Ohno, Nobuhiko; Fenner, Kathleen B; Wooton, Jessica; Raoult, Emilie; Galas, Ludovic; Vaudry, David; Komuro, Hitoshi

    2012-02-14

    The role of genetic inheritance in brain development has been well characterized, but little is known about the contributions of natural environmental stimuli, such as the effect of light-dark cycles, to brain development. In this study, we determined the role of light stimuli in neuronal cell migration to elucidate how environmental factors regulate brain development. We show that in early postnatal mouse cerebella, granule cell migration accelerates during light cycles and decelerates during dark cycles. Furthermore, cerebellar levels of insulin-like growth factor 1 (IGF-1) are high during light cycles and low during dark cycles. There are causal relationships between light-dark cycles, speed of granule cell migration, and cerebellar IGF-1 levels. First, changes in light-dark cycles result in corresponding changes in the fluctuations of both speed of granule cell migration and cerebellar IGF-1 levels. Second, in vitro studies indicate that exogenous IGF-1 accelerates the migration of isolated granule cells through the activation of IGF-1 receptors. Third, in vivo studies reveal that inhibiting the IGF-1 receptors decelerates granule cell migration during light cycles (high IGF-1 levels) but does not alter migration during dark cycles (low IGF-1 levels). In contrast, stimulating the IGF-1 receptors accelerates granule cell migration during dark cycles (low IGF-1 levels) but does not alter migration during light cycles (high IGF-1 levels). These results suggest that during early postnatal development light stimuli control granule cell migration by altering the activity of IGF-1 receptors through modification of cerebellar IGF-1 levels.

  3. Light stimuli control neuronal migration by altering of insulin-like growth factor 1 (IGF-1) signaling

    PubMed Central

    Li, Ying; Komuro, Yutaro; Fahrion, Jennifer K.; Hu, Taofang; Ohno, Nobuhiko; Fenner, Kathleen B.; Wooton, Jessica; Raoult, Emilie; Galas, Ludovic; Vaudry, David; Komuro, Hitoshi

    2012-01-01

    The role of genetic inheritance in brain development has been well characterized, but little is known about the contributions of natural environmental stimuli, such as the effect of light–dark cycles, to brain development. In this study, we determined the role of light stimuli in neuronal cell migration to elucidate how environmental factors regulate brain development. We show that in early postnatal mouse cerebella, granule cell migration accelerates during light cycles and decelerates during dark cycles. Furthermore, cerebellar levels of insulin-like growth factor 1 (IGF-1) are high during light cycles and low during dark cycles. There are causal relationships between light–dark cycles, speed of granule cell migration, and cerebellar IGF-1 levels. First, changes in light–dark cycles result in corresponding changes in the fluctuations of both speed of granule cell migration and cerebellar IGF-1 levels. Second, in vitro studies indicate that exogenous IGF-1 accelerates the migration of isolated granule cells through the activation of IGF-1 receptors. Third, in vivo studies reveal that inhibiting the IGF-1 receptors decelerates granule cell migration during light cycles (high IGF-1 levels) but does not alter migration during dark cycles (low IGF-1 levels). In contrast, stimulating the IGF-1 receptors accelerates granule cell migration during dark cycles (low IGF-1 levels) but does not alter migration during light cycles (high IGF-1 levels). These results suggest that during early postnatal development light stimuli control granule cell migration by altering the activity of IGF-1 receptors through modification of cerebellar IGF-1 levels. PMID:22308338

  4. Targeting the IGF-1R: The Tale of the Tortoise and the Hare

    PubMed Central

    Crudden, Caitrin; Girnita, Ada; Girnita, Leonard

    2015-01-01

    The insulin-like growth factor type 1 receptor (IGF-1R) plays a key role in the development and maintenance of cancer. Since the first links between growth factor receptors and oncogenes were noted over three decades ago, targeting the IGF-1R has been of great interest. This review follows the progress from inception through intense pharmaceutical development, disappointing clinical trials and recent updates to the signaling paradigm. In light of major developments in signaling understanding and activation complexities, we examine reasons for failure of first line targeting approaches. Recent findings include the fact that the IGF-1R can signal in the absence of the ligand, in the absence of kinase activity, and utilizes components of the GPCR system. With recognition of the unappreciated complexities that this first wave of targeting approaches encountered, we advocate re-recognition of IGF-1R as a valid target for cancer treatment and look to future directions, where both research and pharmaceutical strengths can lend themselves to finally unearthing anti-IGF-1R potential. PMID:25964779

  5. IGF1R levels in the brain negatively correlate with longevity in 16 rodent species.

    PubMed

    Azpurua, Jorge; Yang, Jiang-Nan; Van Meter, Michael; Liu, Zhengshan; Kim, Julie; Lobo Ladd, Aliny A B; Coppi, Antonio Augusto; Gorbunova, Vera; Seluanov, Andrei

    2013-04-01

    The insulin/insulin-like growth factor signaling (IIS) pathway is a major conserved regulator of aging. Nematode, fruit fly and mouse mutants with reduced IIS signaling exhibit extended lifespan. These mutants are often dwarfs leading to the idea that small body mass correlates with longevity within species. However, when different species are compared, larger animals are typically longer-lived. Hence, the role of IIS in the evolution of life history traits remains unresolved. Here we used comparative approach to test whether IGF1R signaling changes in response to selection on lifespan or body mass and whether specific tissues are involved. The IGF1R levels in the heart, lungs, kidneys, and brains of sixteen rodent species with highly diverse lifespans and body masses were measured via immunoblot after epitope conservation analysis. We report that IGF1R levels display strong negative correlation with maximum lifespan only in brain tissue and no significant correlations with body mass for any organ. The brain-IGF1R and lifespan correlation holds when phylogenetic non-independence of data-points is taken into account. These results suggest that modulation of IGF1R signaling in nervous tissue, but not in the peripheral tissues, is an important factor in the evolution of longevity in mammals.

  6. miR-126 contributes to Parkinson disease by dysregulating IGF-1/PI3K signaling

    PubMed Central

    Kim, Woori; Lee, Yenarae; McKenna, Noah D.; Yi, Ming; Simunovic, Filip; Wang, Yulei; Kong, Benjamin; Rooney, Robert J.; Seo, Hyemyung; Stephens, Robert; Sonntag, Kai C.

    2014-01-01

    Dopamine (DA) neurons in sporadic Parkinson disease (PD) display dysregulated gene expression networks and signaling pathways that are implicated in PD pathogenesis. Micro (mi)RNAs are regulators of gene expression, which could be involved in neurodegenerative diseases. We determined the miRNA profiles in laser microdissected DA neurons from postmortem sporadic PD patients’ brains and age-matched controls. DA neurons had a distinctive miRNA signature and a set of miRNAs was dysregulated in PD. Bioinformatics analysis provided evidence for correlations of miRNAs with signaling pathways relevant to PD, including an association of miR-126 with insulin/IGF-1/PI3K signaling. In DA neuronal cell systems, enhanced expression of miR-126 impaired IGF-1 signaling and increased vulnerability to the neurotoxin 6-OHDA by downregulating factors in IGF-1/PI3K signaling, including its targets p85β, IRS-1, and SPRED1. Blocking of miR-126 function increased IGF-1 trophism and neuroprotection to 6-OHDA. Our data imply that elevated levels of miR-126 may play a functional role in DA neurons and in PD pathogenesis by downregulating IGF-1/PI3K/AKT signaling and that its inhibition could be a mechanism of neuroprotection. PMID:24559646

  7. Role of IGF1R in Breast Cancer Subtypes, Stemness, and Lineage Differentiation

    PubMed Central

    Farabaugh, Susan M.; Boone, David N.; Lee, Adrian V.

    2015-01-01

    Insulin-like growth factor (IGF) signaling is fundamental for growth and survival. A large body of evidence (laboratory, epidemiological, and clinical) implicates the exploitation of this pathway in cancer. Up to 50% of breast tumors express the activated form of the type 1 insulin-like growth factor receptor (IGF1R). Breast cancers are categorized into subtypes based upon hormone and ERRB2 receptor expression and/or gene expression profiling. Even though IGF1R influences tumorigenic phenotypes and drug resistance across all breast cancer subtypes, it has specific expression and function in each. In some subtypes, IGF1R levels correlate with a favorable prognosis, while in others it is associated with recurrence and poor prognosis, suggesting different actions based upon cellular and molecular contexts. In this review, we examine IGF1R expression and function as it relates to breast cancer subtype and therapy-acquired resistance. Additionally, we discuss the role of IGF1R in stem cell maintenance and lineage differentiation and how these cell fate influences may alter the differentiation potential and cellular composition of breast tumors. PMID:25964777

  8. MicroRNA-486-5p enhances hepatocellular carcinoma tumor suppression through repression of IGF-1R and its downstream mTOR, STAT3 and c-Myc

    PubMed Central

    Youness, Rana Ahmed; El-Tayebi, Hend Mohamed; Assal, Reem Amr; Hosny, Karim; Esmat, Gamal; Abdelaziz, Ahmed Ihab

    2016-01-01

    The insulin-like growth factor (IGF)-axis has been paradigmatically involved in hepatocellular carcinoma (HCC) tumor initiation, progression and drug resistance. Consequently, members of the IGF-axis and most importantly, IGF-1 receptor (IGF-1R) have been considered as intriguing targets for HCC therapy. Few miRNAs have been recently reported to be associated with IGF-1R regulation. The present study aimed to investigate the role of microRNA (miRNA/miR)-486-5p in the regulation of IGF-1R and its downstream signaling cascades. miR-486-5p was markedly downregulated in hepatitis C virus-induced HCC tissues and Huh-7 cells. Forcing the expression of miR-486-5p in Huh-7 cells resulted in the repression of IGF-1R, mammalian target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3) and c-Myc mRNA levels. Ectopic expression of miR-486-5p in Huh-7 cells markedly repressed cellular viability, proliferation, migration and clonogenicity in a similar pattern to IGF-1R small interfering RNAs, and were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, BrdU incorporation, wound healing and colony forming assays, respectively. Overall, the study findings demonstrated that miR-486-5p acts as a tumor suppressor in HCC through the repression of essential members of the IGF-axis, including IGF-1R and its downstream mediators mTOR, STAT3 and c-Myc. PMID:27698829

  9. IGF-1, the Cross Road of the Nutritional, Inflammatory and Hormonal Pathways to Frailty

    PubMed Central

    Maggio, Marcello; De Vita, Francesca; Lauretani, Fulvio; Buttò, Valeria; Bondi, Giuliana; Cattabiani, Chiara; Nouvenne, Antonio; Meschi, Tiziana; Dall’Aglio, Elisabetta; Ceda, Gian Paolo

    2013-01-01

    The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects. PMID:24152751

  10. The IGF-1/cortisol ratio as a useful marker for monitoring training in young boxers.

    PubMed

    Nassib, S; Moalla, W; Hammoudi-Nassib, S; Chtara, M; Hachana, Y; Tabka, Z; Chamari, K; Elloumi, M

    2016-03-01

    Training effects on plasma insulin-like growth factor-1 (IGF-1)/cortisol ratio were investigated in boxers. Thirty subjects were assigned to either the training or the control group (n = 15 in both). They were tested before the beginning of training (T0), after 5 weeks of intensive training (T1), and after 1 week of tapering (T2). Physical performances (Yo-Yo intermittent recovery test level-1), training loads, and blood sampling were obtained at T0, T1, and T2. Controls were only tested for biochemical and anthropometric parameters at T0 and T2. A significantly higher physical performance was observed at T2 compared to T1. At T1, cortisol levels were significantly increased whereas IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels remained unchanged compared to baseline. At T2, cortisol levels decreased while IGF-1 and IGFBP-3 levels increased. The IGF-1/cortisol ratio decreased significantly at T1 and increased at T2, and its variations were significantly correlated with changes in training loads and Yo-Yo intermittent recovery test level 1 (IRT1) performance over the training period. Cortisol variations correlated with changes in training load (r = 0.64; p < 0.01) and Yo-Yo IRT1 performance (r = 0.78; p < 0.001) at T1 whereas IGF-1 variations correlated only with changes in Yo-Yo IRT1 performance at T2 (r = 0.71; p < 0.001). It is concluded that IGF-1/cortisol ratio could be a useful tool for monitoring training loads in young trained boxers.

  11. The IGF-1/cortisol ratio as a useful marker for monitoring training in young boxers

    PubMed Central

    Nassib, S; Moalla, W; Hammoudi-Nassib, S; Chtara, M; Hachana, Y; Tabka, Z; Chamari, K

    2015-01-01

    Training effects on plasma insulin-like growth factor-1 (IGF-1)/cortisol ratio were investigated in boxers. Thirty subjects were assigned to either the training or the control group (n = 15 in both). They were tested before the beginning of training (T0), after 5 weeks of intensive training (T1), and after 1 week of tapering (T2). Physical performances (Yo-Yo intermittent recovery test level-1), training loads, and blood sampling were obtained at T0, T1, and T2. Controls were only tested for biochemical and anthropometric parameters at T0 and T2. A significantly higher physical performance was observed at T2 compared to T1. At T1, cortisol levels were significantly increased whereas IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels remained unchanged compared to baseline. At T2, cortisol levels decreased while IGF-1 and IGFBP-3 levels increased. The IGF-1/cortisol ratio decreased significantly at T1 and increased at T2, and its variations were significantly correlated with changes in training loads and Yo-Yo intermittent recovery test level 1 (IRT1) performance over the training period. Cortisol variations correlated with changes in training load (r = 0.64; p < 0.01) and Yo-Yo IRT1 performance (r = 0.78; p < 0.001) at T1 whereas IGF-1 variations correlated only with changes in Yo-Yo IRT1 performance at T2 (r = 0.71; p < 0.001). It is concluded that IGF-1/cortisol ratio could be a useful tool for monitoring training loads in young trained boxers. PMID:26985129

  12. IGF-1R inhibition in mammary epithelia promotes canonical Wnt signaling and Wnt1-driven tumors

    PubMed Central

    Rota, Lauren M.; Albanito, Lidia; Shin, Marcus E.; Goyeneche, Corey L.; Shushanov, Sain; Gallagher, Emily J.; LeRoith, Derek; Lazzarino, Deborah A.; Wood, Teresa L.

    2014-01-01

    Triple-negative breast cancers (TNBC) are an aggressive disease subtype which unlike other subtypes lack an effective targeted therapy. Inhibitors of the insullin-like growth factor receptor (IGF-1R) have been considered for use in treating TNBC. Here we provide genetic evidence that IGF-1R inhibition promotes development of Wnt1-mediated murine mammary tumors that offer a model of TNBC. We found that in a double transgenic mouse model carrying activated Wnt-1 and mutant IGF-1R, a reduction in IGF-1R signaling reduced tumor latency and promoted more aggressive phenotypes. These tumors displayed a squamal cell phenotype with increased expression of keratins 5/6 and β-catenin. Notably, cell lineage analyses revealed an increase in basal (CD29hi/CD24+) and luminal (CD24+/CD61+/CD29lo) progenitor cell populations, along with increased Nanog expression and decreased Elf5 expression. In these doubly transgenic mice, lung metastases developed with characteristics of the primary tumors, unlike MMTV-Wnt1 mice. Mechanistic investigations showed that pharmacological inhibition of the IGF-1R in vitro was sufficient to increase the tumorsphere-forming efficiency of MMTV-Wnt1 tumor cells. Tumors from doubly transgenic mice also exhibited an increase in the expression ratio of the IGF-II-sensitive, A isoform of the insulin receptor vs the IR-B isoform, which in vitro resulted in enhanced expression of β-catenin. Overall, our results revealed that in Wnt-driven tumors an attenuation of IGF-1R signaling accelerates tumorigenesis and promotes more aggressive phenotypes, with potential implications for understanding TNBC pathobiology and treatment. PMID:25092896

  13. IGF-1R inhibition sensitizes breast cancer cells to ATM-related kinase (ATR) inhibitor and cisplatin

    PubMed Central

    O'Flanagan, Ciara H.; O'shea, Sandra; Lyons, Amy; Fogarty, Fionola M.; McCabe, Nuala; Kennedy, Richard D.; O'Connor, Rosemary

    2016-01-01

    The complexity of the IGF-1 signalling axis is clearly a roadblock in targeting this receptor in cancer therapy. Here, we sought to identify mediators of resistance, and potential co-targets for IGF-1R inhibition. By using an siRNA functional screen with the IGF-1R tyrosine kinase inhibitor (TKI) BMS-754807 in MCF-7 cells we identified several genes encoding components of the DNA damage response (DDR) pathways as mediators of resistance to IGF-1R kinase inhibition. These included ATM and Ataxia Telangiectasia and RAD3-related kinase (ATR). We also observed a clear induction of DDR in cells that were exposed to IGF-1R TKIs (BMS-754807 and OSI-906) as indicated by accumulation of γ-H2AX, and phosphorylated Chk1. Combination of the IGF-1R/IR TKIs with an ATR kinase inhibitor VE-821 resulted in additive to synergistic cytotoxicity compared to either drug alone. In MCF-7 cells with stably acquired resistance to the IGF-1R TKI (MCF-7-R), DNA damage was also observed, and again, dual inhibition of the ATR kinase and IGF-1R/IR kinase resulted in synergistic cytotoxicity. Interestingly, dual inhibition of ATR and IGF-1R was more effective in MCF-7-R cells than parental cells. IGF-1R TKIs also potentiated the effects of cisplatin in a panel of breast cancer cell lines. Overall, our findings identify induction of DDR by IGF-1R kinase inhibition as a rationale for co-targeting the IGF-1R with ATR kinase inhibitors or cisplatin, particularly in cells with acquired resistance to TKIs. PMID:27472395

  14. Nutritional modulation of IGF-1 in relation to growth and body condition in Sceloporus lizards.

    PubMed

    Duncan, Christine A; Jetzt, Amanda E; Cohick, Wendie S; John-Alder, Henry B

    2015-05-15

    Nutrition and energy balance are important regulators of growth and the growth hormone/insulin-like growth factor (GH/IGF) axis. However, our understanding of these functions does not extend uniformly to all classes of vertebrates and is mainly limited to controlled laboratory conditions. Lizards can be useful models to improve our understanding of the nutritional regulation of the GH/IGF-1 axis because many species are relatively easy to observe and manipulate both in the laboratory and in the field. In the present study, the effects of variation in food intake on growth, body condition, and hepatic IGF-1 mRNA levels were measured in (1) juveniles of Sceloporus jarrovii maintained on a full or 1/3 ration and (2) hatchlings of Sceloporus undulatus subjected to full or zero ration with or without re-feeding. These parameters plus plasma IGF-1 were measured in a third experiment using adults of S. undulatus subjected to full or zero ration with or without re-feeding. In all experiments, plasma corticosterone was measured as an anticipated indicator of nutritional stress. In S. jarrovii, growth and body condition were reduced but lizards remained in positive energy balance on 1/3 ration, and hepatic IGF-1 mRNA and plasma corticosterone were not affected in comparison to full ration. In S. undulatus, growth, body condition, hepatic IGF-1 mRNA, and plasma IGF-1 were all reduced by zero ration and restored by refeeding. Plasma corticosterone was increased in response to zero ration and restored by full ration in hatchlings but not adults of S. undulatus. These data indicate that lizards conform to the broader vertebrate model in which severe food deprivation and negative energy balance is required to attenuate systemic IGF-1 expression. However, when animals remain in positive energy balance, reduced food intake does not appear to affect systemic IGF-1. Consistent with other studies on lizards, the corticosterone response to reduced food intake is an unreliable indicator

  15. Dauer-independent insulin/IGF-1-signalling implicates collagen remodelling in longevity.

    PubMed

    Ewald, Collin Y; Landis, Jess N; Porter Abate, Jess; Murphy, Coleen T; Blackwell, T Keith

    2015-03-05

    Interventions that delay ageing mobilize mechanisms that protect and repair cellular components, but it is unknown how these interventions might slow the functional decline of extracellular matrices, which are also damaged during ageing. Reduced insulin/IGF-1 signalling (rIIS) extends lifespan across the evolutionary spectrum, and in juvenile Caenorhabditis elegans also allows the transcription factor DAF-16/FOXO to induce development into dauer, a diapause that withstands harsh conditions. It has been suggested that rIIS delays C. elegans ageing through activation of dauer-related processes during adulthood, but some rIIS conditions confer robust lifespan extension unaccompanied by any dauer-like traits. Here we show that rIIS can promote C. elegans longevity through a program that is genetically distinct from the dauer pathway, and requires the Nrf (NF-E2-related factor) orthologue SKN-1 acting in parallel to DAF-16. SKN-1 is inhibited by IIS and has been broadly implicated in longevity, but is rendered dispensable for rIIS lifespan extension by even mild activity of dauer-related processes. When IIS is decreased under conditions that do not induce dauer traits, SKN-1 most prominently increases expression of collagens and other extracellular matrix genes. Diverse genetic, nutritional, and pharmacological pro-longevity interventions delay an age-related decline in collagen expression. These collagens mediate adulthood extracellular matrix remodelling, and are needed for ageing to be delayed by interventions that do not involve dauer traits. By genetically delineating a dauer-independent rIIS ageing pathway, our results show that IIS controls a broad set of protective mechanisms during C. elegans adulthood, and may facilitate elucidation of processes of general importance for longevity. The importance of collagen production in diverse anti-ageing interventions implies that extracellular matrix remodelling is a generally essential signature of longevity assurance

  16. All-atom structural models for complexes of insulin-like growth factors IGF1 and IGF2 with their cognate receptor.

    PubMed

    Vashisth, Harish; Abrams, Cameron F

    2010-07-16

    Type 1 insulin-like growth factor receptor (IGF1R) is a membrane-spanning glycoprotein of the insulin receptor family that has been implicated in a variety of cancers. The key questions related to molecular mechanisms governing ligand recognition by IGF1R remain unanswered, partly due to the lack of testable structural models of apo or ligand-bound receptor complexes. Using a homology model of the IGF1R ectodomain IGF1RDeltabeta, we present the first experimentally consistent all-atom structural models of IGF1/IGF1RDeltabeta and IGF2/IGF1RDeltabeta complexes. Our explicit-solvent molecular dynamics (MD) simulation of apo-IGF1RDeltabeta shows that it displays asymmetric flexibility mechanisms that result in one of two binding pockets accessible to growth factors IGF1 and IGF2, as demonstrated via an MD-assisted Monte Carlo docking procedure. Our MD-generated ensemble of structures of apo and IGF1-bound IGF1RDeltabeta agrees reasonably well with published small-angle X-ray scattering data. We observe simultaneous contacts of each growth factor with sites 1 and 2 of IGF1R, suggesting cross-linking of receptor subunits. Our models provide direct evidence in favor of suggested electrostatic complementarity between the C-domain (IGF1) and the cysteine-rich domain (IGF1R). Our IGF1/IGF1RDeltabeta model provides structural bases for the observation that a single IGF1 molecule binds to IGF1RDeltabeta at low concentrations in small-angle X-ray scattering studies. We also suggest new possible structural bases for differences in the affinities of insulin, IGF1, and IGF2 for their noncognate receptors.

  17. A 90-day safety study of genetically modified rice expressing rhIGF-1 protein in C57BL/6J rats.

    PubMed

    Tang, Maoxue; Xie, Tingting; Cheng, Wenke; Qian, Lili; Yang, Shulin; Yang, Daichang; Cui, Wentao; Li, Kui

    2012-06-01

    Genetically modified plants expressing disease resistance traits offer new treatment strategies for human diseases, but at the same time present a challenge in terms of food safety assessment. The present 90-day feeding study was designed to assess the safety of transgenic rice expressing the recombinant human insulin-like growth factor-1 (rhIGF-1) compared to its parental wild rice. Male and female C57BL/6J rats were given a nutritionally balanced purified diet with 20% transgenic rhIGF-1 rice or 20% parental rice for 90 days. This corresponds to a mean daily rhIGF-1 protein intake of approximately 217.6 mg/kg body weight based on the average feed consumption. In the animal study a range of biological, biochemical, clinical, microbiological and pathological parameters were examined and several significant differences were observed between groups, but none of the effects were considered to be adverse. In conclusion, no adverse or toxic effects on C57BL/6J rats were observed in the design used in this 90-day study. These results will provide valuable information for the safety assessment of genetically modified food crops.

  18. Circulating IGF-1 may mediate improvements in haemoglobin associated with vitamin A status during pregnancy in rural Nepalese women.

    PubMed

    Arguello, Margia A; Schulze, Kerry J; Wu, Lee Sf; Dreyfuss, Michele L; Khatry, Subarna K; Christian, Parul; West, Keith P

    2015-01-01

    Pregnancy exacerbates vitamin A (VA) deficiency and anaemia among women in developing countries. Improving circulating haemoglobin (Hb) requires erythrocyte production and availability of iron. Insulin-like growth factor- 1 (IGF-1) functions in erythropoiesis, but its association with VA status and pregnancy-associated anaemia has not been studied. The aim of this study was to examine the relationship between serum retinol, IGF-1, and Hb among pregnant women in extant samples collected during a placebo-controlled trial of VA and beta-carotene (BC) supplementation in rural Nepal conducted from 1994 to 1997. Mid-pregnancy serum IGF-1 was measured in serum from n=589 randomly selected women of n=1186 in whom anthropometric, VA (retinol) and iron (Hb, erythrocyte zinc protoporphyrin (ZP), and ferritin) status data were available. Associations of IGF-1 with retinol, Hb or anaemia, and iron status were determined using multiple linear and logistic regression. Path analysis was used to explore the role of IGF-1 as a mediator between retinol and Hb, accounting for iron status. A 2.6 g/L increase in IGF-1 was observed per 0.1 mol/L increment in retinol (p<0.0001). Hb increased with each quartile of IGF-1, and odds of anaemia declined 68.8% from the 1st to 4th quartile. Improved iron status indicators explained only 29.1% of the association between IGF-1 and Hb, while IGF-1 explained 25.6% of the association between retinol and Hb. Increasing IGF-1 was likely one mechanism by which retinol improved circulating Hb in pregnant women of rural Nepal, although IGF-1 worked primarily through pathways independent of improved iron status indicators, perhaps by stimulating erythrocyte production.

  19. Bioavailable IGF-1 and its Relation to the Metabolic Syndrome in a Bi-Ethnic Population of Men and Women.

    PubMed

    Koegelenberg, A S E; Schutte, R; Smith, W; Schutte, A E

    2016-02-01

    Insulin-like growth factor 1 (IGF-1), an insulin sensitivity and vasculoprotective factor, associates negatively with the metabolic syndrome. However, IGF-1 is reduced by factors such as inflammation, oxidative stress and liver dysfunction. We investigated the relationship between bioavailable IGF-1 and the number of metabolic syndrome components and determined whether this relationship is independent of inflammation, oxidative stress and gamma glutamyl transferase (γ-GT; a marker of liver dysfunction). This study included 907 black and white participants stratified by sex (aged 43.0±11.8 years). Among them 63 participants had fasting glucose levels of ≥+7.0+mmol/l and/or used diabetes medication. Via standard methods we determined waist circumference, fasting glucose, triglycerides, high-density lipoprotein cholesterol and blood pressure. We also determined high-sensitivity C-reactive protein (CRP), reactive oxygen species (ROS), γ-GT, IGF-1 and insulin-like growth factor binding protein 3 (IGFBP-3). IGF-1/IGFBP-3 was used as an estimate of bioavailable IGF-1. Total IGF-1 was similar between men and women (p=0.10), however, bioavailable IGF-1 was lower in women (p<0.001). In multivariate-adjusted analyses, IGF-1/IGFBP-3 was inversely associated with the number of metabolic syndrome components in both sexes (men: β=- 0.11; p=0.013 and women: β=- 0.17; p=0.003). Upon inclusion of ROS, γ-GT and CRP, significance was lost. In patients without diabetes, the results for men changed marginally, but were consistent for women. We found an inverse association between bioavailable IGF-1 and the number of metabolic syndrome components. But the relationship was dependent on oxidative stress, liver dysfunction and inflammation, suggesting underlying processes by which the metabolic syndrome attenuates IGF-1.

  20. IGF-1 Release Kinetics from Chitosan Microparticles Fabricated Using Environmentally Benign Conditions

    PubMed Central

    Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

    2014-01-01

    The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p<0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with Von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx 2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. PMID:25063148

  1. Targeting Extracellular DNA to Deliver IGF-1 to the Injured Heart

    NASA Astrophysics Data System (ADS)

    Khan, Raffay S.; Martinez, Mario D.; Sy, Jay C.; Pendergrass, Karl D.; Che, Pao-Lin; Brown, Milton E.; Cabigas, E. Bernadette; Dasari, Madhuri; Murthy, Niren; Davis, Michael E.

    2014-03-01

    There is a great need for the development of therapeutic strategies that can target biomolecules to damaged myocardium. Necrosis of myocardium during a myocardial infarction (MI) is characterized by extracellular release of DNA, which can serve as a potential target for ischemic tissue. Hoechst, a histological stain that binds to double-stranded DNA can be conjugated to a variety of molecules. Insulin-like growth factor-1 (IGF-1), a small protein/polypeptide with a short circulating-half life is cardioprotective following MI but its clinical use is limited by poor delivery, as intra-myocardial injections have poor retention and chronic systemic presence has adverse side effects. Here, we present a novel delivery vehicle for IGF-1, via its conjugation to Hoechst for targeting infarcted tissue. Using a mouse model of ischemia-reperfusion, we demonstrate that intravenous delivery of Hoechst-IGF-1 results in activation of Akt, a downstream target of IGF-1 and protects from cardiac fibrosis and dysfunction following MI.

  2. The effects of IGF1 on the melanogenesis in alpaca melanocytes in vitro.

    PubMed

    Hu, Shuaipeng; Liu, Yu; Yang, Shanshan; Ji, Kaiyuan; Liu, Xuexian; Zhang, Junzhen; Fan, Ruiwen; Dong, Changsheng

    2016-09-01

    In order to investigate the effects of the insulin-like growth factor 1(IGF-1) on alpaca melanocyte in vitro, different dosees of IGF1 (0, 10, 20, 40 ng/ml) were added in the medium of alpaca melanocyte. The RTCA machine was used to monitor the proliferation, quantitative real-time PCR, and western blot to test the relative gene expression, ELISA to test cAMP production, and spectrum method to test the melanin production. The results showed that compared to the normal melanocyte, the proliferation of melanocytes was increased within 60 h following adding IGF1. It also showed that cAMP content produced by melanocytes was increased, microphthalmia-associtated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein 2 (TYRP2) expression was increased, and melanin production with most obvious change in 10 ng/ml supplementary group, when compared with the control group. The results suggested that IGF1 with the dose of 10 ng/ml had the important effects on the melanogenesis in alpaca melanocyte by the cAMP pathway.

  3. Protein kinase C beta II suppresses colorectal cancer by regulating IGF-1 mediated cell survival

    PubMed Central

    Dowling, Catríona M.; Phelan, James; Callender, Julia A.; Cathcart, Mary Clare; Mehigan, Brian; McCormick, Paul; Dalton, Tara; Coffey, John C.; Newton, Alexandra C.; O'sullivan, Jacintha; Kiely, Patrick A.

    2016-01-01

    Despite extensive efforts, cancer therapies directed at the Protein Kinase C (PKC) family of serine/threonine kinases have failed in clinical trials. These therapies have been directed at inhibiting PKC and have, in some cases, worsened disease outcome. Here we examine colon cancer patients and show not only that PKC Beta II is a tumour suppressor, but patients with low levels of this isozyme have significantly decreased disease free survival. Specifically, analysis of gene expression levels of all PKC genes in matched normal and cancer tissue samples from colon cancer patients revealed a striking down-regulation of the gene coding PKC Beta in the cancer tissue (n = 21). Tissue microarray analysis revealed a dramatic down-regulation of PKC Beta II protein levels in both the epithelial and stromal diseased tissue (n = 166). Of clinical significance, low levels of the protein in the normal tissue of patients is associated with a low (10%) 10 year survival compared with a much higher (60%) survival in patients with relatively high levels of the protein. Consistent with PKC Beta II levels protecting against colon cancer, overexpression of PKC Beta II in colon cancer cell lines reveals that PKC Beta II reverses transformation in cell based assays. Further to this, activation of PKC Beta II results in a dramatic downregulation of IGF-I-induced AKT, indicating a role for PKCs in regulating IGF-1 mediated cell survival. Thus, PKC Beta II is a tumour suppressor in colon cancer and low levels serve as a predictor for poor survival outcome. PMID:26989024

  4. The Association Between IGF-1 Levels and the Histologic Severity of Nonalcoholic Fatty Liver Disease

    PubMed Central

    Dichtel, Laura E; Corey, Kathleen E; Misdraji, Joseph; Bredella, Miriam A; Schorr, Melanie; Osganian, Stephanie A; Young, Brian J; Sung, Joshua C; Miller, Karen K

    2017-01-01

    Objectives: The mechanisms responsible for the development of nonalcoholic fatty liver disease (NAFLD) and progression to nonalcoholic steatohepatitis (NASH) are incompletely understood. Growing evidence suggests that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) may have roles in the development and progression of NAFLD. We hypothesized that lower serum IGF-1 levels would be associated with increased liver fat accumulation, inflammation, and fibrosis in a group of meticulously phenotyped obese subjects with liver biopsies. Methods: A retrospective, cross-sectional study was performed at Massachusetts General Hospital, Boston, MA, USA and St. Mary's Hospital, Richmond, VA, USA. Liver biopsies were performed in 142 subjects during NAFLD work-up or bariatric surgery and were graded by a single, blinded pathologist. Main outcome measures included liver histology and serum IGF-1. Results: Mean age was 52±10 years and body mass index (BMI) was 43±9 kg/m2. Mean serum IGF-1 was lower in subjects with lobular inflammation (112±47 vs. 136±57 ng/ml, P=0.01), hepatocyte ballooning (115±48 vs. 135±57 ng/ml, P=0.05), higher fibrosis stage (stage 2–4 vs. 0–1; 96±40 vs. 125±51 ng/ml, P=0.005), and NASH (109±45 vs. 136±57 ng/ml, P=0.002). All results remained significant after controlling for age, BMI, and a diagnosis of diabetes, and all but hepatocyte ballooning (trend, P=0.06) remained significant after excluding individuals with cirrhosis. Steatosis was not significantly associated with mean serum IGF-1 levels. Conclusions: Low serum IGF-1 levels are associated with increased histologic severity of NAFLD when rigorously controlled for age, BMI, the presence of diabetes, and after the exclusion of subjects with cirrhosis. Further investigation is warranted to determine the differential effects of GH and IGF-1 on the development and progression of NAFLD, which could further elucidate pathophysiology and identify therapeutic targets. PMID

  5. Durable Response of Spinal Chordoma to Combined Inhibition of IGF-1R and EGFR

    PubMed Central

    Aleksic, Tamara; Browning, Lisa; Woodward, Martha; Phillips, Rachel; Page, Suzanne; Henderson, Shirley; Athanasou, Nicholas; Ansorge, Olaf; Whitwell, Duncan; Pratap, Sarah; Hassan, A. Bassim; Middleton, Mark R.; Macaulay, Valentine M.

    2016-01-01

    Chordomas are rare primary malignant bone tumors arising from embryonal notochord remnants of the axial skeleton. Chordomas commonly recur following surgery and radiotherapy, and there is no effective systemic therapy. Previous studies implicated receptor tyrosine kinases, including epidermal growth factor receptor (EGFR) and type 1 insulin-like growth factor receptor (IGF-1R), in chordoma biology. We report an adult female patient who presented in 2003 with spinal chordoma, treated with surgery and radiotherapy. She underwent further surgery for recurrent chordoma in 2008, with subsequent progression in pelvic deposits. In June 2009, she was recruited onto the Phase I OSI-906-103 trial of EGFR inhibitor erlotinib with linsitinib, a novel inhibitor of IGF-1R/insulin receptor (INSR). Treatment with 100 mg QD erlotinib and 50 mg QD linsitinib was well-tolerated, and after 18 months a partial response was achieved by RECIST criteria. From 43 months, a protocol modification allowed intra-patient linsitinib dose escalation to 50 mg BID. The patient remained stable on trial treatment for a total of 5 years, discontinuing treatment in August 2014. She subsequently experienced further disease progression for which she underwent pelvic surgery in April 2015. Analysis of DNA extracted from 2008 (pre-trial) tissue showed that the tumor harbored wild-type EGFR, and a PIK3CA mutation was detected in plasma, but not tumor DNA. The 2015 (post-trial) tumor harbored a mutation of uncertain significance in ATM, with no detectable mutations in other components of a 50 gene panel, including EGFR, PIK3CA, and TP53. By immunohistochemistry, the tumor was positive for brachyury, the molecular hallmark of chordoma, and showed weak–moderate membrane and cytoplasmic EGFR. IGF-1R was detected in the plasma membrane and cytoplasm and was expressed more strongly in recurrent tumor than the primary. We also noted heterogeneous nuclear IGF-1R, which has been linked with sensitivity

  6. The complexity of the IGF1 gene splicing, posttranslational modification and bioactivity.

    PubMed

    Philippou, Anastassios; Maridaki, Maria; Pneumaticos, Spiros; Koutsilieris, Michael

    2014-05-07

    The insulinlike growth factor-I (IGF-I) is an important factor which regulates a variety of cellular responses in multiple biological systems. The IGF1 gene comprises a highly conserved sequence and contains six exons, which give rise to heterogeneous mRNA transcripts by a combination of multiple transcription initiation sites and alternative splicing. These multiple transcripts code for different precursor IGF-I polypeptides, namely the IGF-IEa, IGF-IEb and IGF-IEc isoforms in humans, which also undergo posttranslational modifications, such as proteolytic processing and glycosylation. IGF-I actions are mediated through its binding to several cell-membrane receptors and the IGF-I domain responsible for the receptor binding is the bioactive mature IGF-I peptide, which is derived after the posttranslational cleavage of the pro-IGF-I isoforms and the removal of their carboxy-terminal E-peptides (that is, the Ea, Eb and Ec). Interestingly, differential biological activities have been reported for the different IGF-I isoforms, or for their E-peptides, implying that IGF-I peptides other than the IGF-I ligand also possess bioactivity and, thus, both common and unique or complementary pathways exist for the IGF-I isoforms to promote biological effects. The multiple peptides derived from IGF-I and the differential expression of its various transcripts in different conditions and pathologies appear to be compatible with the distinct cellular responses observed to the different IGF-I peptides and with the concept of a complex and possibly isoform-specific IGF-I bioactivity. This concept is discussed in the present review, in the context of the broad range of modifications that this growth factor undergoes which might regulate its mechanism(s) of action.

  7. The Complexity of the IGF1 Gene Splicing, Posttranslational Modification and Bioactivity

    PubMed Central

    Philippou, Anastassios; Maridaki, Maria; Pneumaticos, Spiros; Koutsilieris, Michael

    2014-01-01

    The insulinlike growth factor-I (IGF-I) is an important factor which regulates a variety of cellular responses in multiple biological systems. The IGF1 gene comprises a highly conserved sequence and contains six exons, which give rise to heterogeneous mRNA transcripts by a combination of multiple transcription initiation sites and alternative splicing. These multiple transcripts code for different precursor IGF-I polypeptides, namely the IGF-IEa, IGF-IEb and IGF-IEc isoforms in humans, which also undergo posttranslational modifications, such as proteolytic processing and glycosylation. IGF-I actions are mediated through its binding to several cell-membrane receptors and the IGF-I domain responsible for the receptor binding is the bioactive mature IGF-I peptide, which is derived after the posttranslational cleavage of the pro-IGF-I isoforms and the removal of their carboxy-terminal E-peptides (that is, the Ea, Eb and Ec). Interestingly, differential biological activities have been reported for the different IGF-I isoforms, or for their E-peptides, implying that IGF-I peptides other than the IGF-I ligand also possess bioactivity and, thus, both common and unique or complementary pathways exist for the IGF-I isoforms to promote biological effects. The multiple peptides derived from IGF-I and the differential expression of its various transcripts in different conditions and pathologies appear to be compatible with the distinct cellular responses observed to the different IGF-I peptides and with the concept of a complex and possibly isoform-specific IGF-I bioactivity. This concept is discussed in the present review, in the context of the broad range of modifications that this growth factor undergoes which might regulate its mechanism(s) of action. PMID:24637928

  8. The PI3K/Akt/mTOR signaling pathway mediates insulin-like growth factor 1-induced E-cadherin down-regulation and cell proliferation in ovarian cancer cells.

    PubMed

    Lau, Man-Tat; Leung, Peter C K

    2012-12-30

    Insulin-like growth factor 1 (IGF1) is produced by ovarian cancer cells and it has been suggested that it plays an important role in tumor progression. In this study, we report that IGF1 treatment down-regulated E-cadherin by up-regulating E-cadherin transcriptional repressors, Snail and Slug, in human ovarian cancer cells. The pharmacological inhibition of phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) suggests that PI3K/Akt/mTOR signaling is required for IGF1-induced E-cadherin down-regulation. Moreover, IGF1 up-regulated Snail and Slug expression via the PI3K/Akt/mTOR signaling pathway. Finally, IGF1-induced cell proliferation was abolished by inhibiting PI3K/Akt/mTOR signaling. This study demonstrates a novel mechanism in which IGF1 down-regulates E-cadherin expression through the activation of PI3K/Akt/mTOR signaling and the up-regulation of Snail and Slug in human ovarian cancer cells.

  9. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population.

    PubMed

    Levine, Morgan E; Suarez, Jorge A; Brandhorst, Sebastian; Balasubramanian, Priya; Cheng, Chia-Wei; Madia, Federica; Fontana, Luigi; Mirisola, Mario G; Guevara-Aguirre, Jaime; Wan, Junxiang; Passarino, Giuseppe; Kennedy, Brian K; Wei, Min; Cohen, Pinchas; Crimmins, Eileen M; Longo, Valter D

    2014-03-04

    Mice and humans with growth hormone receptor/IGF-1 deficiencies display major reductions in age-related diseases. Because protein restriction reduces GHR-IGF-1 activity, we examined links between protein intake and mortality. Respondents aged 50-65 reporting high protein intake had a 75% increase in overall mortality and a 4-fold increase in cancer death risk during the following 18 years. These associations were either abolished or attenuated if the proteins were plant derived. Conversely, high protein intake was associated with reduced cancer and overall mortality in respondents over 65, but a 5-fold increase in diabetes mortality across all ages. Mouse studies confirmed the effect of high protein intake and GHR-IGF-1 signaling on the incidence and progression of breast and melanoma tumors, but also the detrimental effects of a low protein diet in the very old. These results suggest that low protein intake during middle age followed by moderate to high protein consumption in old adults may optimize healthspan and longevity.

  10. Microsatellite polymorphism in the P1 promoter region of the IGF-1 gene is associated with endometrial cancer

    PubMed Central

    KWASNIEWSKI, WOJCIECH; GOZDZICKA-JOZEFIAK, ANNA; WOLUN-CHOLEWA, MARIA; POLAK, GRZEGORZ; SIEROCINSKA-SAWA, JADWIGA; KWASNIEWSKA, ANNA; KOTARSKI, JAN

    2016-01-01

    Endometrial carcinoma (EC) is the most common type of gynecological malignancy. Studies have demonstrated that the insulin growth factor (IGF) pathway is implicated in the development of endometrial tumors and that the serum levels of IGF-1 are affected by estrogen. Most EC cells with high microsatellite instability (MSI-H) accumulate mutations at a microsatellite sequence in the IGF-1 gene. The present study investigated the CA repeat polymorphism in the P1 promoter region of the IGF-1 gene among Caucasian females with endometrial hyperplasia, EC and healthy control subjects, whose blood serum and surgical tissue specimens were analyzed. Differences or correlations between the analyzed parameters [serum levels of IGF-1 and IGF binding protein (IGFBP)-1 and IGFBP-3 as well as estrogens among the polymorphisms] were verified using the χ2, Mann-Whitney U, Kruskal-Wallis or Spearman's rank correlation tests. A PCR amplification and DNA sequencing analysis was used for identification of (CA)n repeats in the P1 region of IGF-1. ELISA was used to determine the blood serum levels of IGF-1, IGFBP-1, IGFBP-3 and estrogens. Furthermore, IGF-1 was assessed in endometrial tissues by immunohistochemical analysis. The present study indicated no statistically significant differences between serum levels of IGF-1, IGFBP-1, IGFBP-3 and estrone, estriol and estradiol in the control and study groups. A significant correlation was identified between the IGF-1 levels and estrone levels in the MSI-H polymorphism (r=−0.41, P=0.012) as well as a highly negative correlation between IGF-1 levels and the estradiol levels in the MSI-H polymorphism (r=−0.6, P=0.002). Genotypes without the 19 CA allele were predominantly found in EC. Furthermore, statistical analysis indicated that the number of IGF-1-expressing cells was significantly elevated in MSI-H type 18-20 (P= 0.0072), MSI-L type 19-20 (P=0.025) and microsatellite-stable MSS type 19-19 (P=0.024) compared with those in the MSI-H 20

  11. Higher TNF-α, IGF-1, and Leptin Levels are Found in Tasters than Non-Tasters

    PubMed Central

    Wang, Rui; van Keeken, Nika M. A.; Siddiqui, Sana; Dijksman, Lea M.; Maudsley, Stuart; Derval, Diana; van Dam, P. Sytze; Martin, Bronwen

    2014-01-01

    Taste perception is controlled by taste cells that are present in the tongue that produce and secrete various metabolic hormones. Recent studies have demonstrated that taste receptors in tongue, gut, and pancreas are associated with local hormone secretion. The aim of this study was to determine whether there is a link between taste sensitivity and levels of circulating metabolic hormones in humans and whether taste sensitivity is potentially related to peripheral metabolic regulation. Thirty-one subjects were recruited and separated into tasters and non-tasters based on their phenol thiocarbamide (PTC) bitter taste test results. Fasting plasma and saliva were collected and levels of hormones and cytokines were assayed. We observed significant differences in both hormone levels and hormone-body mass index (BMI) correlation between tasters and non-tasters. Tasters had higher plasma levels of leptin (p = 0.05), tumor necrosis factor-α (TNF-α) (p = 0.04), and insulin-like growth factor 1 (IGF-1) (p = 0.03). There was also a trend toward increased IGF-1 levels in the saliva of tasters (p = 0.06). We found a positive correlation between plasma levels of glucose and BMI (R = 0.4999, p = 0.04) exclusively in non-tasters. In contrast, plasma C-peptide levels were found to be positively correlated to BMI (R = 0.5563, p = 0.03) in tasters. Saliva TNF-α levels were negatively correlated with BMI in tasters (R = −0.5908, p = 0.03). Our findings demonstrate that there are differences in circulating levels of leptin, TNF-α, and IGF-1 between tasters and non-tasters. These findings indicate that in addition to the regulation of food consumption, taste perception also appears to be tightly linked to circulating metabolic hormone levels. People with different taste sensitivity may respond differently to the nutrient stimulation. Further work investigating the link between taste perception and peripheral metabolic control could

  12. Older men with low serum IGF-1 have an increased risk of incident fractures: the MrOS Sweden study.

    PubMed

    Ohlsson, Claes; Mellström, Dan; Carlzon, Daniel; Orwoll, Eric; Ljunggren, Osten; Karlsson, Magnus K; Vandenput, Liesbeth

    2011-04-01

    Osteoporosis-related fractures constitute a major health concern not only in women but also in men. Insulin-like growth factor 1 (IGF-1) is a key determinant of bone mass, but the association between serum IGF-1 and incident fractures in men remains unclear. To determine the predictive value of serum IGF-1 for fracture risk in men, older men (n = 2902, mean age of 75 years) participating in the prospective, population-based Osteoporotic Fractures in Men (MrOS) Sweden study were followed for a mean of 3.3 years. Serum IGF-1 was measured at baseline by radioimmunoassay. Fractures occurring after the baseline visit were validated. In age-adjusted hazards regression analyses, serum IGF-1 associated inversely with risk of all fractures [hazard ratio (HR) per SD decrease = 1.23, 95% confidence interval (CI) 1.07-1.41], hip fractures (HR per SD decrease = 1.45, 95% CI 1.07-1.97), and clinical vertebral fractures (HR per SD decrease = 1.40, 95% CI 1.10-1-78). The predictive role of serum IGF-1 for fracture risk was unaffected by adjustment for height, weight, prevalent fractures, falls, and major prevalent diseases. Further adjustment for bone mineral density (BMD) resulted in an attenuated but still significant association between serum IGF-1 and fracture risk. Serum IGF-1 below but not above the median was inversely related to fracture incidence. The population-attributable risk proportion was 7.5% for all fractures and 22.9% for hip fractures. Taken together, older men with low serum IGF-1 have an increased fracture risk, especially for the two most important fracture types, hip and vertebral fractures. The association between serum IGF-1 and fracture risk is partly mediated via BMD.

  13. MiR-143 and MiR-145 Regulate IGF1R to Suppress Cell Proliferation in Colorectal Cancer

    PubMed Central

    Wang, Nan; Zhang, Suyang; Yan, Xin; Feng, Hui; Pang, Wenjing; Wang, Yanbo; Wang, Xueliang; Fu, Zhen; Liu, Yanqing; Zhao, Chihao; Zhang, Junfeng; Zhang, Chen-Yu; Zen, Ke; Chen, Xi; Wang, Yalei

    2014-01-01

    Insulin-like growth factor 1 receptor (IGF1R) is a transmembrane receptor that is activated by insulin-like growth factor 1 (IGF-1) and by a related hormone called IGF-2. It belongs to the large class of tyrosine kinase receptors and plays an important role in colorectal cancer etiology and progression. In this study, we used bioinformatic analyses to search for miRNAs that potentially target IGF1R. We identified specific target sites for miR-143 and miR-145 (miR-143/145) in the 3′-untranslated region (3′-UTR) of the IGF1R gene. These miRNAs are members of a cluster of miRNAs that have been reported to exhibit tumor suppressor activity. Consistent with the bioinformatic analyses, we identified an inverse correlation between miR-143/145 levels and IGF1R protein levels in colorectal cancer tissues. By overexpressing miR-143/145 in Caco2, HT29 and SW480 colorectal cancer cells, we experimentally validated that miR-143/145 directly recognizes the 3′-UTR of the IGF1R transcript and regulates IGF1R expression. Furthermore, the biological consequences of the targeting of IGF1R by miR-143/145 were examined by cell proliferation assays in vitro. We demonstrated that the repression of IGF1R by miR-143/145 suppressed the proliferation of Caco2 cells. Taken together, our findings provide evidence for a role of the miR-143/145 cluster as a tumor suppressor in colorectal cancer through the inhibition of IGF1R translation. PMID:25474488

  14. Dauer-independent insulin/IGF-1-signalling implicates collagen remodelling in longevity

    PubMed Central

    Ewald, Collin Y.; Landis, Jess N.; Abate, Jess Porter; Murphy, Coleen T.; Blackwell, T. Keith

    2014-01-01

    Summary Interventions that delay ageing mobilize mechanisms that protect and repair cellular components1–3, but it is unknown how these interventions might slow the functional decline of extracellular matrices4,5, which are also damaged during ageing6,7. Reduced Insulin/IGF-1 signalling (rIIS) extends lifespan across the evolutionary spectrum, and in juvenile C. elegans also allows the transcription factor DAF-16/FOXO to induce development into dauer, a diapause that withstands harsh conditions (Supplementary Discussion)1,2. It has been suggested that rIIS delays C. elegans ageing through activation of dauer-related processes during adulthood2,8,9, but some rIIS conditions confer robust lifespan extension unaccompanied by any dauer-like traits1,10,11. Here we show that rIIS can promote C. elegans longevity through an program that is genetically distinct from the dauer pathway, and requires the Nrf (NF-E2-related factor) ortholog SKN-1 acting in parallel to DAF-16. SKN-1 is inhibited by IIS and has been broadly implicated in longevity12–14, but is rendered dispensable for rIIS lifespan extension by even mild activity of dauer-related processes. When IIS is decreased under conditions that do not induce dauer traits, SKN-1 most prominently increases expression of collagens and other extracellular matrix (ECM) genes. Diverse genetic, nutritional, and pharmacological pro-longevity interventions delay an age-related decline in collagen expression. These collagens mediate adulthood ECM remodelling, and are needed for ageing to be delayed by interventions that do not involve dauer traits. By genetically delineating a dauer-independent rIIS ageing pathway, our results show that IIS controls a broad set of protective mechanisms during C. elegans adulthood, and may facilitate elucidation of processes of general importance for longevity. The importance of collagen production in diverse anti-ageing interventions implies that ECM remodelling is a generally essential

  15. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    SciTech Connect

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  16. The key role of growth hormone — insulin — IGF-1 signaling in aging and cancer

    PubMed Central

    Anisimov, Vladimir N.; Bartke, Andrzej

    2014-01-01

    Studies in mammals have led to the suggestion that hyperglycemia and hyperinsulinemia are important factors in aging. GH/Insulin/insulin-like growth factor 1 (IGF-1) signaling molecules that have been linked to longevity include daf-2 and InR and their homologues in mammals, and inactivation of the corresponding genes increases lifespan in nematodes, fruit flies and mice. The life-prolonging effects of caloric restriction are likely related to decreasing IGF-1 levels. Evidence has emerged that antidiabetic drugs are promising candidates for both lifespan extension and prevention of cancer. Thus, antidiabetic drugs postpone spontaneous carcinogenesis in mice and rats, as well as chemical and radiation carcinogenesis in mice, rats and hamsters. Furthermore, metformin seems to decrease the risk for cancer in diabetic patients. PMID:23434537

  17. The insulin and IGF1 receptor kinase domains are functional dimers in the activated state

    NASA Astrophysics Data System (ADS)

    Cabail, M. Zulema; Li, Shiqing; Lemmon, Eric; Bowen, Mark E.; Hubbard, Stevan R.; Miller, W. Todd

    2015-03-01

    The insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R) are highly related receptor tyrosine kinases with a disulfide-linked homodimeric architecture. Ligand binding to the receptor ectodomain triggers tyrosine autophosphorylation of the cytoplasmic domains, which stimulates catalytic activity and creates recruitment sites for downstream signalling proteins. Whether the two phosphorylated tyrosine kinase domains within the receptor dimer function independently or cooperatively to phosphorylate protein substrates is not known. Here we provide crystallographic, biophysical and biochemical evidence demonstrating that the phosphorylated kinase domains of IR and IGF1R form a specific dimeric arrangement involving an exchange of the juxtamembrane region proximal to the kinase domain. In this dimer, the active position of α-helix C in the kinase N lobe is stabilized, which promotes downstream substrate phosphorylation. These studies afford a novel strategy for the design of small-molecule IR agonists as potential therapeutic agents for type 2 diabetes.

  18. Disparate Igf1 expression and growth in the fore- and hind limbs of a marsupial mammal (Monodelphis domestica).

    PubMed

    Sears, Karen E; Patel, Ankit; Hübler, Merla; Cao, Xiaoyi; Vandeberg, John L; Zhong, Sheng

    2012-06-01

    Proper regulation of growth is essential to all stages of life, from development of the egg into an embryo to the maintenance of normal cell cycle progression in adults. However, despite growth's importance to basic biology and health, little is known about how mammalian growth is regulated. In this study, we investigated the molecular basis of the highly disparate growth of opossum fore- and hind limbs in utero. We first used a novel, opossum-specific microarray to identify several growth-related genes that are differentially expressed in opossum fore- and hind limbs of comparable developmental stages. These genes included Igf1. Given Igf1's role in the growth of other systems, we further investigated the role of Igf1 in opossum limb growth. Supporting the microarray results, RT-PCR indicated that Igf1 levels are approximately two times higher in opossum fore- than hind limbs. Consistent with this, while Igf1 transcripts were readily detectable in opossum forelimbs using whole-mount in situ hybridization, they were not detectable in opossum hind limbs. Furthermore, opossum limbs treated with exogenous Igf1 protein experienced significantly greater cellular proliferation and growth than control limbs in vitro. Taken together, results suggest that the differential expression of Igf1 in developing opossum limbs contributes to their divergent rate of growth, and the unique limb phenotype of opossum newborns. This study establishes the opossum limb as a new mammalian model system for study of organ growth.

  19. Carotid Intima Media Thickness Is Independently Associated with Male Gender, Middle Age, and IGF-1 in Metabolically Healthy Obese Individuals.

    PubMed

    Abd El-Hafez, Hala; Elrakhawy, Mohamed M; El-Baiomy, Azza A; El-Eshmawy, Mervat M

    2014-01-01

    Background/Aims. The effect of benign obesity on subclinical cardiovascular disease is still questionable. The purpose of this study was to assess carotid intima media thickness (CIMT), as a marker of subclinical atherosclerosis, and to evaluate its relation to age, sex, and IGF-1 in metabolically healthy obese (MHO) subjects. Methods. A total of 75 MHO subjects and 80 age, and sex matched healthy nonobese control subjects were included in the study. Body mass index (BMI), waist circumference (WC), blood pressure, fasting plasma glucose, fasting insulin, HOMA-IR, lipid profile, insulin like growth factor-1 (IGF-1), and CIMT were assessed in all subjects. Results. MHO subjects had significantly higher CIMT and lower IGF-1 than healthy nonobese controls. Mean CIMT was significantly higher in MHO men age subgroup range from 30 to 50 years than in their age range matched (premenopausal) MHO women subgroup. In MHO subjects, CIMT was positively correlated with age, BMI, WC, SBP, HOMA-IR, TG, and LDL-C, and negatively correlated with IGF-1. Regression analysis revealed that middle age, male sex and IGF-1 remained independently associated with CIMT in MHO subjects. Conclusion. CIMT is elevated and IGF-1 is reduced in MHO subjects, and CIMT is independently associated with male gender, middle age, and IGF-1. Definition of healthy obesity may be broadened to include IMT measurement.

  20. Effects of calorie restriction and IGF-1 receptor blockade on the progression of 22Rv1 prostate cancer xenografts.

    PubMed

    Galet, Colette; Gray, Ashley; Said, Jonathan W; Castor, Brandon; Wan, Junxiang; Beltran, Pedro J; Calzone, Franck J; Elashoff, David; Cohen, Pinchas; Aronson, William J

    2013-07-03

    Calorie restriction (CR) inhibits prostate cancer progression, partially through modulation of the IGF axis. IGF-1 receptor (IGF-1R) blockade reduces prostate cancer xenograft growth. We hypothesized that combining calorie restriction with IGF-1R blockade would have an additive effect on prostate cancer growth. Severe combined immunodeficient mice were subcutaneously injected with 22Rv1 cells and randomized to: (1) Ad libitum feeding/intraperitoneal saline (Ad-lib); (2) Ad-lib/20 mg/kg twice weekly, intraperitoneal ganitumab [anti-IGF-1R antibody (Ad-lib/Ab)]; (3) 40% calorie restriction/intraperitoneal saline (CR); (4) CR/ intraperitoneal ganitumab, (CR/Ab). CR and ganitumab treatment were initiated one week after tumor injection. Euthanasia occurred 19 days post treatment. Results showed that CR alone decreased final tumor weight, plasma insulin and IGF-1 levels, and increased apoptosis. Ganitumab therapy alone reduced tumor growth but had no effect on final tumor weight. The combination therapy (CR/Ab) further decreased final tumor weight and proliferation, increased apoptosis in comparison to the Ad-lib group, and lowered plasma insulin levels relative to the Ad-lib and Ad-lib/Ab groups. Tumor AKT activation directly correlated with plasma IGF-1 levels. In conclusion, whereas ganitumab therapy modestly affected 22Rv1 tumor growth, combining IGF-1R blockade with calorie restriction resulted in a significant decrease in final tumor weight and improved metabolic profile.

  1. Carotid Intima Media Thickness Is Independently Associated with Male Gender, Middle Age, and IGF-1 in Metabolically Healthy Obese Individuals

    PubMed Central

    Abd El-Hafez, Hala; Elrakhawy, Mohamed M.; El-Baiomy, Azza A.; El-Eshmawy, Mervat M.

    2014-01-01

    Background/Aims. The effect of benign obesity on subclinical cardiovascular disease is still questionable. The purpose of this study was to assess carotid intima media thickness (CIMT), as a marker of subclinical atherosclerosis, and to evaluate its relation to age, sex, and IGF-1 in metabolically healthy obese (MHO) subjects. Methods. A total of 75 MHO subjects and 80 age, and sex matched healthy nonobese control subjects were included in the study. Body mass index (BMI), waist circumference (WC), blood pressure, fasting plasma glucose, fasting insulin, HOMA-IR, lipid profile, insulin like growth factor-1 (IGF-1), and CIMT were assessed in all subjects. Results. MHO subjects had significantly higher CIMT and lower IGF-1 than healthy nonobese controls. Mean CIMT was significantly higher in MHO men age subgroup range from 30 to 50 years than in their age range matched (premenopausal) MHO women subgroup. In MHO subjects, CIMT was positively correlated with age, BMI, WC, SBP, HOMA-IR, TG, and LDL-C, and negatively correlated with IGF-1. Regression analysis revealed that middle age, male sex and IGF-1 remained independently associated with CIMT in MHO subjects. Conclusion. CIMT is elevated and IGF-1 is reduced in MHO subjects, and CIMT is independently associated with male gender, middle age, and IGF-1. Definition of healthy obesity may be broadened to include IMT measurement. PMID:24616825

  2. Association between GNRHR, LHR and IGF1 polymorphisms and timing of puberty in male Angus cattle

    PubMed Central

    2012-01-01

    Background In bovines, there are significant differences within and among beef breeds in the time when bulls reach puberty. Although the timing of puberty is likely to be a multigenic trait, previous studies indicate that there may also be single genes that exert major effects on the timing of puberty within the general population. Despite its economic importance, there are not many SNPs or genetic markers associated with the age of puberty in male cattle. In the present work, we selected three candidate genes, GNRHR, LHR and IGF1, and associated their polymorphisms with the age of puberty in Angus male cattle. Results After weaning, 276 Angus males were measured every month for weight (W), scrotal circumference (SC), sperm concentration (C) and percentage of motility (M). A total of 4 SNPs, two within GNRHR, one in LHR and one in IGF1 were genotyped using the pyrosequencing technique. IGF1-SnaBI SNP was significant associated (P < 0.01) with age at SC 28 cm, but it were not associated with age at M 10% and C 50 million. Genotype CC exhibited an average age at SC 28 cm of 7 and 11 days higher than CT (p = 0.037) and TT (p = 0.012), respectively. This SNP explained 1.5% of the genetic variance of age of puberty at SC28. LHR-I499L, GNRHR-SNP5 and GNRHR-SNP6 were not associated with any of the measurements. However, GNRHR haplotypes showed a suggestive association with age at SC 28 cm. Conclusions The findings presented here could support the hypothesis that IGF1 is a regulator of the arrival to puberty in male calves and is involved in the events that precede and initiate puberty in bull calves. Given that most studies in cattle, as well as in other mammals, were done in female, the present results are the first evidence of markers associated with age at puberty in male cattle. PMID:22480211

  3. Localized SCF and IGF-1 secretion enhances erythropoiesis in the spleen of murine embryos

    PubMed Central

    Tan, Keai Sinn; Inoue, Tomoko; Kulkeaw, Kasem; Tanaka, Yuka; Lai, Mei I; Sugiyama, Daisuke

    2015-01-01

    Fetal spleen is a major hematopoietic site prior to initiation of bone marrow hematopoiesis. Morphologic analysis suggested erythropoietic activity in fetal spleen, but it remained unclear how erythropoiesis was regulated. To address this question, we performed flow cytometric analysis and observed that the number of spleen erythroid cells increased 18.6-fold from 16.5 to 19.5 days post-coitum (dpc). Among erythropoietic cytokines, SCF and IGF-1 were primarily expressed in hematopoietic, endothelial and mesenchymal-like fetal spleen cells. Cultures treated with SCF and/or IGF-1R inhibitors showed significantly decreased CD45−c-Kit−CD71+/−Ter119+ erythroid cells and downregulated Gata1, Klf1 and β-major globin expression. Administration of these inhibitors to pregnant mice significantly decreased the number of CD45−c-Kit−CD71+/−Ter119+ cells and downregulated β-major globin gene expression in embryos derived from these mice. We conclude that fetal spleen is a major erythropoietic site where endothelial and mesenchymal-like cells primarily accelerate erythropoietic activity through SCF and IGF-1 secretion. PMID:25887124

  4. Role of CRP, TNF-a, and IGF-1 in Delirium Pathophysiology

    PubMed Central

    ÇINAR, Mehmet Alper; BALIKÇI, Adem; SERTOĞLU, Erdim; Mehmet, AK; SERDAR, Muhittin A.; ÖZMENLER, Kamil Nahit

    2014-01-01

    Introduction Delirium is a common and life-threatening neuropsychiatric syndrome. Diagnosing delirium can be challenging, which increases mortality and mortality rates and health care costs. The biologic model of delirium is not definite yet, but evidence supports a cholinergic deficiency model. Delirium may be the result of processes and drugs that trespass a compromised blood-brain barrier. We aimed to evaluate the possible diagnostic utilization and the role of certain biomarkers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and insulin like growth factor-1 (IGF-1), in delirium etiology. Methods A total of 93 inpatients that planned to undergo cardiovascular surgery were informed; 35 of them completed the study. Medical history and current cognitive status were evaluated pre-operatively. Participants were followed using Delirium Rating Scale-Revised-98 Turkish (DRS-R98-T) for delirium symptoms, and blood samples were collected post-operatively. Results Delirium was developed more in participants who had worse pre-operative cognitive status. Also, low pre-operative IGF-1 levels were detected in the delirium group. Pre-operative CRP and TNF-α levels were not different between groups. Conclusion Low IGF-1 levels can be used to predict delirium after surgery. However, the complex nature of cytokines and delirium itself make it difficult to utilize cytokines to predict delirium instead of psychometric tools.

  5. Mechanism of activation of protein kinase B by insulin and IGF-1.

    PubMed Central

    Alessi, D R; Andjelkovic, M; Caudwell, B; Cron, P; Morrice, N; Cohen, P; Hemmings, B A

    1996-01-01

    Insulin activated endogenous protein kinase B alpha (also known as RAC/Akt kinase) activity 12-fold in L6 myotubes, while after transfection into 293 cells PKBalpha was activated 20- and 50-fold in response to insulin and IGF-1 respectively. In both cells, the activation of PKBalpha was accompanied by its phosphorylation at Thr308 and Ser473 and, like activation, phosphorylation of both of these residues was prevented by the phosphatidylinositol 3-kinase inhibitor wortmannin. Thr308 and/or Ser473 were mutated to Ala or Asp and activities of mutant PKBalpha molecules were analysed after transfection into 293 cells. The activity of wild-type and mutant PKBalpha was also measured in vitro after stoichiometric phosphorylation of Ser473 by MAPKAP kinase-2. These experiments demonstrated that activation of PKBalpha by insulin or insulin-like growth factor-1 (IGF-1) results from phosphorylation of both Thr308 and Ser473, that phosphorylation of both residues is critical to generate a high level of PKBalpha activity and that the phosphorylation of Thr308 in vivo is not dependent on phosphorylation of Ser473 or vice versa. We propose a model whereby PKBalpha becomes phosphorylated and activated in insulin/IGF-1-stimulated cells by an upstream kinase(s). Images PMID:8978681

  6. Virtual Screening of Specific Insulin-Like Growth Factor 1 Receptor (IGF1R) Inhibitors from the National Cancer Institute (NCI) Molecular Database

    PubMed Central

    Fan, Cong; Huang, Yan-Xin; Bao, Yong-Li; Sun, Lu-Guo; Wu, Yin; Yu, Chun-Lei; Zhang, Yu; Song, Zhen-Bo; Zheng, Li-Hua; Sun, Ying; Wang, Guan-Nan; Li, Yu-Xin

    2012-01-01

    Insulin-like growth factor 1 receptor (IGF1R) is an attractive drug target for cancer therapy and research on IGF1R inhibitors has had success in clinical trials. A particular challenge in the development of specific IGF1R inhibitors is interference from insulin receptor (IR), which has a nearly identical sequence. A few potent inhibitors that are selective for IGF1R have been discovered experimentally with the aid of computational methods. However, studies on the rapid identification of IGF1R-selective inhibitors using virtual screening and confidence-level inspections of ligands that show different interactions with IGF1R and IR in docking analysis are rare. In this study, we established virtual screening and binding-mode prediction workflows based on benchmark results of IGF1R and several kinase receptors with IGF1R-like structures. We used comprehensive analysis of the known complexes of IGF1R and IR with their binding ligands to screen specific IGF1R inhibitors. Using these workflows, 17 of 139,735 compounds in the NCI (National Cancer Institute) database were identified as potential specific inhibitors of IGF1R. Calculations of the potential of mean force (PMF) with GROMACS were further conducted for three of the identified compounds to assess their binding affinity differences towards IGF1R and IR. PMID:23242155

  7. Tracking Spinal Cord Injury: Differences in Cytokine Expression of IGF-1, TGF- B1, and sCD95l Can Be Measured in Blood Samples and Correspond to Neurological Remission in a 12-Week Follow-Up.

    PubMed

    Ferbert, Thomas; Child, Christopher; Graeser, Viola; Swing, Tyler; Akbar, Michael; Heller, Raban; Biglari, Bahram; Moghaddam, Arash

    2017-02-01

    Neuroinflammation presumably has an important impact on the secondary phase of spinal cord injury and is regulated by pro- and anti-inflammatory cytokines. We analyzed serum levels of three different cytokines (insulin-like-growth-factor [IGF]-1, tumor growth factor [TGF]-β1, and soluble CD 95 ligand [sCD95L]), in blood samples of 23 patients admitted with acute traumatic spinal cord injury between November 2010 and July 2013 with a follow-up period of 12 weeks. Quantification was performed using Human Quantikine Immunoassays, classification of neurological impairment was performed using the American Spinal Cord Injury Impairment Scale at time of admission and after 12 weeks. After an initial drop of all three cytokine serum levels, IGF-1, TGF-β1, and sCD95L showed significantly increased serum levels during the acute and sub-acute phases. For IGF-1 and sCD95L, we could also observe significantly higher serum levels in patients without neurological improvement compared with patients who had improvement after 12 weeks. In this study, we were able to show differences in cytokine serum levels in patients with different neurological outcome. Measuring the serum level patterns of IGF-1, TGF-β1, and sCD95L might be a useful tool for prognosis in patients with neurological improvement and tracking the pathophysiology in further studies. Further, our observations might link promising therapeutic efforts in numerous animal studies and future studies in human patients.

  8. Serum IGF-1 and IGFBP-3 Levels in Healthy Children Between 0 and 6 Years of Age

    PubMed Central

    Yüksel, Bilgin; Özbek, M. Nuri; Mungan, Neslihan Önenli; Darendeliler, Feyza; Budan, Bahar; Bideci, Aysun; Çetinkaya, Ergün; Berberoğlu, Merih; Evliyaoğlu, Olcay; Yeşilkaya, Ediz; Arslanoğlu, İlknur; Darcan, Şükran; Bundak, Ruveyda; Ercan, Olcay

    2011-01-01

    Objective: Along with growth hormone (GH) levels, measurements of serum insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) are used in the diagnosis of GH deficiency and in monitoring the efficacy and safety of long-term GH treatment. The purpose of the present study was to establish reference values for serum IGF-1 and IGFBP-3 in healthy Turkish children less than 6 years of age. Methods: This study was designed as a multicenter project. Five hundred sixty-seven healthy children younger than 6 years of age from different geographical regions of Turkey, with weight and height values between the 10th and 90th percentiles according to the national standards were included in the study. In addition to anthropometric parameters, serum IGF-1 and IGFBP-3 levels were measured in all subjects. Results: Although not statistically significant, the serum IGF-1 levels in infants at age 6 months were lower than those in infants at age 3 months. The IGF-1 levels showed a slow increase with age. Serum IGF-1 levels were lower in girls as compared to boys only at age 6 months. No correlation was found between either serum IGFBP-3 levels and body mass index (BMI) or serum IGFBP-3 and weight and height standard deviation scores (SDS). A weak correlation was observed between serum IGF-1 and IGFBP-3 concentrations. Conclusions: The age- and gender-specific reference values for serum IGF-1 and IGFBP-3 reported in this study will aid in the diagnosis of GH deficiency and in the monitoring of children receiving GH treatment. Conflict of interest:None declared. PMID:21750637

  9. Association between dynamic exercise therapy and IGF-1 and IGFBP-3 concentrations in the patients with rheumatoid arthritis.

    PubMed

    Melikoglu, Meltem Alkan; Karatay, Saliha; Senel, Kazim; Akcay, Fatih

    2006-02-01

    We aimed to evaluate the relationship between short-term dynamic exercise therapy and insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) levels in rheumatoid arthritis (RA) patients. Forty RA patients were assigned into dynamic or range of motion (ROM) exercise groups. Also control group carried out the same dynamic exercise protocol. Morning stiffness, pain (VAS), Health assessment questionnaire (HAQ) and Ritchie articular index (RAI) were evaluated and erythrocyte sedimentation rate, serum C-reactive protein, IGF-1 and IGFBP-3 levels of the participants were recorded. The assessments were determined before, at the 7th and 15th days of treatment. VAS and RAI scores were significantly improved by the dynamic exercises in RA patients. There were increases on IGF-1 in dynamic exercise group, although IGF-1 levels showed a decrease in ROM exercise and control groups. Also no significant changes were observed on IGFBP-3 in three groups. Our results suggest that short-term dynamic exercise therapy increases serum IGF-1 in RA patients. The manipulation of serum IGF-1 levels by dynamic exercise therapy may indicate the beneficial effects of dynamic exercise in RA patients.

  10. Regulation of skeletal growth and mineral acquisition by the GH/IGF-1 axis: Lessons from mouse models.

    PubMed

    Yakar, Shoshana; Isaksson, Olle

    2016-06-01

    The growth hormone (GH) and its downstream mediator, the insulin-like growth factor-1 (IGF-1), construct a pleotropic axis affecting growth, metabolism, and organ function. Serum levels of GH/IGF-1 rise during pubertal growth and associate with peak bone acquisition, while during aging their levels decline and associate with bone loss. The GH/IGF-1 axis was extensively studied in numerous biological systems including rodent models and cell cultures. Both hormones act in an endocrine and autocrine/paracrine fashion and understanding their distinct and overlapping contributions to skeletal acquisition is still a matter of debate. GH and IGF-1 exert their effects on osteogenic cells via binding to their cognate receptor, leading to activation of an array of genes that mediate cellular differentiation and function. Both hormones interact with other skeletal regulators, such as sex-steroids, thyroid hormone, and parathyroid hormone, to facilitate skeletal growth and metabolism. In this review we summarized several rodent models of the GH/IGF-1 axis and described key experiments that shed new light on the regulation of skeletal growth by the GH/IGF-1 axis.

  11. Compounds from the marine sponge Cribrochalina vasculum offer a way to target IGF-1R mediated signaling in tumor cells

    PubMed Central

    Zovko, Ana; Novak, Metka; Hååg, Petra; Kovalerchick, Dimitry; Holmlund, Teresa; Färnegårdh, Katarina; Ilan, Micha; Carmeli, Shmuel; Lewensohn, Rolf; Viktorsson, Kristina

    2016-01-01

    In this work two acetylene alcohols, compound 1 and compound 2, which were isolated and identified from the sponge Cribrochalina vasculum, and which showed anti-tumor effects were further studied with respect to targets and action mechanisms. Gene expression analyses suggested insulin like growth factor receptor (IGF-1R) signaling to be instrumental in controlling anti-tumor efficacy of these compounds in non-small cell lung cancer (NSCLC). Indeed compounds 1 and 2 inhibited phosphorylation of IGF-1Rβ as well as reduced its target signaling molecules IRS-1 and PDK1 allowing inhibition of pro-survival signaling. In silico docking indicated that compound 1 binds to the kinase domain of IGF-1R at the same binding site as the well known tyrosine kinase inhibitor AG1024. Indeed, cellular thermal shift assay (CETSA) confirmed that C. vasculum compound 1 binds to IGF-1R but not to the membrane localized tyrosine kinase receptor EGFR. Importantly, we demonstrate that compound 1 causes IGF-1Rβ but not Insulin Receptor degradation specifically in tumor cells with no effects seen in normal diploid fibroblasts. Thus, these compounds hold potential as novel therapeutic agents targeting IGF-1R signaling for anti-tumor treatment. PMID:27384680

  12. Inhibitors of STAT3, β-catenin, and IGF-1R sensitize mouse PIK3CA-mutant breast cancer to PI3K inhibitors.

    PubMed

    Merino, Vanessa F; Cho, Soonweng; Liang, Xiaohui; Park, Sunju; Jin, Kideok; Chen, Qian; Pan, Duojia; Zahnow, Cynthia A; Rein, Alan R; Sukumar, Saraswati

    2017-03-15

    Although mutations in the phosphoinositide 3-kinase catalytic subunit (PIK3CA) are common in breast cancer, PI3K inhibitors alone have shown modest efficacy. We sought to identify additional pathways altered in PIK3CA-mutant tumors that might be targeted in combination with PI3K inhibitors. We generated two transgenic mouse models expressing the human PIK3CA-H1047R- and the -E545K hotspot-mutant genes in the mammary gland and evaluated their effects on development and tumor formation. Molecular analysis identified pathways altered in these mutant tumors, which were also targeted in multiple cell lines derived from the PIK3CA tumors. Finally, public databases were analyzed to determine whether novel pathways identified in the mouse tumors were altered in human tumors harboring mutant PIK3CA. Mutant mice showed increased branching and delayed involution of the mammary gland compared to parental FVB/N mice. Mammary tumors arose in 30% of the MMTV-PIK3CA-H1047R and in 13% of -E545K mice. Compared to MMTV-Her-2 transgenic mouse mammary tumors, H1047R tumors showed increased upregulation of Wnt/β-catenin/Axin2, hepatocyte growth factor (Hgf)/Stat3, insulin-like growth factor 2 (Igf-2), and Igf-1R pathways. Inhibitors of STAT3, β-catenin, and IGF-1R sensitized H1047R-derived mouse tumor cells and PIK3CA-H1047R overexpressing human HS578T breast cancer cells to the cytotoxic effects of PI3K inhibitors. Analysis of The Cancer Genome Atlas database showed that, unlike primary PIK3CA-wild-type and HER-2(+) breast carcinomas, PIK3CA-mutant tumors display increased expression of AXIN2, HGF, STAT3, IGF-1, and IGF-2 mRNA and activation of AKT, IGF1-MTOR, and WNT canonical signaling pathways. Drugs targeting additional pathways that are altered in PIK3CA-mutant tumors may improve treatment regimens using PI3K inhibitors alone.

  13. Identification of a gonad-expression differential gene insulin-like growth factor-1 receptor (Igf1r) in the swamp eel (Monopterus albus).

    PubMed

    Mei, Jie; Yan, Wei; Fang, Jie; Yuan, Gailing; Chen, Nan; He, Yan

    2014-08-01

    In vertebrate species, the biopotential embryonic gonad differentiation is affected by many key genes and key steroidogenic enzymes. Insulin-like growth factor-1 receptor (Igf1r) has been considered as an important sex-differentiation gene in mammals and could mediate the biological action of Igf1, an important regulator of key steroidogenic enzymes. However, Igf1r gene is still unknown in the swamp eel, an economically important fish. In our study, we identified Igf1r gene in the swamp eel, which was a 2,148-bp open-reading frame encoding a protein of 716 amino acids. The alignment and the phylogenetic tree showed that Igf1r of the swamp eel had a conservative sequence with other vertebrates, especial fishes. Western blotting of Igf1r showed that Igf1r expressed much more in ovotestis and testis than in ovary, indicating an important role of Igf1r during gonad differentiation. We analyzed ubiquitination of Igf1r by co-immunoprecipitation and found the amount of ubiquitinated Igf1r was increased from ovary, ovotestis to testis, which was reversely to the trend of Hsp10 expression during gonadal transformation. It was possible that Hsp10 could suppress Igf1r ubiquitination during gonadal development of the swamp eel.

  14. Picropodophyllin inhibits tumor growth of human nasopharyngeal carcinoma in a mouse model

    SciTech Connect

    Yin, Shu-Cheng; Guo, Wei; Tao, Ze-Zhang

    2013-09-13

    Highlights: •We identified that PPP inhibits IGF-1R/Akt pathway in NPC cells. •PPP dose-dependently inhibits NPC cell proliferation in vitro. •PPP suppresses tumor growth of NPC in nude mice. •PPP have little effect on microtubule assembly. -- Abstract: Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor with tyrosine kinase activity and plays important roles in cell transformation, tumor growth, tumor invasion, and metastasis. Picropodophyllin (PPP) is a selective IGF-1R inhibitor and shows promising antitumor effects for several human cancers. However, its antitumor effects in nasopharyngeal carcinoma (NPC) remain unclear. The purpose of this study is to investigate the antitumor activity of PPP in NPC using in vitro cell culture and in vivo animal model. We found that PPP dose-dependently decreased the IGF-induced phosphorylation and activity of IGF-1R and consequently reduced the phosphorylation of Akt, one downstream target of IGF-1R. In addition, PPP inhibited NPC cell proliferation in vitro. The half maximal inhibitory concentration (IC50) of PPP for NPC cell line CNE-2 was ⩽1 μM at 24 h after treatment and ⩽0.5 μM at 48 h after treatment, respectively. Moreover, administration of PPP by intraperitoneal injection significantly suppressed the tumor growth of xenografted NPC in nude mice. Taken together, these results suggest targeting IGF-1R by PPP may represent a new strategy for treatment of NPCs with positive IGF-1R expression.

  15. IGF1R- and ROR1-Specific CAR T Cells as a Potential Therapy for High Risk Sarcomas.

    PubMed

    Huang, Xin; Park, Haein; Greene, Joseph; Pao, James; Mulvey, Erin; Zhou, Sophia X; Albert, Catherine M; Moy, Fred; Sachdev, Deepali; Yee, Douglas; Rader, Christoph; Hamby, Carl V; Loeb, David M; Cairo, Mitchell S; Zhou, Xianzheng

    2015-01-01

    Patients with metastatic or recurrent and refractory sarcomas have a dismal prognosis. Therefore, new targeted therapies are urgently needed. This study was designed to evaluate chimeric antigen receptor (CAR) T cells targeting the type I insulin-like growth factor receptor (IGF1R) or tyrosine kinase-like orphan receptor 1 (ROR1) molecules for their therapeutic potential against sarcomas. Here, we report that IGF1R (15/15) and ROR1 (11/15) were highly expressed in sarcoma cell lines including Ewing sarcoma, osteosarcoma, alveolar or embryonal rhabdomyosarcoma, and fibrosarcoma. IGF1R and ROR1 CAR T cells derived from eight healthy donors using the Sleeping Beauty (SB) transposon system were cytotoxic against sarcoma cells and produced high levels of IFN-γ, TNF-α and IL-13 in an antigen-specific manner. IGF1R and ROR1 CAR T cells generated from three sarcoma patients released significant amounts of IFN-γ in response to sarcoma stimulation. The adoptive transfer of IGF1R and ROR1 CAR T cells derived from a sarcoma patient significantly reduced tumor growth in pre-established, systemically disseminated and localized osteosarcoma xenograft models in NSG mice. Infusion of IGF1R and ROR1 CAR T cells also prolonged animal survival in a localized sarcoma model using NOD/scid mice. Our data indicate that both IGF1R and ROR1 can be effectively targeted by SB modified CAR T cells and that such CAR T cells may be useful in the treatment of high risk sarcoma patients.

  16. IGF1R- and ROR1-Specific CAR T Cells as a Potential Therapy for High Risk Sarcomas

    PubMed Central

    Huang, Xin; Park, Haein; Greene, Joseph; Zhou, Sophia X.; Albert, Catherine M.; Moy, Fred; Sachdev, Deepali; Yee, Douglas; Rader, Christoph; Hamby, Carl V.; Loeb, David M.; Cairo, Mitchell S.; Zhou, Xianzheng

    2015-01-01

    Patients with metastatic or recurrent and refractory sarcomas have a dismal prognosis. Therefore, new targeted therapies are urgently needed. This study was designed to evaluate chimeric antigen receptor (CAR) T cells targeting the type I insulin-like growth factor receptor (IGF1R) or tyrosine kinase-like orphan receptor 1 (ROR1) molecules for their therapeutic potential against sarcomas. Here, we report that IGF1R (15/15) and ROR1 (11/15) were highly expressed in sarcoma cell lines including Ewing sarcoma, osteosarcoma, alveolar or embryonal rhabdomyosarcoma, and fibrosarcoma. IGF1R and ROR1 CAR T cells derived from eight healthy donors using the Sleeping Beauty (SB) transposon system were cytotoxic against sarcoma cells and produced high levels of IFN-γ, TNF-α and IL-13 in an antigen-specific manner. IGF1R and ROR1 CAR T cells generated from three sarcoma patients released significant amounts of IFN-γ in response to sarcoma stimulation. The adoptive transfer of IGF1R and ROR1 CAR T cells derived from a sarcoma patient significantly reduced tumor growth in pre-established, systemically disseminated and localized osteosarcoma xenograft models in NSG mice. Infusion of IGF1R and ROR1 CAR T cells also prolonged animal survival in a localized sarcoma model using NOD/scid mice. Our data indicate that both IGF1R and ROR1 can be effectively targeted by SB modified CAR T cells and that such CAR T cells may be useful in the treatment of high risk sarcoma patients. PMID:26173023

  17. miR-1827 inhibits osteogenic differentiation by targeting IGF1 in MSMSCs

    PubMed Central

    Zhu, ShuangXi; Peng, Wei; Li, Xiang; Weng, JunQuan; Zhang, Xing; Guo, JunBing; Huang, DaiYing; Rong, Qiong; Chen, SongLing

    2017-01-01

    We recently reported that maxillary sinus membrane stem cells (MSMSCs) have osteogenic potential. However, the biological mechanisms of bone formation remain unclear. In this study, we investigated the role and mechanisms of microRNAs (miRNAs) in the osteogenic differentiation of MSMSCs. The expression of miRNAs was determined in differentiated MSMSCs by comprehensive miRNA microarray analysis and quantitative RT-PCR (qRT-PCR). We selected miR-1827 for functional follow-up studies to explore its significance in MSMSCs. Here, miR-1827 was found to be up-regulated during osteogenic differentiation of MSMSCs. Over expression of miR-1827 inhibited osteogenic differentiation of MSMSCs in vitro, whereas the repression of miR-1827 greatly promoted cell differentiation. Further experiments confirmed that insulin-like growth factor 1 (IGF1) is a direct target of miR-1827. miR-1827 inhibited osteogenic differentiation partially via IGF1, which in turn is a positive regulator of osteogenic differentiation. Moreover, miR-1827 suppressed ectopic bone formation and silencing of miR-1827 led to increased bone formation in vivo. In summary, this study is the first to demonstrate that miR-1827 can regulate osteogenic differentiation. The increase in miR-1827 expression observed during osteogenesis is likely a negative feedback mechanism, thus offering a potential therapeutic target to address inadequate bone volume for dental implantation through inhibiting miR-1827. PMID:28387248

  18. Mutation R273H confers p53 a stimulating effect on the IGF-1R-AKT pathway via miR-30a suppression in breast cancer.

    PubMed

    Guo, Fangdong; Chen, Hongshen; Chang, Jian; Zhang, Lin

    2016-03-01

    p53 is the most highly mutated tumor suppressor in human malignancies. A wide array of p53 mutations has been revealed to play pivotal roles during cancer progression, which abolish anti-tumor functions of wild type p53 but also elicit tumorigenic effects by activating a diverse subset of downstream molecules. R273H mutation of p53 has been closely implicated in human cancer. Here we report miR-30a as a novel downstream target of p53 R273H mutant, which binds to the promoter region to repress miR-30a expression. Consequently, p53 R273H mutant enhances the migratory capabilities of tumor cells that are compromised by exogenous miR-30a over-expression. Our further investigation indicates that p53 R273H mutation unleashes the inhibition effect of miR-30a on IGF-1R expression, thus leading to elevated activation of IGF-1R-AKT signaling cascade in tumor cells.

  19. Enhanced athletic performance on multisite AAV-IGF1 gene transfer coincides with massive modification of the muscle proteome.

    PubMed

    Macedo, Antero; Moriggi, Manuela; Vasso, Michele; De Palma, Sara; Sturnega, Mauro; Friso, Giorgio; Gelfi, Cecilia; Giacca, Mauro; Zacchigna, Serena

    2012-02-01

    Progress in gene therapy has hinted at the potential misuse of gene transfer in sports to achieve better athletic performance, while escaping from traditional doping detection methods. Suitable animal models are therefore required in order to better define the potential effects and risks of gene doping. Here we describe a mouse model of gene doping based on adeno-associated virus (AAV)-mediated delivery of the insulin-like growth factor-I (IGF-I) cDNA to multiple muscles. This treatment determined marked muscle hypertrophy, neovascularization, and fast-to-slow fiber type transition, similar to endurance exercise. In functional terms, treated mice showed impressive endurance gain, as determined by an exhaustive swimming test. The proteomic profile of the transduced muscles at 15 and 30 days after gene delivery revealed induction of key proteins controlling energy metabolism. At the earlier time point, enzymes controlling glycogen mobilization and anaerobic glycolysis were induced, whereas they were later replaced by proteins required for aerobic metabolism, including enzymes related to the Krebs cycle and oxidative phosphorylation. These modifications coincided with the induction of several structural and contractile proteins, in agreement with the observed histological and functional changes. Collectively, these results give important insights into the biological response of muscles to continuous IGF-I expression in vivo and warn against the potential misuse of AAV-IGF1 as a doping agent.

  20. Effect of recombinant human growth hormone on age-related hepatocyte changes in old male and female Wistar rats.

    PubMed

    Castillo, Carmen; Salazar, Veronica; Ariznavarreta, Carmen; Vara, Elena; Tresguerres, Jesus A F

    2004-10-01

    Aging induces changes in several organs, such as the liver, and this process might be due to damage caused by free radicals and inflammatory mediators. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis shows a reduction with age, and this fact could be associated with some age-related changes. The aim of this study was to investigate the effect of GH administration on age-induced alterations in hepatocytes. Two and twenty two month-old male and female Wistar rats were used. Old rats were treated with human recombinant GH for 10 wk. At the end of the treatment, hepatocytes were isolated from the liver and cultured, and different parameters were measured in cells and medium. Plasma IGF-1 was also measured. Aging significantly decreased plasma IGF-1 in males. In females, plasma IGF-1 was also reduced, but not significantly. GH treatment restored plasma IGF-1 levels to values similar to young males. Aging was associated with a significant increase in lipid peroxidation (LPO), nitric oxide (NO), carbon monoxide (CO) and cyclic guanosyl-monophosphate (cGMP), as well as a reduction in adenosyl triphosphate (ATP) and phosphatidylcholine (PC) synthesis. GH administration partially prevented all these changes in males. In females, some of the parameters were significantly improved by GH (ATP, CO, cGMP), while others showed a tendency to improvement, although differences did not reach significance. In conclusion, GH administration could exert beneficial effects against age-related changes in hepatocytes, mainly in males.

  1. Motor neuron targeting of IGF-1 attenuates age-related external Ca2+-dependent skeletal muscle contraction in senescent mice.

    PubMed

    Payne, Anthony M; Messi, María Laura; Zheng, Zhenlin; Delbono, Osvaldo

    2007-04-01

    A population of fast muscle fibers from aging mice is dependent on external Ca(2+) to maintain tetanic force during repeated contractions. We hypothesized that age-related denervation in muscle fibers plays a role in initiating this contractile deficit, and that prevention of denervation by IGF-1 overexpression would prevent external Ca(2+)-dependent contraction in aging mice. IGF-1 overexpression in skeletal muscle prevents age-related denervation, and prevented external Ca(2+)-dependent contraction in this work. To determine if the effects of IGF-1 overexpression are on muscle or nerve, aging mice were injected with a tetanus toxin fragment-C (TTC) fusion protein that targets IGF-1 to spinal cord motor neurons. This treatment prevented external Ca(2+)-dependent contraction. We also show evidence that injections of the IGF-1-TTC fusion protein prevent age-related alterations to the nerve terminals at the neuromuscular junctions. We conclude that the slow age-related denervation of fast muscle fibers underlies dependence on external Ca(2+) to maintain tetanic force in a population of muscle fibers from senescent mice.

  2. Expression of brain-derived neurotrophic factor, IGF-1 and cortisol elicited by regular aerobic exercise in adolescents

    PubMed Central

    Jeon, Yong Kyun; Ha, Chang Ho

    2015-01-01

    [Purpose] This study was conducted on adolescent subjects whose brains are still developing with the purpose of identifying the effect of 8 weeks duration of aerobic exercises on the expression of BDNF, IGF-1 and cortisol, to identify effect of aerobic exercise on the expression of cortisol, BDNF and IGF-1 related to nerve cell growth. [Subjects and Methods] The subjects were 20 junior-high school students with no history of physical illness. The students were divided into an exercise group and a control group. The exercise group performed 3 treadmill exercise times per week for 8 weeks. The exercise time for the consumption of 200 kcal was calculated and the exercises were performed by each individual for 8 weeks. [Results] The exercise group showed statistically significant in increases serum BDNF and IGF-1 after 8 weeks, but cortisol showed no significant change. There were statistically significant differences between the groups in serum BDNF and IGF-1 after 8 weeks, but the difference in cortisol levels was not significant. [Conclusion] We found that long-term regular aerobic exercises has a positive effect on the enhancement of serum BDNF levels at rest and IGF-1 of adolescents who are still undergoing through brain developments. PMID:25931720

  3. Expression of brain-derived neurotrophic factor, IGF-1 and cortisol elicited by regular aerobic exercise in adolescents.

    PubMed

    Jeon, Yong Kyun; Ha, Chang Ho

    2015-03-01

    [Purpose] This study was conducted on adolescent subjects whose brains are still developing with the purpose of identifying the effect of 8 weeks duration of aerobic exercises on the expression of BDNF, IGF-1 and cortisol, to identify effect of aerobic exercise on the expression of cortisol, BDNF and IGF-1 related to nerve cell growth. [Subjects and Methods] The subjects were 20 junior-high school students with no history of physical illness. The students were divided into an exercise group and a control group. The exercise group performed 3 treadmill exercise times per week for 8 weeks. The exercise time for the consumption of 200 kcal was calculated and the exercises were performed by each individual for 8 weeks. [Results] The exercise group showed statistically significant in increases serum BDNF and IGF-1 after 8 weeks, but cortisol showed no significant change. There were statistically significant differences between the groups in serum BDNF and IGF-1 after 8 weeks, but the difference in cortisol levels was not significant. [Conclusion] We found that long-term regular aerobic exercises has a positive effect on the enhancement of serum BDNF levels at rest and IGF-1 of adolescents who are still undergoing through brain developments.

  4. Positive effects of aerobic exercise on learning and memory functioning, which correlate with hippocampal IGF-1 increase in adolescent rats.

    PubMed

    Cetinkaya, Caner; Sisman, Ali Riza; Kiray, Muge; Camsari, Ulas Mehmet; Gencoglu, Celal; Baykara, Basak; Aksu, Ilkay; Uysal, Nazan

    2013-08-09

    It is already known that regular aerobic exercise during adolescent period improves learning and memory in rats. In this study, we investigated the effects of regular aerobic exercise on learning, memory functioning and IGF-1 levels. IGF-1 is known to have positive effects on cognitive functions in adolescent rats. Exercise group was separated into two different groups. First half was run on a treadmill for 30 min per session at a speed of 8m/min and 0° slope, five times a week for 6 weeks. The second half was given free access to a running wheel (diameter 11.5 cm) which was connected to a digital counter and run on a treadmill for 6 weeks. Learning and memory functioning were found to be positively correlated with the exercise activity. Findings suggest increased neuron density in CA1 hippocampal region and dentate gyrus. Increased IGF-1 level was detected in hippocampus and blood serum, while IGF-1 level in liver tissue did not change with exercise activity. In conclusion, our findings indicate that learning and memory functioning were positively affected by voluntary and involuntary physical exercise which correlated increased hippocampal activity and elevated IGF-1 levels in adolescent rats.

  5. Over-accumulation of nuclear IGF-1 receptor in tumor cells requires elevated expression of the receptor and the SUMO-conjugating enzyme Ubc9

    SciTech Connect

    Deng, Hua; Lin, Yingbo; Badin, Margherita; Vasilcanu, Daiana; Stroemberg, Thomas; Jernberg-Wiklund, Helena; Sehat, Bita; Larsson, Olle

    2011-01-14

    Research highlights: {yields} SUMOylation mediates nuclear translocation of IGF-1R which activates transcription. {yields} Here we show that nuclear IGF-1R over-accumulates in tumor cells. {yields} This requires overexpression of the receptor that is a common feature in tumor cells. {yields} An increased expression of the SUMO ligase Ubc9 seems to be an involved mechanism too. -- Abstract: The insulin-like growth factor 1 receptor (IGF-1R) plays crucial roles in tumor cell growth and is overexpressed in many cancers. IGF-1R's trans-membrane kinase signaling pathways have been well characterized. Very recently, we showed that SUMOylation mediates nuclear translocation of the IGF-1R, and that nuclear IGF-1R (nIGF-1R) binds to enhancer regions and activates transcription. We identified three lysine residues in the {beta}-subunit of the receptor and that mutation of these blocks nuclear translocation and gene activation. Furthermore, accumulation of nIGF-1R was proven strongly dependent on the specific SUMO-conjugating enzyme Ubc9. Here we show that nIGF-1R originates solely from the cell membrane and that phosphorylation of the core tyrosine residues of the receptor kinase is crucial for nuclear accumulation. We also compared the levels of nIGF-1R, measured as nuclear/membrane ratios, in tumor and normal cells. We found that the breast cancer cell line MCF-7 has 13-fold higher amounts of nIGF-1R than breast epithelial cells (IME) which showed only a small amount of nIGF-1R. In comparison, the total expression of IGF-1R was only 3.7- higher in MCF-7. Comparison of several other tumor and normal cell lines showed similar tumor cell over-accumulation of nIGF-1R, exceeding the total receptor expression substantially. Ectopic overexpression (>10-fold) of the receptor increased nIGF-1R in IME cells but not to that high level as in wild type MCF-7. The levels of Ubc9 were higher in all tumor cell lines, compared to the normal cells, and this probably contributes to over

  6. IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line

    PubMed Central

    Lin, Ta-Chin; Yen, Jui-Mei; Gong, Kun-Bing; Hsu, Teng-Tsao; Chen, Lih-Ren

    2003-01-01

    Background Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. Results In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). Conclusion IGF-1

  7. Protein restriction cycles reduce IGF-1 and phosphorylated Tau, and improve behavioral performance in an Alzheimer’s disease mouse model

    PubMed Central

    Parrella, Edoardo; Maxim, Tom; Maialetti, Francesca; Zhang, Lu; Wan, Junxiang; Wei, Min; Cohen, Pinchas; Fontana, Luigi; Longo, Valter D.

    2014-01-01

    Summary In laboratory animals, calorie restriction (CR) protects against aging, oxidative stress, and neurodegenerative pathologies. Reduced levels of growth hormone and IGF-1, which mediate some of the protective effects of CR, can also extend longevity and/or protect against age-related diseases in rodents and humans. However, severely restricted diets are difficult to maintain and are associated with chronically low weight and other major side effects. Here we show that 4 months of periodic protein restriction cycles (PRCs) with supplementation of nonessential amino acids in mice already displaying significant cognitive impairment and Alzheimer’s disease (AD)-like pathology reduced circulating IGF-1 levels by 30–70% and caused an 8-fold increase in IGFBP-1. Whereas PRCs did not affect the levels of β amyloid (Aβ), they decreased tau phosphorylation in the hippocampus and alleviated the age-dependent impairment in cognitive performance. These results indicate that periodic protein restriction cycles without CR can promote changes in circulating growth factors and tau phosphorylation associated with protection against age-related neuropathologies. PMID:23362919

  8. Increased linear bone growth by GH in the absence of SOCS2 is independent of IGF-1.

    PubMed

    Dobie, Ross; Ahmed, Syed F; Staines, Katherine A; Pass, Chloe; Jasim, Seema; MacRae, Vicky E; Farquharson, Colin

    2015-11-01

    Growth hormone (GH) signaling is essential for postnatal linear bone growth, but the relative importance of GHs actions on the liver and/or growth plate cartilage remains unclear. The importance of liver derived insulin like-growth factor-1 (IGF-1) for endochondral growth has recently been challenged. Here, we investigate linear growth in Suppressor of Cytokine Signaling-2 (SOCS2) knockout mice, which have enhanced growth despite normal systemic GH/IGF-1 levels. Wild-type embryonic ex vivo metatarsals failed to exhibit increased linear growth in response to GH, but displayed increased Socs2 transcript levels (P < 0.01). In the absence of SOCS2, GH treatment enhanced metatarsal linear growth over a 12 day period. Despite this increase, IGF-1 transcript and protein levels were not increased in response to GH. In accordance with these data, IGF-1 levels were unchanged in GH-challenged postnatal Socs2(-/-) conditioned medium despite metatarsals showing enhanced linear growth. Growth-plate Igf1 mRNA levels were not elevated in juvenile Socs2(-/-) mice. GH did however elevate IGF-binding protein 3 levels in conditioned medium from GH challenged metatarsals and this was more apparent in Socs2(-/-) metatarsals. GH did not enhance the growth of Socs2(-/-) metatarsals when the IGF receptor was inhibited, suggesting that IGF receptor mediated mechanisms are required. IGF-2 may be responsible as IGF-2 promoted metatarsal growth and Igf2 expression was elevated in Socs2(-/-) (but not WT) metatarsals in response to GH. These studies emphasise the critical importance of SOCS2 in regulating GHs ability to promote bone growth. Also, GH appears to act directly on the metatarsals of Socs2(-/-) mice, promoting growth via a mechanism that is independent of IGF-1.

  9. Disease tolerance mediated by commensal E. coli via inflammasome and IGF-1 signaling

    PubMed Central

    Palaferri Schieber, Alexandria M.; Lee, Yujung Michelle; Chang, Max W.; Leblanc, Mathias; Collins, Brett; Downes, Michael; Evans, Ronald M.; Ayres, Janelle S.

    2016-01-01

    Infections and inflammation can lead to cachexia and wasting of skeletal muscle and fat tissue by as yet poorly understood mechanisms. We observed that gut colonization of mice by a strain of Escherichia coli prevents wasting triggered by infections or physical damage to the intestine. During intestinal infection with the pathogen Salmonella Typhimurium or pneumonic infection with Burkholderia thailandensis, the presence of this E. coli did not alter changes in host metabolism, caloric uptake or inflammation, but instead sustained signaling of the IGF-1/PI3K/AKT pathway in skeletal muscle, required for prevention of muscle wasting. This effect was dependent on engagement of the NLRC4 inflammasome. Therefore, this commensal promotes tolerance to diverse diseases. PMID:26516283

  10. Doping with growth hormone/IGF-1, anabolic steroids or erythropoietin: is there a cancer risk?

    PubMed

    Tentori, Lucio; Graziani, Grazia

    2007-05-01

    Anabolic steroid and peptide hormones or growth factors are utilized to increase the performance of athletes of professional or amateur sports. Despite their well-documented adverse effects, the use of some of these agents has significantly grown and has been extended also to non-athletes with the aim to improve appearance or to counteract ageing. Pre-clinical studies and epidemiological observations in patients with an excess of hormone production or in patients chronically treated with hormones/growth factors for various pathologies have warned about the potential risk of cancer development and progression which may be also associated to the use of certain doping agents. Anabolic steroids have been described to provoke liver tumours; growth hormone or high levels of its mediator insulin-like growth factor-1 (IGF-1) have been associated with colon, breast, and prostate cancers. Actually, IGF-1 promotes cell cycle progression and inhibits apoptosis either by triggering other growth factors or by interacting with pathways which have an established role in carcinogenesis and cancer promotion. More recently, the finding that erythropoietin (Epo) may promote angiogenesis and inhibit apoptosis or modulate chemo- or radiosensitivity in cancer cells expressing the Epo receptor, raised the concern that the use of recombinant Epo to increase tissue oxygenation might favour tumour survival and aggressiveness. Cancer risk associated to doping might be higher than that of patients using hormones/growth factors as replacement therapy, since enormous doses are taken by the athletes often for a long period of time. Moreover, these substances are often used in combination with other licit or illicit drugs and this renders almost unpredictable all the possible adverse effects including cancer. Anyway, athletes should be made aware that long-term treatment with doping agents might increase the risk of developing cancer.

  11. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels.

    PubMed

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B; Marin de Evsikova, Caralina; Xing, Shuqin; Marion, Michael A; Bogue, Molly A; Mills, Kevin D; Peters, Luanne L; Bult, Carol J; Rosen, Clifford J; Sundberg, John P; Harrison, David E; Churchill, Gary A; Paigen, Beverly

    2009-06-01

    To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. Clinical assessments were carried out every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, more invasive measurements were carried out followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, the study design, median lifespans, and circulating insulin-like growth factor 1 (IGF1) levels at 6, 12, and 18 months are described for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with the median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with a median lifespan at 6 months (R = -0.33, P = 0.01). This correlation became stronger if the short-lived strains with a median lifespan < 600 days were removed from the analysis (R = -0.53, P < 0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan.

  12. Discovery of the first non-ATP competitive IGF-1R kinase inhibitors: advantages in comparison with competitive inhibitors.

    PubMed

    Lesuisse, Dominique; Mauger, Jacques; Nemecek, Conception; Maignan, Sébastien; Boiziau, Janine; Harlow, Greg; Hittinger, Augustin; Ruf, Swen; Strobel, Hartmut; Nair, Anil; Ritter, Kurt; Malleron, Jean-Luc; Dagallier, Anne; El-Ahmad, Youssef; Guilloteau, Jean-Pierre; Guizani, Houlfa; Bouchard, Hervé; Venot, Corinne

    2011-04-15

    A new series of IGF-1R inhibitors related to hydantoins were identified from a lead originating from HTS. Their noncompetitive property as well as their slow binding characteristics provided a series of compounds with unique selectivity and excellent cellular activities.

  13. Daucosterol protects neurons against oxygen-glucose deprivation/reperfusion-mediated injury by activating IGF1 signaling pathway.

    PubMed

    Jiang, Li-hua; Yuan, Xiao-lin; Yang, Nian-yun; Ren, Li; Zhao, Feng-ming; Luo, Ban-xin; Bian, Yao-yao; Xu, Jian-ya; Lu, Da-xiang; Zheng, Yuan-yuan; Zhang, Chuan-juan; Diao, Yuan-ming; Xia, Bao-mei; Chen, Gang

    2015-08-01

    We previously reported that daucosterol (a sterolin) up-regulates the expression of insulin-like growth factor I (IGF1)(1) protein in neural stem cells. In this study, we investigated the effects of daucosterol on the survival of cultured cortical neurons after neurons were subjected to oxygen and glucose deprivation and simulated reperfusion (OGD/R)(2), and determined the corresponding molecular mechanism. The results showed that post-treatment of daucosterol significantly reduced neuronal loss, as well as apoptotic rate and caspase-3 activity, displaying the neuroprotective activity. We also found that daucosterol increased the expression level of IGF1 protein, diminished the down-regulation of p-AKT(3) and p-GSK-3β(4), thus activating the AKT(5) signal pathway. Additionally, it diminished the down-regulation of the anti-apoptotic proteins Mcl-1(6) and Bcl-2(7), and decreased the expression level of the pro-apoptotic protein Bax(8), thus raising the ratio of Bcl-2/Bax. The neuroprotective effect of daucosterol was inhibited in the presence of picropodophyllin (PPP)(9), the inhibitor of insulin-like growth factor I receptors (IGF1R)(10). Our study provided information about daucosterol as an efficient and inexpensive neuroprotectants, to which the IGF1-like activity of daucosterol contributes. Daucosterol could be potentially developed as a medicine for ischemic stroke treatment.

  14. Effect of Taekwondo Training on Physical Fitness and Growth Index According to IGF-1 Gene Polymorphism in Children

    PubMed Central

    Lee, Bonghan

    2015-01-01

    This study analyzed the effect of regular Taekwondo training for 16 weeks on physical fitness and growth index depending on different IGF-1 gene polymorphisms. The subjects of the study were 44 male students who were 8 year years old. The IGF-1 gene showed the highest frequency of 18 CA repeat (190 bp) in 50% of subjects, and was found in the homozygote (n=11), heterozygote (n=22) and non-carriers (n=11). The results of the physical fitness and growth index among the gene polymorphism groups indicated no significant differences but the expected height of the non-carrier group was significantly high (p<0.05). After Taekwondo training, the homozygote group and the non-carrier groups demonstrated significant (p<0.05) increase in grip strength and in time in the standing with one leg while closing eyes test, respectively. Only the homozygote group had a significant (p< 0.05) increase in thigh circumference. IGF-1 concentration significantly (p<0.05) increased in the heterozygote group, while HOMA-IR significantly (p<0.05) decreased in the homozygote group. Furthermore, there was a significant (p<0.05) decrease in glucose in both the homozygote and the non-carriers groups. The difference between physical fitness and growth index depending on the IGF-1 gene polymorphism after Taekwondo training did not show consistent impact. PMID:26170738

  15. IGF-1 receptor deficiency in thyrocytes impairs thyroid hormone secretion and completely inhibits TSH-stimulated goiter.

    PubMed

    Ock, Sangmi; Ahn, Jihyun; Lee, Seok Hong; Kang, Hyun; Offermanns, Stefan; Ahn, Hwa Young; Jo, Young Suk; Shong, Minho; Cho, Bo Youn; Jo, Daewoong; Abel, E Dale; Lee, Tae Jin; Park, Woo Jin; Lee, In-Kyu; Kim, Jaetaek

    2013-12-01

    Although thyroid-stimulating hormone (TSH) is known to be a major regulator of thyroid hormone biosynthesis and thyroid growth, insulin-like growth factor 1 (IGF-1) is required for mediating thyrocyte growth in concert with TSH in vitro. We generated mice with thyrocyte-selective ablation of IGF-1 receptor (TIGF1RKO) to explore the role of IGF-1 receptor signaling on thyroid function and growth. In 5-wk-old TIGF1RKO mice, serum thyroxine (T4) concentrations were decreased by 30% in concert with a 43% down-regulation of the monocarboxylate transporter 8 (MCT8), which is involved in T4 secretion. Despite a 3.5-fold increase in circulating concentrations of TSH, thyroid architecture and size were normal. Furthermore, thyrocyte area was increased by 40% in WT thyroids after 10 d TSH injection, but this effect was absent in TSH-injected TIGF1RKO mice. WT mice treated with methimazole and sodium perchlorate for 2 or 6 wk exhibited pronounced goiter development (2.0 and 5.4-fold, respectively), but in TIGF1RKO mice, goiter development was completely abrogated. These data reveal an essential role for IGF-1 receptor signaling in the regulation of thyroid function and TSH-stimulated goitrogenesis.

  16. Overexpression of IGF2R and IGF1R mRNA in SCNT-produced goats survived to adulthood.

    PubMed

    Xing, Baosong; Xu, Yinxue; Cheng, Yong; Liu, Honglin; Du, Miao

    2007-08-01

    The procedure of somatic cell nuclear transfer (SCNT) is likely to affect the expression level of growth-related genes especially imprinting genes. In this study, expressions of growth-related genes including three imprinting genes (H19, IGF2, and IGF2R) and four non-imprinting genes (IGF1, IGF1R, GHR, and GHSR) in adult nuclear transferred (NT) goats were investigated by real-time PCR. The expressions of these genes in adult clones were found largely normal, but IGF2R and IGF1R were more highly expressed in cloned goats than in non-NT goats (P < 0.01). Analysis on mono-allelic expression pattern of imprinting genes indicated that mono-allelic expression patterns of H19 and IGF2 in cloned goats were similar to that in non-NT goats. In addition, the sequence of goat IGF2 gene and the putative amino acid sequence were obtained. The 986 nucleotide cDNA of goat IGF2 gene contained an open-reading frame of 540 nucleotides coding for 179 amino acids. Both cDNA sequence and amino acid sequence of IGF2 in goat showed their higher homology with that in sheep than in cattle; the partial cDNA fragments of H19, IGF2R, GHSR, IGF1R, and GHR in goat were also cloned and sequenced, which shared higher sequence identities with those in sheep than in cattle.

  17. Effect of Taekwondo Training on Physical Fitness and Growth Index According to IGF-1 Gene Polymorphism in Children.

    PubMed

    Lee, Bonghan; Kim, Kijin

    2015-07-01

    This study analyzed the effect of regular Taekwondo training for 16 weeks on physical fitness and growth index depending on different IGF-1 gene polymorphisms. The subjects of the study were 44 male students who were 8 year years old. The IGF-1 gene showed the highest frequency of 18 CA repeat (190 bp) in 50% of subjects, and was found in the homozygote (n=11), heterozygote (n=22) and non-carriers (n=11). The results of the physical fitness and growth index among the gene polymorphism groups indicated no significant differences but the expected height of the non-carrier group was significantly high (p<0.05). After Taekwondo training, the homozygote group and the non-carrier groups demonstrated significant (p<0.05) increase in grip strength and in time in the standing with one leg while closing eyes test, respectively. Only the homozygote group had a significant (p< 0.05) increase in thigh circumference. IGF-1 concentration significantly (p<0.05) increased in the heterozygote group, while HOMA-IR significantly (p<0.05) decreased in the homozygote group. Furthermore, there was a significant (p<0.05) decrease in glucose in both the homozygote and the non-carriers groups. The difference between physical fitness and growth index depending on the IGF-1 gene polymorphism after Taekwondo training did not show consistent impact.

  18. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels

    PubMed Central

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B.; de Evsikova, Caralina Marin; Xing, Shuqin; Marion, Michael A.; Bogue, Molly A.; Mills, Kevin D.; Peters, Luanne L.; Bult, Carol J.; Rosen, Clifford J.; Sundberg, John P.; Harrison, David E.; Churchill, Gary A.; Paigen, Beverly

    2009-01-01

    Summary To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. We carried out clinical assessments every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, we carried out more invasive measurements followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, we describe the study design, median lifespans, and circulating IGF1 levels at 6, 12 and 18 months for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with median lifespan at 6 months (R=−0.33, P=0.01). This correlation became stronger if the short-lived strains with a median lifespan<600 days were removed from the analysis (R=−0.53, P<0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan. PMID:19627267

  19. Dynamic compression of rabbit adipose-derived stem cells transfected with insulin-like growth factor 1 in chitosan/gelatin scaffolds induces chondrogenesis and matrix biosynthesis.

    PubMed

    Li, Jianjun; Zhao, Qun; Wang, Enbo; Zhang, Chuanhui; Wang, Guangbin; Yuan, Quan

    2012-05-01

    Articular cartilage is routinely subjected to mechanical forces and growth factors. Adipose-derived stem cells (ASCs) are multi-potent adult stem cells and capable of chondrogenesis. In the present study, we investigated the comparative and interactive effects of dynamic compression and insulin-like growth factor-I (IGF-I) on the chondrogenesis of rabbit ASCs in chitosan/gelatin scaffolds. Rabbit ASCs with or without a plasmid overexpressing of human IGF-1 were cultured in chitosan/gelatin scaffolds for 2 days, then subjected to cyclic compression with 5% strain and 1 Hz for 4 h per day for seven consecutive days. Dynamic compression induced chondrogenesis of rabbit ASCs by activating calcium signaling pathways and up-regulating the expression of Sox-9. Dynamic compression plus IGF-1 overexpression up-regulated expression of chondrocyte-specific extracellular matrix genes including type II collagen, Sox-9, and aggrecan with no effect on type X collagen expression. Furthermore, dynamic compression and IGF-1 expression promoted cellular proliferation and the deposition of proteoglycan and collagen. Intracellular calcium ion concentration and peak currents of Ca(2+) ion channels were consistent with chondrocytes. The tissue-engineered cartilage from this process had excellent mechanical properties. When applied together, the effects achieved by the two stimuli (dynamic compression and IGF-1) were greater than those achieved by either stimulus alone. Our results suggest that dynamic compression combined with IGF-1 overexpression might benefit articular cartilage tissue engineering in cartilage regeneration.

  20. Prophylactic Subacute Administration of Zinc Increases CCL2, CCR2, FGF2, and IGF-1 Expression and Prevents the Long-Term Memory Loss in a Rat Model of Cerebral Hypoxia-Ischemia

    PubMed Central

    Blanco-Alvarez, Victor Manuel; Soto-Rodriguez, Guadalupe; Gonzalez-Barrios, Juan Antonio; Martinez-Fong, Daniel; Brambila, Eduardo; Torres-Soto, Maricela; Aguilar-Peralta, Ana Karina; Gonzalez-Vazquez, Alejandro; Tomás-Sanchez, Constantino; Limón, I. Daniel; Eguibar, Jose R.; Ugarte, Araceli; Hernandez-Castillo, Jeanett; Leon-Chavez, Bertha Alicia

    2015-01-01

    Prophylactic subacute administration of zinc decreases lipoperoxidation and cell death following a transient cerebral hypoxia-ischemia, thus suggesting neuroprotective and preconditioning effects. Chemokines and growth factors are also involved in the neuroprotective effect in hypoxia-ischemia. We explored whether zinc prevents the cerebral cortex-hippocampus injury through regulation of CCL2, CCR2, FGF2, and IGF-1 expression following a 10 min of common carotid artery occlusion (CCAO). Male rats were grouped as follows: (1) Zn96h, rats injected with ZnCl2 (one dose every 24 h during four days); (2) Zn96h + CCAO, rats treated with ZnCl2 before CCAO; (3) CCAO, rats with CCAO only; (4) Sham group, rats with mock CCAO; and (5) untreated rats. The cerebral cortex-hippocampus was dissected at different times before and after CCAO. CCL2/CCR2, FGF2, and IGF-1 expression was assessed by RT-PCR and ELISA. Learning in Morris Water Maze was achieved by daily training during 5 days. Long-term memory was evaluated on day 7 after learning. Subacute administration of zinc increased expression of CCL2, CCR2, FGF2, and IGF-1 in the early and late phases of postreperfusion and prevented the CCAO-induced memory loss in the rat. These results might be explained by the induction of neural plasticity because of the expression of CCL2 and growth factors. PMID:26355725

  1. ROS production as a common mechanism of ENaC regulation by EGF, insulin, and IGF-1.

    PubMed

    Ilatovskaya, Daria V; Pavlov, Tengis S; Levchenko, Vladislav; Staruschenko, Alexander

    2013-01-01

    The epithelial Na(+) channel (ENaC) is a key transporter participating in the fine tuning of Na(+) reabsorption in the nephron. ENaC activity is acutely upregulated by epidermal growth factor (EGF), insulin, and insulin-like growth factor-1 (IGF-1). It was also proposed that reactive oxygen species (ROS) have a stimulatory effect on ENaC. Here we studied whether effects of EGF, insulin, and IGF-1 correlate with ROS production in the mouse cortical collecting duct (mpkCCD(c14)) cells. Western blotting confirmed the expression of the NADPH oxidase complex subunits in these cells. Treatment of mpkCCD(c14) cells with EGF, insulin, or IGF-1 evoked an increase in ROS production as measured by CM-H(2)DCF-DA fluorescence. ROS production caused by a xanthine-xanthine oxidase reaction also resulted in a significant elevation in short-circuit current through the mpkCCD(c14) monolayer. Transepithelial current measurements showed an acute increase of amiloride-sensitive current through the mpkCCD(c14) monolayer in response to EGF, insulin, or IGF-1. Pretreatment with the nonselective NADPH oxidase activity inhibitor apocynin blunted both ROS production and increase in ENaC-mediated current in response to these drugs. To further test whether NADPH oxidase subunits are involved in the effect of EGF, we used a stable M-1 cell line with a knockdown of Rac1, which is one of the key subunits of the NADPH oxidase complex, and measured amiloride-sensitive currents in response to EGF. In contrast to control cells, EGF had no effect in Rac1 knockdown cells. We hypothesize that EGF, insulin, and IGF-1 have a common stimulatory effect on ENaC mediated by ROS production.

  2. Something old, something new and something borrowed: emerging paradigm of insulin-like growth factor type 1 receptor (IGF-1R) signaling regulation.

    PubMed

    Girnita, Leonard; Worrall, Claire; Takahashi, Shin-Ichiro; Seregard, Stefan; Girnita, Ada

    2014-07-01

    The insulin-like growth factor type 1 receptor (IGF-1R) plays a key role in the development and progression of cancer; however, therapeutics targeting it have had disappointing results in the clinic. As a receptor tyrosine kinase (RTK), IGF-1R is traditionally described as an ON/OFF system, with ligand stabilizing the ON state and exclusive kinase-dependent signaling activation. Newly added to the traditional model, ubiquitin-mediated receptor downregulation and degradation was originally described as a response to ligand/receptor interaction and thus inseparable from kinase signaling activation. Yet, the classical model has proven over-simplified and insufficient to explain experimental evidence accumulated over the last decade, including kinase-independent signaling, unbalanced signaling, or dissociation between signaling and receptor downregulation. Based on the recent findings that IGF-1R "borrows" components of G-protein coupled receptor (GPCR) signaling, including β-arrestins and G-protein-related kinases, we discuss the emerging paradigm for the IGF-1R as a functional RTK/GPCR hybrid, which integrates the kinase signaling with the IGF-1R canonical GPCR characteristics. The contradictions to the classical IGF-1R signaling concept as well as the design of anti-IGF-1R therapeutics treatment are considered in the light of this paradigm shift and we advocate recognition of IGF-1R as a valid target for cancer treatment.

  3. The dipeptide Pro-Asp promotes IGF-1 secretion and expression in hepatocytes by enhancing JAK2/STAT5 signaling pathway.

    PubMed

    Wang, Songbo; Wang, Guoqing; Zhang, Mengyuan; Zhuang, Lu; Wan, Xiaojuan; Xu, Jingren; Wang, Lina; Zhu, Xiaotong; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Shu, Gang; Jiang, Qingyan

    2016-11-15

    It has been implicated that IGF-1 secretion can be regulated by dietary protein. However, whether the dipeptides, one of digested products of dietary protein, have influence on IGF-1 secretion remain largely unknown. Our study aimed to investigate the effects of the dipeptide Pro-Asp on IGF-1 secretion and expression in hepatocytes and to explore the possible underlying mechanisms. Our findings demonstrated that Pro-Asp promoted the secretion and gene expression of IGF-1 in HepG2 cells and primary porcine hepatocytes. Meanwhile, Pro-Asp activated the ERK and Akt signaling pathways, downstream of IGF-1. In addition, Pro-Asp enhanced GH-mediated JAK2/STAT5 signaling pathway, while inhibition of JAK2/STAT5 blocked the promotive effect of Pro-Asp on IGF-1 secretion and expression. Moreover, acute injection of Pro-Asp stimulated IGF-1 expression and activated JAK2/STAT5 signaling pathway in mice liver. Together, these results suggested that the dipeptide Pro-Asp promoted IGF-1 secretion and expression in hepatocytes by enhancing GH-mediated JAK2/STAT5 signaling pathway.

  4. Insulin-like Growth Factor-1 (IGF-1): Demographic, Clinical and Laboratory Data in 120 Consecutive Adult Patients with Thalassaemia Major

    PubMed Central

    De Sanctis, Vincenzo; Soliman, Ashraf T; Candini, Giancarlo; Yassin, Mohamed; Raiola, Giuseppe; Galati, Maria Concetta; Elalaily, Rania; Elsedfy, Heba; Skordis, Nicos; Garofalo, Piernicola; Anastasi, Salvatore; Campisi, Saveria; Karimi, Mehran; Kattamis, Christos; Canatan, Duran; Kilinc, Yurdanur; Sobti, Praveen; Fiscina, Bernadette; El Kholy, Mohamed

    2014-01-01

    Introduction IGF-1 deficiency in TM patients in children and adolescents has been attributed to chronic anemia and hypoxia, chronic liver disease, iron overload and other associated endocrinopathies, e.g. growth hormone deficiency (GHD). Few data are available in the literature regarding adult TM patients and growth disorders. The aim of this study was to measure IGF-1 values and other clinical data in a large number of adult patients with TM to evaluate the possible relationships between them. Patients and Methods A cohort of 120 adult patients with TM was studied for plasma levels of IGF-1. Plasma total IGF-1 was determined by chemiluminescent immunometric assay (CLIA) method. In eleven patients (3 females) the GH response during glucagon stimulation test (GST) was also evaluated. Results Fifty percent of patients (33 males and 27 females) had IGF-1 levels <- 2 SDs below normative values for healthy subjects matched for age and sex. In these patients endocrine complications and elevations of aminotransferases (ALT) were more common compared to TM patients with IGF1 > -2SDs. In multivariate regression analyses, height, weight, BMI, serum ferritin, ALT, HCV serology and left ventricular ejection fraction (LVEF) were not significantly related to IGF-1, but a significant correlation was found in females between HCV-RNA positivity and IGF-1, ALT and serum ferritin. AGHD was diagnosed in 6 (4 males) out of 11 patients (54.5%) who had glucagon stimulation tests and in 5 out of 8 (62.5%) with IGF-1 <-2SD. The mean age of patients with GHD was 39.3 years (range: 25–49 years, median: 39 years) versus 35.8 years (range: 27–45 years, median: 37.5 years) in non-GHD patients. A positive correlation between GH peak after GST and IGF-1 level was found (r: 0.6409; p: < 0.05). Conclusions In 50% of TM patients the IGF-1 levels were 2SDs below average values for healthy individuals. IGF-1 deficiency was more common in TM patients with associated endocrine complications, and a

  5. Sodium arsenite represses the expression of myogenin in C2C12 mouse myoblast cells through histone modifications and altered expression of Ezh2, Glp, and Igf-1

    SciTech Connect

    Hong, Gia-Ming

    2012-05-01

    Arsenic is a toxicant commonly found in water systems and chronic exposure can result in adverse developmental effects including increased neonatal death, stillbirths, and miscarriages, low birth weight, and altered locomotor activity. Previous studies indicate that 20 nM sodium arsenite exposure to C2C12 mouse myocyte cells delayed myoblast differentiation due to reduced myogenin expression, the transcription factor that differentiates myoblasts into myotubes. In this study, several mechanisms by which arsenic could alter myogenin expression were examined. Exposing differentiating C2C12 cells to 20 nM arsenic increased H3K9 dimethylation (H3K9me2) and H3K9 trimethylation (H3K9me3) by 3-fold near the transcription start site of myogenin, which is indicative of increased repressive marks, and reduced H3K9 acetylation (H3K9Ac) by 0.5-fold, indicative of reduced permissive marks. Protein expression of Glp or Ehmt1, a H3-K9 methyltransferase, was also increased by 1.6-fold in arsenic-exposed cells. In addition to the altered histone remodeling status on the myogenin promoter, protein and mRNA levels of Igf-1, a myogenic growth factor, were significantly repressed by arsenic exposure. Moreover, a 2-fold induction of Ezh2 expression, and an increased recruitment of Ezh2 (3.3-fold) and Dnmt3a (∼ 2-fold) to the myogenin promoter at the transcription start site (− 40 to + 42), were detected in the arsenic-treated cells. Together, we conclude that the repressed myogenin expression in arsenic-exposed C2C12 cells was likely due to a combination of reduced expression of Igf-1, enhanced nuclear expression and promoter recruitment of Ezh2, and altered histone remodeling status on myogenin promoter (− 40 to + 42). -- Highlights: ► Igf-1 expression is decreased in C2C12 cells after 20 nM arsenite exposure. ► Arsenic exposure alters histone remodeling on the myogenin promoter. ► Glp expression, a H3–K9 methyltransferase, was increased in arsenic-exposed cells. ► Ezh2

  6. IGF-1 degradation by mouse mast cell protease 4 promotes cell death and adverse cardiac remodeling days after a myocardial infarction

    PubMed Central

    Tejada, Thor; Tan, Lin; Torres, Rebecca A.; Calvert, John W.; Lambert, Jonathan P.; Zaidi, Madiha; Husain, Murtaza; Berce, Maria D.; Naib, Hussain; Pejler, Gunnar; Abrink, Magnus; Graham, Robert M.; Lefer, David J.; Naqvi, Nawazish; Husain, Ahsan

    2016-01-01

    Heart disease is a leading cause of death in adults. Here, we show that a few days after coronary artery ligation and reperfusion, the ischemia-injured heart elaborates the cardioprotective polypeptide, insulin-like growth factor-1 (IGF-1), which activates IGF-1 receptor prosurvival signaling and improves cardiac left ventricular systolic function. However, this signaling is antagonized by the chymase, mouse mast cell protease 4 (MMCP-4), which degrades IGF-1. We found that deletion of the gene encoding MMCP-4 (Mcpt4), markedly reduced late, but not early, infarct size by suppressing IGF-1 degradation and, consequently, diminished cardiac dysfunction and adverse structural remodeling. Our findings represent the first demonstration to our knowledge of tissue IGF-1 regulation through proteolytic degradation and suggest that chymase inhibition may be a viable therapeutic approach to enhance late cardioprotection in postischemic heart disease. PMID:27274047

  7. Erythropoietin and IGF-1 signaling synchronize cell proliferation and maturation during erythropoiesis

    PubMed Central

    Kadri, Zahra; Lefevre, Carine; Goupille, Olivier; Penglong, Tipparat; Granger-Locatelli, Marine; Fucharoen, Suthat; Maouche-Chretien, Leila; Leboulch, Philippe; Chretien, Stany

    2015-01-01

    Tight coordination of cell proliferation and differentiation is central to red blood cell formation. Erythropoietin controls the proliferation and survival of red blood cell precursors, while variations in GATA-1/FOG-1 complex composition and concentrations drive their maturation. However, clear evidence of cross-talk between molecular pathways is lacking. Here, we show that erythropoietin activates AKT, which phosphorylates GATA-1 at Ser310, thereby increasing GATA-1 affinity for FOG-1. In turn, FOG-1 displaces pRb/E2F-2 from GATA-1, ultimately releasing free, proproliferative E2F-2. Mice bearing a Gata-1S310A mutation suffer from fatal anemia when a compensatory pathway for E2F-2 production involving insulin-like growth factor-1 (IGF-1) signaling is simultaneously abolished. In the context of the GATA-1V205G mutation resulting in lethal anemia, we show that the Ser310 cannot be phosphorylated and that constitutive phosphorylation at this position restores partial erythroid differentiation. This study sheds light on the GATA-1 pathways that synchronize cell proliferation and differentiation for tissue homeostasis. PMID:26680303

  8. Reduced insulin/IGF-1 signaling restores germ cell immortality to Caenorhabditis elegans Piwi mutants.

    PubMed

    Simon, Matt; Sarkies, Peter; Ikegami, Kohta; Doebley, Anna-Lisa; Goldstein, Leonard D; Mitchell, Jacinth; Sakaguchi, Aisa; Miska, Eric A; Ahmed, Shawn

    2014-05-08

    Defects in the Piwi/piRNA pathway lead to transposon desilencing and immediate sterility in many organisms. We found that the C. elegans Piwi mutant prg-1 became sterile after growth for many generations. This phenotype did not occur for RNAi mutants with strong transposon-silencing defects and was separable from the role of PRG-1 in transgene silencing. Brief periods of starvation extended the transgenerational lifespan of prg-1 mutants by stimulating the DAF-16/FOXO longevity transcription factor. Constitutive activation of DAF-16 via reduced daf-2 insulin/IGF-1 signaling immortalized prg-1 strains via RNAi proteins and histone H3 lysine 4 demethylases. In late-generation prg-1 mutants, desilencing of repetitive segments of the genome occurred, and silencing of repetitive loci was restored in prg-1; daf-2 mutants. This study reveals an unexpected interface between aging and transgenerational maintenance of germ cells, where somatic longevity is coupled to a genome-silencing pathway that promotes germ cell immortality in parallel to the Piwi/piRNA system.

  9. Rates of molecular evolution vary in vertebrates for insulin-like growth factor-1 (IGF-1), a pleiotropic locus that regulates life history traits.

    PubMed

    Sparkman, Amanda M; Schwartz, Tonia S; Madden, Jill A; Boyken, Scott E; Ford, Neil B; Serb, Jeanne M; Bronikowski, Anne M

    2012-08-01

    Insulin-like growth factor-1 (IGF-1) is a member of the vertebrate insulin/insulin-like growth factor/relaxin gene family necessary for growth, reproduction, and survival at both the cellular and organismal level. Its sequence, protein structure, and function have been characterized in mammals, birds, and fish; however, a notable gap in our current knowledge of the function of IGF-1 and its molecular evolution is information in ectothermic reptiles. To address this disparity, we sequenced the coding region of IGF-1 in 11 reptile species-one crocodilian, three turtles, three lizards, and four snakes. Complete sequencing of the full mRNA transcript of a snake revealed the Ea-isoform, the predominant isoform of IGF-1 also reported in other vertebrate groups. A gene tree of the IGF-1 protein-coding region that incorporated sequences from diverse vertebrate groups showed similarity to the species phylogeny, with the exception of the placement of Testudines as sister group to Aves, due to their high nucleotide sequence similarity. In contrast, long-branch lengths indicate more rapid divergence in IGF-1 among lizards and snakes. Additionally, lepidosaurs (i.e., lizards and snakes) had higher rates of non-synonymous:synonymous substitutions (dN/dS) relative to archosaurs (i.e., birds and crocodilians) and turtles. Tests for positive selection on specific codons within branches and evaluation of the changes in the amino acid properties, suggested positive selection in lepidosaurs on the C domain of IGF-1, which is involved in binding affinity to the IGF-1 receptor. Predicted structural changes suggest that major alterations in protein structure and function may have occurred in reptiles. These data propose new insights into the molecular co-evolution of IGF-1 and its receptors, and ultimately the evolution of IGF-1's role in regulating life-history traits across vertebrates.

  10. The role of insulin-like growth factor-1 (IGF-1) in growth and reproduction in female brown house snakes (Lamprophis fuliginosus).

    PubMed

    Sparkman, A M; Byars, D; Ford, N B; Bronikowski, A M

    2010-09-15

    Insulin-like growth factor-1 (IGF-1) is a peptide hormone critically involved in the regulation of key life-history traits such as growth and reproduction. Its structure and function are well-characterized among diverse mammal, fish, and bird species; however, little is known regarding the activities of IGF-1 in non-avian reptiles, particularly snakes and lizards. Nevertheless, several unique characteristics of reptiles, such as high metabolic flexibility and remarkable diversity in life-history strategy, suggest that they are of great interest in the study of endocrinological mechanisms underlying the regulation and evolution of life-history traits. Here we test for a relationship between IGF-1 and individual feeding rate, growth rate and reproductive stage in lab-reared female offspring of wild-caught oviparous house snakes, Lamprophis fuliginosus. We confirm a positive correlation between IGF-1 and both feeding and growth rates in sexually immature snakes, similar to that reported in other taxa. We also show a family effect on IGF-1, suggesting that IGF-1 levels may be heritable in these snakes, and serve as an important target of selection to produce divergent life-history strategies. Furthermore, we provide evidence that suggests that IGF-1 may peak rapidly after first mating, and subsequently decline prior to egg-laying, a phenomenon not previously reported in other taxa. These findings suggest that further comparative study of IGF-1 in snakes may reveal both the extent to which IGF-1 function is conserved across major taxonomic groups, as well as novel and intriguing roles for IGF-1 in the regulation of reproductive activities.

  11. Differential effects of IGF-1 deficiency during the life span on structural and biomechanical properties in the tibia of aged mice.

    PubMed

    Ashpole, Nicole M; Herron, Jacquelyn C; Estep, Patrick N; Logan, Sreemathi; Hodges, Erik L; Yabluchanskiy, Andriy; Humphrey, Mary Beth; Sonntag, William E

    2016-04-01

    Advanced aging is associated with the loss of structural and biomechanical properties in bones, which increases the risk for bone fracture. Aging is also associated with reductions in circulating levels of the anabolic signaling hormone, insulin-like growth factor (IGF)-1. While the role of IGF-1 in bone development has been well characterized, the impact of the age-related loss of IGF-1 on bone aging remains controversial. Here, we describe the effects of reducing IGF-1 at multiple time points in the mouse life span--early in postnatal development, early adulthood, or late adulthood on tibia bone aging in both male and female igf (f/f) mice. Bone structure was analyzed at 27 months of age using microCT. We find that age-related reductions in cortical bone fraction, cortical thickness, and tissue mineral density were more pronounced when IGF-1 was reduced early in life and not in late adulthood. Three-point bone bending assays revealed that IGF-1 deficiency early in life resulted in reduced maximum force, maximum bending moment, and bone stiffness in aged males and females. The effects of IGF-1 on bone aging are microenvironment specific, as early-life loss of IGF-1 resulted in decreased cortical bone structure and strength along the diaphysis while significantly increasing trabecular bone fraction and trabecular number at the proximal metaphysis. The increases in trabecular bone were limited to males, as early-life loss of IGF-1 did not alter bone fraction or number in females. Together, our data suggest that the age-related loss of IGF-1 influences tibia bone aging in a sex-specific, microenvironment-specific, and time-dependent manner.

  12. Expression characteristics of proteins of IGF-1R, p-Akt, and survivin in papillary thyroid carcinoma patients with type 2 diabetes mellitus

    PubMed Central

    Yan, Yuerong; Hu, Fengqiu; Wu, Weilu; Ma, Ruiting; Huang, Hui

    2017-01-01

    Abstract Type 2 diabetes mellitus (T2DM) is related to increased risk of papillary thyroid carcinoma (PTC). Insulin-like growth factor-1 receptor (IGF-1R) is increased in patients with T2DM. The increased IGF-1R may be responsible for the development of PTC. In this study, we investigated the expression of phosphorylation of Akt (p-Akt)/survivin pathway activated by IGF-1R in PTC subjects with and without diabetes. Clinicopathological data of 20 PTC patients with T2DM were retrospectively analyzed and compared with those of 21 PTC subjects without diabetes. Meanwhile, IGF-1R, p-Akt, and survivin expressions of PTC tissues were detected by immunohistochemical staining. The immunohistochemical results found that the expression level of IGF-1R was significantly higher in diabetic PTC patients than that in nondiabetic PTC patients (P < 0.05). However, no significant differences of p-Akt and survivin expression were found between PTC patients with T2DM and PTC patients without T2DM. In addition, among 20 PTC patients with T2DM, subgroup analysis showed that the ratio of tumor size >10 mm was significantly higher in IGF-1R moderate to strong expression group than that in IGF-1R negative to weak expression group (P < 0.05). IGF-1R expression level was higher in PTC patients with T2DM, and the increased IGF-1R expression was associated with lager tumor size. IGF-1R may play an important role in carcinogenesis and tumor growth in PTC patients with T2DM. PMID:28328831

  13. Eighteen Insulin-like Growth Factor (IGF) pathway genes, circulating levels of IGF-1 and its binding protein (IGFBP-3), and risk of prostate and breast cancer

    PubMed Central

    Gu, Fangyi; Schumacher, Fredrick R.; Canzian, Federico; Allen, Naomi E.; Albanes, Demetrius; Berg, Christine D; Berndt, Sonja I.; Boeing, Heiner; Bueno-de-Mesquita, H. Bas; Buring, Julie E.; Chabbert-Buffet, Nathalie; Chanock, Stephen J.; Clavel-Chapelon, Françoise; Dumeaux, Vanessa; Gaziano, J. Michael; Giovannucci, Edward L.; Haiman, Christopher A.; Hankinson, Susan E.; Hayes, Richard B.; Henderson, Brian E.; Hunter, David J.; Hoover, Robert N.; Johansson, Mattias; Key, Timothy J.; Khaw, Kay-Tee; Kolonel, Laurence N.; Lagiou, Pagona; Lee, I-Min; LeMarchand, Loic; Lund, Eiliv; Ma, Jing; Onland-Moret, N. Charlotte; Overvad, Kim; Rodriguez, Laudina; Sacerdote, Carlotta; Sánchez, Maria-José; Stampfer, Meir J.; Stattin, Pär; Stram, Daniel O.; Thomas, Gilles; Thun, Michael J.; Tjønneland, Anne; Trichopoulos, Dimitrios; Tumino, Rosario; Virtamo, Jarmo; Weinstein, Stephanie J.; Willett, Walter C.; Yeager, Meredith; Zhang, Shumin M.; Kaaks, Rudolf; Riboli, Elio; Ziegler, Regina G.; Kraft, Peter

    2010-01-01

    Background Circulating levels of insulin-like growth factor I (IGF-1) and its main binding protein, IGF binding protein 3 (IGFBP-3), have been associated with risk of several types of cancer. Heritable factors explain up to 60% of the variation in IGF-1 and IGFBP-3 in studies of adult twins. Methods We systematically examined common genetic variation in 18 genes in the IGF signaling pathway for associations with circulating levels of IGF-1 and IGFBP-3. A total of 302 single nucleotide polymorphisms (SNPs) were genotyped in over 5500 Caucasian men and 5500 Caucasian women from the Breast and Prostate Cancer Cohort Consortium (BPC3). Results After adjusting for multiple testing, SNPs in the IGF1 and SSTR5 genes were significantly associated with circulating IGF-1 (p<2.1×10−4); SNPs in the IGFBP3 and IGFALS genes were significantly associated with circulating IGFBP-3. Multi-SNP models explained R2=0.62% of the variation in circulating IGF-1 and 3.9% of the variation in circulating IGFBP-3. We saw no significant association between these multi-SNP predictors of circulating IGF-1 or IGFBP-3 and risk of prostate or breast cancers. Conclusion Common genetic variation in the IGF1 and SSTR5 genes appears to influence circulating IGF-1 levels, and variation in IGFBP3 and IGFALS appears to influence circulating IGFBP-3. However, these variants explain only a small percentage of the variation in circulating IGF-1 and IGFBP-3 in Caucasian men and women. Impact Further studies are needed to explore contributions from other genetic factors such as rare variants in these genes and variation outside of these genes. PMID:20810604

  14. IGF-1 Induces GHRH Neuronal Axon Elongation during Early Postnatal Life in Mice

    PubMed Central

    Clemessy, Maud; Heurtier, Victor; Ledent, Tatiana; Robinson, Iain C.; Mollard, Patrice; Epelbaum, Jacques; Meaney, Michael J.; Garel, Sonia; Le Bouc, Yves; Kappeler, Laurent

    2017-01-01

    Nutrition during the perinatal period programs body growth. Growth hormone (GH) secretion from the pituitary regulates body growth and is controlled by Growth Hormone Releasing Hormone (GHRH) neurons located in the arcuate nucleus of the hypothalamus. We observed that dietary restriction during the early postnatal period (i.e. lactation) in mice influences postnatal growth by permanently altering the development of the somatotropic axis in the pituitary gland. This alteration may be due to a lack of GHRH signaling during this critical developmental period. Indeed, underfed pups showed decreased insulin-like growth factor I (IGF-I) plasma levels, which are associated with lower innervation of the median eminence by GHRH axons at 10 days of age relative to normally fed pups. IGF-I preferentially stimulated axon elongation of GHRH neurons in in vitro arcuate explant cultures from 7 day-old normally fed pups. This IGF-I stimulating effect was selective since other arcuate neurons visualized concomitantly by neurofilament labeling, or AgRP immunochemistry, did not significantly respond to IGF-I stimulation. Moreover, GHRH neurons in explants from age-matched underfed pups lost the capacity to respond to IGF-I stimulation. Molecular analyses indicated that nutritional restriction was associated with impaired activation of AKT. These results highlight a role for IGF-I in axon elongation that appears to be cell selective and participates in the complex cellular mechanisms that link underfeeding during the early postnatal period with programming of the growth trajectory. PMID:28076448

  15. STAT6-Dependent Collagen Synthesis in Human Fibroblasts Is Induced by Bovine Milk.

    PubMed

    Kippenberger, Stefan; Zöller, Nadja; Kleemann, Johannes; Müller, Jutta; Kaufmann, Roland; Hofmann, Matthias; Bernd, August; Meissner, Markus; Valesky, Eva

    2015-01-01

    Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids.

  16. Characterization of effector components from the humoral and cellular immune response stimulated by melanoma cells exhibiting modified IGF-1 expression.

    PubMed

    Zhu, Chaobin; Trabado, Séverine; Fan, Ye; Trojan, Jerzy; Lone, Yu-Chun; Giron-Michel, Julien; Duc, Huynh-Thien

    2015-03-01

    Modified melanoma B16 cells inhibited in their IGF-1 expression (B16MOD), on the contrary to the IGF-1 fully expressed parental wild-type (B16WT) counterpart, were shown to stimulate humoral as well as cellular immune responses. Among humoral components, the neutralizing and complement-fixing antibodies of IgM and essentially IgG2 (a+b) isotypes exhibited in vitro and in vivo effects upon tumour growth, while the IgG1 antibody isotype promoted enhanced tumour proliferation. As for the cellular immunity, it was found that the T CD8(+) lymphocyte subpopulation remained the main potent and long lasting immune active effector regulating tumour growth.

  17. The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1)

    PubMed Central

    Wolfe, Andrew; Divall, Sara; Wu, Sheng

    2014-01-01

    The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction. PMID:24929098

  18. A polymorphic repeat in the IGF1 promoter influences the risk of endometrial cancer

    PubMed Central

    Bolton, Katherine A; Avery-Kiejda, Kelly A; Holliday, Elizabeth G; Attia, John; Bowden, Nikola A

    2016-01-01

    Due to the lack of high-throughput genetic assays for tandem repeats, there is a paucity of knowledge about the role they may play in disease. A polymorphic CA repeat in the promoter region of the insulin-like growth factor 1 gene (IGF1 has been studied extensively over the past 10 years for association with the risk of developing breast cancer, among other cancers, with variable results. The aim of this study was to determine if this CA repeat is associated with the risk of developing breast cancer and endometrial cancer. Using a case–control design, we analysed the length of this CA repeat in a series of breast cancer and endometrial cancer cases and compared this with a control population. Our results showed an association when both alleles were considered in breast and endometrial cancers (P=0.029 and 0.011, respectively), but this did not pass our corrected threshold for significance due to multiple testing. When the allele lengths were analysed categorically against the most common allele length of 19 CA repeats, an association was observed with the risk of endometrial cancer due to a reduction in the number of long alleles (P=0.013). This was confirmed in an analysis of the long alleles separately for endometrial cancer risk (P=0.0012). Our study found no association between the length of this polymorphic CA repeat and breast cancer risk. The significant association observed between the CA repeat length and the risk of developing endometrial cancer has not been previously reported. PMID:27090263

  19. The mRNA expression of insulin-like growth factor-1 (Igf1) is decreased in the rat frontal cortex following gamma-hydroxybutyrate (GHB) administration.

    PubMed

    Brolin, Erika; Johansson, Jenny; Zelleroth, Sofia; Diwakarla, Shanti; Nyberg, Fred; Grönbladh, Alfhild; Hallberg, Mathias

    2017-02-26

    In recent years, growth hormone (GH), together with its secondary mediators insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-2 (IGF-2), have been highlighted for their beneficial effects in the central nervous system (CNS), in particular as cognitive enhancers. Cognitive processes, such as learning and memory, are known to be impaired in individuals suffering from substance abuse. In the present study, we investigated the effect of gamma-hydroxybuturate (GHB), an illicit drug used for its sedating and euphoric properties, on genes associated with the somatotrophic axis in regions of the brain important for cognitive function. Sprague Dawley rats (n=36) were divided into three groups and administered either saline, GHB 50mg/kg or GHB 300mg/kg orally for seven days. The levels of Ghr, Igf1 and Igf2 gene transcripts were analyzed using qPCR in brain regions involved in cognition and dependence. The levels of IGF-1 in blood plasma were also determined using ELISA. The results demonstrated a significant down-regulation of Igf1 mRNA expression in the frontal cortex in high-dose treated rats. Moreover, a significant correlation between Igf1 and Ghr mRNA expression was found in the hippocampus, the frontal cortex, and the caudate putamen, indicating local regulation of the GH/IGF-1 axis. To summarize, the current study concludes that chronic GHB treatment influences gene expression of Ghr and Igf1 in brain regions involved in cognitive function.

  20. Role of the GH-IGF-1 system in Atlantic salmon and rainbow trout postsmolts at elevated water temperature.

    PubMed

    Hevrøy, Ernst M; Tipsmark, Christian K; Remø, Sofie C; Hansen, Tom; Fukuda, Miki; Torgersen, Thomas; Vikeså, Vibeke; Olsvik, Pål A; Waagbø, Rune; Shimizu, Munetaka

    2015-10-01

    A comparative experiment with Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) postsmolts was conducted over 35 days to provide insight into how growth, respiration, energy metabolism and the growth hormone (GH) and insulin-like growth factor 1 (IGF-1) system are regulated at elevated sea temperatures. Rainbow trout grew better than Atlantic salmon, and did not show reduced growth at 19 °C. Rainbow trout kept at 19 °C had increased blood hemoglobin concentration compared to rainbow trout kept at 13 °C, while salmon did not show the same hemoglobin response due to increased temperature. Both species showed reduced length growth and decreased muscle glycogen stores at 19 °C. Circulating IGF-1 concentration was higher in rainbow trout than in Atlantic salmon, but was not affected by temperature in either species. Plasma IGF-binding protein 1b (IGFBP-1b) concentration was reduced in Atlantic salmon reared at 19 °C after 15 days but increased in rainbow trout at 19 °C after 35 days. The igfbp1b mRNA level in liver showed a positive correlation to plasma concentrations of glucose and IGFBP-1b, suggesting involvement of this binding protein in carbohydrate metabolism at 19 °C. At this temperature muscle igfbp1a mRNA was down-regulated in both species. The muscle expression of this binding protein correlated negatively with muscle igf1 and length growth. The plasma IGFBP-1b concentration and igfbp1b and igfbp1a expression suggests reduced muscle igf1 signaling at elevated temperature leading to glucose allostasis, and that time course is species specific due to higher thermal tolerance in rainbow trout.

  1. Novel polymorphisms of the IGF1R gene and their association with average daily gain in Egyptian buffalo (Bubalus bubalis).

    PubMed

    El-Magd, M A; Abbas, H E; El-kattawy, A M; Mokhbatly, A

    2013-08-01

    The objective of this study was to detect insulin-like growth factor 1 receptor (IGF1R) polymorphisms, their allele, and genotype frequencies and to determine associations between these polymorphisms and growth traits in Egyptian water buffalo. Three loci of the IGF1R coding region were amplified by RT-PCR and, subsequently, subjected to sequence analysis, followed by single-strand conformation polymorphism to identify different allelic patterns. A total of 11 novel polymorphisms were detected; 6 SNPs among Egyptian water buffaloes and 5 polymorphisms compared with Indian buffalo (Y12700). Three of those polymorphisms; GAG Indel polymorphism, C261G, and G263C SNPs, were nonsynonymous mutations. The GAG Indel polymorphism led to deletion of E (glutamic) amino acid (aa) in the IGF1R of Egyptian water buffaloes compared with Indian buffalo. However, C261G SNP, which replaced A (alanine) by G (glycine) aa, and G263C SNP, which changed A (alanine) to P (proline) aa, were detected among Egyptian water buffaloes. Three different single-strand conformation polymorphism patterns were observed in exon 21: CC/CC, GG/GG, and CG/GC with frequencies of 0.291, 0.253, and 0.556, respectively. The heterozygous animals (CG/GC) had a higher ADG than homozygous animals (CC/CC and GG/GG) from birth to 6 mo of age. We conclude that the heterozygous haplotype, C261G/G263C, in exon 21 of the IGF1R gene is associated with the ADG during the early stages of life (from birth to 6 mo of age) and could be used as a genetic marker for selection of growth traits in Egyptian buffalo.

  2. The influence of manganese deficiency on serum IGF-1 and IGF binding proteins in the male rat.

    PubMed

    Clegg, M S; Donovan, S M; Monaco, M H; Baly, D L; Ensunsa, J L; Keen, C L

    1998-10-01

    Young male rats subjected to a dietary manganese (Mn) deficiency respond to the deficiency by reducing their growth rate. The growth hormone (GH)/insulin-like growth factor (IGF) axis is critical for linear growth; this system is exquisitely sensitive to the nutritional state of the animal. In this study, we examined circulating GH, IGF-1, and insulin levels in Mn-deficient (-Mn; fed a 0.5 microg Mn/g diet) and sufficient (+Mn; fed a 45 microg Mn/g diet) male Sprague-Dawley rats. Additionally, we examined the distribution of circulating IGF binding proteins (IGFBPs) in animals of both dietary groups as these proteins modulate IGF-1 action in vivo and in vitro, and have been demonstrated to be altered in a number of nutritional and physiological states. Body weight was significantly reduced in -Mn relative to +Mn rats. Consistent with other studies, daily food intake was not altered. However, cumulative food intake (over 3 months) was marginally lower in -Mn versus +Mn animals. -Mn animals displayed lower circulating concentrations of IGF-1 (66% of control levels) and insulin (60% of control levels) despite having significant elevations in circulating GH levels relative to +Mn animals (140% of control levels). The IGFBP profile of -Mn animals reflected their elevated GH status, as we observed increased binding of tracer (125I-IGF-1) to the circulating IGFBP-3 complex (120% of control binding) using native chromatography techniques. Interestingly, the lower circulating insulin concentrations of -Mn animals did not result in dramatic elevations in lower-molecular-weight binding proteins. In summary, we demonstrate that in young male rats, Mn deficiency is associated with alterations in IGF metabolism. These alterations may contribute to the growth and bone abnormalities observed in -Mn animals.

  3. Prenatal ethanol exposure increases osteoarthritis susceptibility in female rat offspring by programming a low-functioning IGF-1 signaling pathway.

    PubMed

    Ni, Qubo; Tan, Yang; Zhang, Xianrong; Luo, Hanwen; Deng, Yu; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

    2015-10-05

    Epidemiological evidence indicates that osteoarthritis (OA) and prenatal ethanol exposure (PEE) are both associated with low birth weight but possible causal interrelationships have not been investigated. To investigate the effects of PEE on the susceptibility to OA in adult rats that experienced intrauterine growth retardation (IUGR), and to explore potential intrauterine mechanisms, we established the rat model of IUGR by PEE and dexamethasone, and the female fetus and 24-week-old adult offspring subjected to strenuous running for 6 weeks were sacrificed. Knee joints were collected from fetuses and adult offspring for histochemistry, immunohistochemistry and qPCR assays. Histological analyses and the Mankin score revealed increased cartilage destruction and accelerated OA progression in adult offspring from the PEE group compared to the control group. Immunohistochemistry showed reduced expression of insulin-like growth factor-1 (IGF-1) signaling pathway components. Furthermore, fetuses in the PEE group experienced IUGR but exhibited a higher postnatal growth rate. The expression of many IGF-1 signaling components was downregulated, which coincided with reduced amounts of type II collagen in the epiphyseal cartilage of fetuses in the PEE group. These results suggest that PEE enhances the susceptibility to OA in female adult rat offspring by down-regulating IGF-1 signaling and retarding articular cartilage development.

  4. Targeting colorectal cancer via its microenvironment by inhibiting IGF-1 Receptor-insulin receptor substrate and STAT3 signaling

    PubMed Central

    Sanchez-Lopez, Elsa; Flashner-Abramson, Efrat; Shalapour, Shabnam; Zhong, Zhenyu; Taniguchi, Koji; Levitzki, Alexander; Karin, Michael

    2015-01-01

    The tumor microenvironment (TME) exerts critical pro-tumorigenic effects through cytokines and growth factors that support cancer cell proliferation, survival, motility and invasion. Insulin-like growth factor-1 (IGF-1) and Signal transducer and activator of transcription 3 (STAT3) stimulate colorectal cancer (CRC) development and progression via cell autonomous and microenvironmental effects. Using a unique inhibitor, NT157, which targets both IGF-1 receptor (IGF-1R) and STAT3, we show that these pathways regulate many TME functions associated with sporadic colonic tumorigenesis in CPC-APC mice, in which cancer development is driven by loss of the Apc tumor suppressor gene. NT157 causes a substantial reduction in tumor burden by affecting cancer cells, cancer-associated fibroblasts (CAF) and myeloid cells. Decreased cancer cell proliferation and increased apoptosis were accompanied by inhibition of CAF activation and decreased inflammation. Furthermore, NT157 inhibited expression of pro-tumorigenic cytokines, chemokines and growth factors, including IL-6, IL-11 and IL-23 as well as CCL2, CCL5, CXCL7, CXCL5, ICAM1 and TGFβ; decreased cancer cell migratory activity and reduced their proliferation in the liver. NT157 represents a new class of anti-cancer drugs that affect both the malignant cell and its supportive microenvironment. PMID:26364612

  5. Effects of exercise and poor indoor air quality on learning, memory and blood IGF-1 in adolescent mice.

    PubMed

    Uysal, N; Kiray, M; Sisman, A R; Baykara, B; Aksu, I; Dayi, A; Gencoglu, C; Evren, M; Buyuk, E; Cetin, F; Acikgoz, O

    2014-02-01

    It is known that regular aerobic exercise enhances cognitive functions and increases blood insulin-like growth factor 1 (IGF-1) levels. People living in urban areas spend most of their time indoors and indoor air quality can affect health. We investigated the effects of aerobic exercise in poor and good air quality environments on hippocampus and prefrontal cortex (PFC) neurons, anxiety, and spatial learning and memory in adolescent mice. Poor air quality impaired spatial learning and memory; exercise did not affect learning or memory impairment. Exercise in a good air quality environment improved spatial learning and memory. Poor air quality increased apoptosis in the hippocampus and PFC. Both exercised and sedentary groups living in a poor air quality environment had lower serum IGF-1 levels than those living in a good air quality environment. Living in a poor air quality environment has negative effects on the hippocampus, PFC and blood IGF-1 levels in adolescent mice, but exercise did not alter the negative effects of poor air quality.

  6. Prenatal ethanol exposure increases osteoarthritis susceptibility in female rat offspring by programming a low-functioning IGF-1 signaling pathway

    NASA Astrophysics Data System (ADS)

    Ni, Qubo; Tan, Yang; Zhang, Xianrong; Luo, Hanwen; Deng, Yu; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

    2015-10-01

    Epidemiological evidence indicates that osteoarthritis (OA) and prenatal ethanol exposure (PEE) are both associated with low birth weight but possible causal interrelationships have not been investigated. To investigate the effects of PEE on the susceptibility to OA in adult rats that experienced intrauterine growth retardation (IUGR), and to explore potential intrauterine mechanisms, we established the rat model of IUGR by PEE and dexamethasone, and the female fetus and 24-week-old adult offspring subjected to strenuous running for 6 weeks were sacrificed. Knee joints were collected from fetuses and adult offspring for histochemistry, immunohistochemistry and qPCR assays. Histological analyses and the Mankin score revealed increased cartilage destruction and accelerated OA progression in adult offspring from the PEE group compared to the control group. Immunohistochemistry showed reduced expression of insulin-like growth factor-1 (IGF-1) signaling pathway components. Furthermore, fetuses in the PEE group experienced IUGR but exhibited a higher postnatal growth rate. The expression of many IGF-1 signaling components was downregulated, which coincided with reduced amounts of type II collagen in the epiphyseal cartilage of fetuses in the PEE group. These results suggest that PEE enhances the susceptibility to OA in female adult rat offspring by down-regulating IGF-1 signaling and retarding articular cartilage development.

  7. Prenatal ethanol exposure increases osteoarthritis susceptibility in female rat offspring by programming a low-functioning IGF-1 signaling pathway

    PubMed Central

    Ni, Qubo; Tan, Yang; Zhang, Xianrong; Luo, Hanwen; Deng, Yu; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

    2015-01-01

    Epidemiological evidence indicates that osteoarthritis (OA) and prenatal ethanol exposure (PEE) are both associated with low birth weight but possible causal interrelationships have not been investigated. To investigate the effects of PEE on the susceptibility to OA in adult rats that experienced intrauterine growth retardation (IUGR), and to explore potential intrauterine mechanisms, we established the rat model of IUGR by PEE and dexamethasone, and the female fetus and 24-week-old adult offspring subjected to strenuous running for 6 weeks were sacrificed. Knee joints were collected from fetuses and adult offspring for histochemistry, immunohistochemistry and qPCR assays. Histological analyses and the Mankin score revealed increased cartilage destruction and accelerated OA progression in adult offspring from the PEE group compared to the control group. Immunohistochemistry showed reduced expression of insulin-like growth factor-1 (IGF-1) signaling pathway components. Furthermore, fetuses in the PEE group experienced IUGR but exhibited a higher postnatal growth rate. The expression of many IGF-1 signaling components was downregulated, which coincided with reduced amounts of type II collagen in the epiphyseal cartilage of fetuses in the PEE group. These results suggest that PEE enhances the susceptibility to OA in female adult rat offspring by down-regulating IGF-1 signaling and retarding articular cartilage development. PMID:26434683

  8. The mechanism of transactivation regulation due to polymorphic short tandem repeats (STRs) using IGF1 promoter as a model

    PubMed Central

    Chen, Holly Y.; Ma, Suk Ling; Huang, Wei; Ji, Lindan; Leung, Vincent H. K.; Jiang, Honglin; Yao, Xiaoqiang; Tang, Nelson L. S.

    2016-01-01

    Functional short tandem repeats (STR) are polymorphic in the population, and the number of repeats regulates the expression of nearby genes (known as expression STR, eSTR). STR in IGF1 promoter has been extensively studied for its association with IGF1 concentration in blood and various clinical traits and represents an important eSTR. We previously used an in-vitro luciferase reporter model to examine the interaction between STRs and SNPs in IGF1 promoter. Here, we further explored the mechanism how the number of repeats of the STR regulates gene transcription. An inverse correlation between the number of repeats and the extent of transactivation was found in a haplotype consisting of three promoter SNPs (C-STR-T-T). We showed that these adjacent SNPs located outside the STR were required for the STR to function as eSTR. The C allele of rs35767 provides a binding site for CCAAT/enhancer-binding-protein δ (C/EBPD), which is essential for the gradational transactivation property of eSTR and FOXA3 may also be involved. Therefore, we propose a mechanism in which the gradational transactivation by the eSTR is caused by the interaction of one or more transcriptional complexes located outside the STR, rather than by direct binding to a repeat motif of the STR. PMID:27910883

  9. Endometrial Cancer Insulin-Like Growth Factor 1 Receptor (IGF1R) Expression Increases with Body Mass Index and Is Associated with Pathologic Extent and Prognosis

    PubMed Central

    Joehlin-Price, Amy S.; Stephens, Julie A.; Zhang, Jianying; Backes, Floor J.; Cohn, David E.; Suarez, Adrian A.

    2016-01-01

    Background Obesity is a main risk factor for endometrial carcinoma (EC). Insulin-like growth factor 1 receptor (IGF1R) expression may influence this association. Methods IGF1R IHC was performed on a tissue microarray with 894 EC and scored according to the percentage and intensity of staining to create immunoreactivity scores, which were dichotomized into low and high IGF1R expression groups. Logistic regression modeling assessed associations with body mass index (BMI), age, histology, pathologic extent of disease (pT), and lymph node metastasis (pN). Overall survival (OS) and disease-free survival (DFS) were compared between IGF1R expression groups using Kaplan–Meier curves and log-rank tests. Results The proportion of patients with high IGF1R expression increased as BMI (<30, 30–39, and 40+ kg/m2) increased (P = 0.002). The adjusted odds of having high IGF1R expression was 1.49 [95% confidence interval (CI), 1.05–2.10, P = 0.024] for patients with BMI 30 to 39 kg/m2 compared with <30 kg/m2 and 1.62 (95% CI, 1.13–2.33, P = 0.009) for patients with BMI 40+ kg/m2 compared with <30 kg/m2. High IGF1R expression was associated with pT and pN univariately and with pT after adjusting for BMI, pN, age, and histologic subtype. DFS and OS were better with high IGF1R expression, P = 0.020 and P = 0.002, respectively, but DFS was not significant after adjusting for pT, pN, and histologic subtype of the tumor. Conclusions There is an association between BMI and EC IGF1R expression. Higher IGF1R expression is associated with lower pT and better DFS and OS. Impact These findings suggest a link between IGF1R EC expression and obesity, as well as IGF1R expression and survival. PMID:26682991

  10. Metformin inhibits the proliferation of human prostate cancer PC-3 cells via the downregulation of insulin-like growth factor 1 receptor

    SciTech Connect

    Kato, Haruo Sekine, Yoshitaka; Furuya, Yosuke; Miyazawa, Yoshiyuki; Koike, Hidekazu; Suzuki, Kazuhiro

    2015-05-22

    Metformin is a biguanide drug that is widely used for the treatment of type 2 diabetes. Recent studies have shown that metformin inhibits cancer cell proliferation and tumor growth both in vitro and in vivo. The anti-tumor mechanisms of metformin include activation of the AMP-activated protein kinase/mTOR pathway and direct inhibition of insulin/insulin-like growth factor (IGF)-mediated cellular proliferation. However, the anti-tumor mechanism in prostate cancer remains unclear. Because activation of the IGF-1 receptor (IGF-1R) is required for prostate cell proliferation, IGF-1R inhibitors may be of therapeutic value. Accordingly, we examined the effects of metformin on IGF-1R signaling in prostate cancer cells. Metformin significantly inhibited PC-3 cell proliferation, migration, and invasion. IGF-1R mRNA expression decreased significantly after 48 h of treatment, and IGF-1R protein expression decreased in a similar manner. IGF-1R knockdown by siRNA transfection led to inhibited proliferation, migration and invasion of PC-3 cells. IGF-1 activated both ERK1/2 and Akt, but these effects were attenuated by metformin treatment. In addition, intraperitoneal treatment with metformin significantly reduced tumor growth and IGF-1R mRNA expression in PC-3 xenografts. Our results suggest that metformin is a potent inhibitor of the IGF-1/IGF-1R system and may be beneficial in prostate cancer treatment. - Highlights: • Metformin inhibited PC-3 cell proliferation, migration, and invasion. • Metformin decreased IGF-1R mRNA and protein expressions in PC-3 cells. • Metformin inhibited IGF-1 induced ERK and Akt phosphorylations in PC-3 cells. • Metformin treatment inhibited PC-3 cell growth and IGF-1R expression in vivo. • Metformin may be a potent inhibitor of the IGF-1/IGF-1R signaling.

  11. Diminished skeletal muscle microRNA expression with aging is associated with attenuated muscle plasticity and inhibition of IGF-1 signaling.

    PubMed

    Rivas, Donato A; Lessard, Sarah J; Rice, Nicholas P; Lustgarten, Michael S; So, Kawai; Goodyear, Laurie J; Parnell, Laurence D; Fielding, Roger A

    2014-09-01

    Older individuals have a reduced capacity to induce muscle hypertrophy with resistance exercise (RE), which may contribute to the age-induced loss of muscle mass and function, sarcopenia. We tested the novel hypothesis that dysregulation of microRNAs (miRNAs) may contribute to reduced muscle plasticity with aging. Skeletal muscle expression profiling of protein-coding genes and miRNA was performed in younger (YNG) and older (OLD) men after an acute bout of RE. 21 miRNAs were altered by RE in YNG men, while no RE-induced changes in miRNA expression were observed in OLD men. This striking absence in miRNA regulation in OLD men was associated with blunted transcription of mRNAs, with only 42 genes altered in OLD men vs. 175 in YNG men following RE, demonstrating a reduced adaptability of aging muscle to exercise. Integrated bioinformatics analysis identified miR-126 as an important regulator of the transcriptional response to exercise and reduced lean mass in OLD men. Manipulation of miR-126 levels in myocytes, in vitro, revealed its direct effects on the expression of regulators of skeletal muscle growth and activation of insulin growth factor 1 (IGF-1) signaling. This work identifies a mechanistic role of miRNA in the adaptation of muscle to anabolic stimulation and reveals a significant impairment in exercise-induced miRNA/mRNA regulation with aging.

  12. The flavones apigenin and luteolin induce FOXO1 translocation but inhibit gluconeogenic and lipogenic gene expression in human cells.

    PubMed

    Bumke-Vogt, Christiane; Osterhoff, Martin A; Borchert, Andrea; Guzman-Perez, Valentina; Sarem, Zeinab; Birkenfeld, Andreas L; Bähr, Volker; Pfeiffer, Andreas F H

    2014-01-01

    The flavones apigenin (4',5,7,-trihydroxyflavone) and luteolin (3',4',5,7,-tetrahydroxyflavone) are plant secondary metabolites with antioxidant, antiinflammatory, and anticancer activities. We evaluated their impact on cell signaling pathways related to insulin-resistance and type 2 diabetes. Apigenin and luteolin were identified in our U-2 OS (human osteosarcoma) cell screening assay for micronutrients triggering rapid intracellular translocation of the forkhead box transcription factor O1 (FOXO1), an important mediator of insulin signal transduction. Insulin reversed the translocation of FOXO1 as shown by live cell imaging. The impact on the expression of target genes was evaluated in HepG2 (human hepatoma) cells. The mRNA-expression of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pc), the lipogenic enzymes fatty-acid synthase (FASN) and acetyl-CoA-carboxylase (ACC) were down-regulated by both flavones with smaller effective dosages of apigenin than for luteolin. PKB/AKT-, PRAS40-, p70S6K-, and S6-phosphorylation was reduced by apigenin and luteolin but not that of the insulin-like growth factor receptor IGF-1R by apigenin indicating a direct inhibition of the PKB/AKT-signaling pathway distal to the IGF-1 receptor. N-acetyl-L-cysteine did not prevent FOXO1 nuclear translocation induced by apigenin and luteolin, suggesting that these flavones do not act via oxidative stress. The roles of FOXO1, FOXO3a, AKT, sirtuin1 (SIRT1), and nuclear factor (erythroid-derived2)-like2 (NRF2), investigated by siRNA knockdown, showed differential patterns of signal pathways involved and a role of NRF2 in the inhibition of gluconeogenic enzyme expression. We conclude that these flavones show an antidiabetic potential due to reduction of gluconeogenic and lipogenic capacity despite inhibition of the PKB/AKT pathway which justifies detailed investigation in vivo.

  13. Biodegradable Microcarriers of Poly(Lactide-co-Glycolide) and Nano-Hydroxyapatite Decorated with IGF-1 via Polydopamine Coating for Enhancing Cell Proliferation and Osteogenic Differentiation.

    PubMed

    Gao, Tianlin; Zhang, Ning; Wang, Zongliang; Wang, Yu; Liu, Ya; Ito, Yoshihiro; Zhang, Peibiao

    2015-08-01

    In this study, insulin-like growth factor 1 (IGF-1) was successfully immobilized on the poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HA) and pure PLGA microcarriers via polydopamine (pDA). The results demonstrated that the pDA layer facilitated simple and highly efficient immobilization of peptides on the microcarriers within 20 min. Mouse adipose-derived stem cells (ADSCs) attachment and proliferation on IGF-1-immobilized microcarriers were much higher than non-immobilized ones. More importantly, the IGF-1-immobilized PLGA/HA microcarriers significantly increased alkaline phosphatase (ALP) activity and expression of osteogenesis-related genes of ADSCs. Therefore, it is considered that the IGF-1-decorated PLGA/HA microcarriers will be of great value in the bone tissue engineering.

  14. Clinical features and natural course of acromegaly in patients with discordance in the nadir GH level on the oral glucose test and the IGF-1 value at 3 months after adenomectomy.

    PubMed

    Kinoshita, Yasuyuki; Tominaga, Atsushi; Usui, Satoshi; Arita, Kazunori; Sakoguchi, Tetsuhiko; Sugiyama, Kazuhiko; Kurisu, Kaoru

    2016-04-01

    Discordant GH and IGF-1 levels after adenomectomy are well recognized in acromegalics. The aim of this study was to evaluate the clinical features and natural course of postoperative acromegaly associated with discordant GH and IGF-1 levels over a postoperative period. A total of 69 acromegalics underwent surgery with at least 1 year of follow-up and received 75-g oral glucose tolerance tests (OGTTs) at 3 months postoperatively. The patients were categorized into four groups according to the postoperative nadir GH levels and IGF-1 levels: controlled group (normal GH and normal IGF-1), high-IGF-1 group (normal GH and high IGF-1), high-GH group (high GH and normal IGF-1), and uncontrolled group (high GH and high IGF-1). The incidence of discordant GH and IGF-1 levels was 27.5%: high-IGF-1 group = 10.1% (n = 7) and high-GH group = 17.4% (n = 12). All patients in the high-IGF-1 group exhibited a decline in the IGF-1 level after surgery, with normalization observed in 71.4% of the patients without additional treatment (median 23 months). These subjects had preoperatively high IGF-1 levels despite not demonstrating higher GH levels than the patients in the controlled group. On the other hand, four patients in the high-GH group exhibited an elevated nadir GH level higher than 1.0 μg/L on repeated OGTTs after 3 months, and one patient experienced a recurrence of acromegaly. Patients in the high-IGF-1 group require no additional treatments, and their IGF-1 levels are likely to normalize within a few years. However, patients in the high-GH group should be carefully followed due to the possibility of recurrence.

  15. Epithelial-mesenchymal transition predicts sensitivity to the dual IGF-1R/IR inhibitor OSI-906 in hepatocellular carcinoma cell lines.

    PubMed

    Zhao, Hui; Desai, Vidhi; Wang, Jian; Epstein, David M; Miglarese, Mark; Buck, Elizabeth

    2012-02-01

    A growing body of data indicates that inhibiting the type 1 insulin-like growth factor receptor (IGF-1R) might be an effective treatment strategy for hepatocellular carcinoma (HCC). OSI-906 is a dual IGF-1R/IR kinase inhibitor currently in phase II clinical development for HCC. However, biomarkers are lacking to help identify patients with HCC who are more likely to benefit from OSI-906 treatment. We sought to determine the effect of OSI-906 on proliferation against a panel of 21 HCC cell lines and to investigate molecular determinants of responsiveness to OSI-906. We identified a subset of HCC cell lines that was sensitive to OSI-906, and sensitivity is associated with elevated phosphorylation levels of IGF-1R and IR and greater inhibition of AKT signaling. Dual targeting of both receptors seems to be important for maximal inhibition as treatment with a selective IGF-1R-neutralizing antibody was associated with increased IR signaling, whereas OSI-906 fully inhibited both phosphorylated IR and IGF-1R and resulted in greater inhibition of the IRS/AKT pathway. Epithelial-mesenchymal transition (EMT) seems to predict HCC cell sensitivity to OSI-906, as the epithelial phenotype is strongly associated with expression of IGF-2 and IR, activation of IGF-1R and IR, and sensitivity to OSI-906, alone or in combination with erlotinib. Induction of EMT upon treatment with TGFβ reduced sensitivity to OSI-906. Collectively, these data support the concept for dual IGF-1R/IR targeting in HCC, where EMT status and expressions of IGF-2 and IR may be used to identify those patients who are most likely to benefit from treatment with an IGF-1R/IR dual inhibitor.

  16. The Beneficial Impact of Antidepressant Drugs on Prenatal Stress-Evoked Malfunction of the Insulin-Like Growth Factor-1 (IGF-1) Protein Family in the Olfactory Bulbs of Adult Rats.

    PubMed

    Trojan, Ewa; Głombik, Katarzyna; Ślusarczyk, Joanna; Budziszewska, Bogusława; Kubera, Marta; Roman, Adam; Lasoń, Władysław; Basta-Kaim, Agnieszka

    2016-02-01

    Insulin-like growth factor-1 (IGF-1) promotes the growth, differentiation, and survival of both neurons and glial cells, and it is believed to exert antidepressant-like ac