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Sample records for igf-1 induced human

  1. Human IGF1 pro-forms induce breast cancer cell proliferation via the IGF1 receptor.

    PubMed

    De Santi, Mauro; Annibalini, Giosuè; Barbieri, Elena; Villarini, Anna; Vallorani, Luciana; Contarelli, Serena; Berrino, Franco; Stocchi, Vilberto; Brandi, Giorgio

    2016-04-01

    IGF1 is a key regulator of tissue growth and development and has been implicated in the initiation and progression of various cancers, including breast cancer. Through IGF1 mRNA splicing different precursor pro-peptides, i.e., the IGF1Ea, IGF1Eb and IGF1Ec pro-forms, are formed whose biological roles in the pathogenesis of breast cancer have not been established yet. The objective of this study was to assess the biological activity of the IGF1 pro-forms in human breast cancer-derived cells. The different IGF1 pro-forms were generated through transient transfection of HEK293 cells with the respective vector constructs. The resulting conditioned media were applied in vitro to MCF7, T47D and ZR751 breast cancer-derived cell cultures. The recombinant human IGF1 pro-forms were also tested for their binding affinity to an anti-IGF1 specific antibody by immunoprecipitation. To determine whether the IGF1 pro-forms induce cell proliferation, mature IGF1 was neutralised in HEK293-derived conditioned media. We found that the IGF1 pro-forms were the only forms that were produced intra-cellularly, whereas both mature IGF1 and the IGF1 pro-forms were detected extra-cellularly. We also found that E peptides can impair the IGF1 pro-form binding affinity for the anti-IGF1 antibody and, thus, hamper an accurate measurement of the IGF1 pro-forms. Additionally, we found that the IGF1 antibody can completely inhibit IGF1-induced breast cancer cell proliferation and IGF1 receptor (IGF1R) phosphorylation, wheras the same antibody was found to only partially inhibit the biological activity of the pro-forms. Moreover, we found that the IGF1 pro-form activities can completely be inhibited by neutralising the IGF1R. Finally, we compared the bioactivity of the IGF1 pro-forms to that of mature IGF1, and found that the IGF1 pro-forms were less capable of phosphorylating the IGF1R in the breast cancer-derived cells tested. Our data indicate that IGF1 pro-forms can induce breast cancer cell

  2. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways.

    PubMed

    Vanamala, Jairam; Reddivari, Lavanya; Radhakrishnan, Sridhar; Tarver, Chris

    2010-05-26

    Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene), a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity) and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Resveratrol (100-150 microM) exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G0/G1-S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and activation of p53, suggesting its potential role as a

  3. 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.

  4. IGF-1R inhibition induces schedule-dependent sensitization of human melanoma to temozolomide.

    PubMed

    Ramcharan, Roger; Aleksic, Tamara; Kamdoum, Wilfride Petnga; Gao, Shan; Pfister, Sophia X; Tanner, Jordan; Bridges, Esther; Asher, Ruth; Watson, Amanda J; Margison, Geoffrey P; Woodcock, Mick; Repapi, Emmanouela; Li, Ji-Liang; Middleton, Mark R; Macaulay, Valentine M

    2015-11-24

    Prior studies implicate type 1 IGF receptor (IGF-1R) in mediating chemo-resistance. Here, we investigated whether IGF-1R influences response to temozolomide (TMZ), which generates DNA adducts that are removed by O6-methylguanine-DNA methyltransferase (MGMT), or persist causing replication-associated double-strand breaks (DSBs). Initial assessment in 10 melanoma cell lines revealed that TMZ resistance correlated with MGMT expression (r = 0.79, p = 0.009), and in MGMT-proficient cell lines, with phospho-IGF-1R (r = 0.81, p = 0.038), suggesting that TMZ resistance associates with IGF-1R activation. Next, effects of IGF-1R inhibitors (IGF-1Ri) AZ3801 and linsitinib (OSI-906) were tested on TMZ-sensitivity, cell cycle progression and DSB induction. IGF-1Ri sensitized BRAF wild-type and mutant melanoma cells to TMZ in vitro, an effect that was independent of MGMT. Cells harboring wild-type p53 were more sensitive to IGF-1Ri, and showed schedule-dependent chemo-sensitization that was most effective when IGF-1Ri followed TMZ. This sequence sensitized to clinically-achievable TMZ concentrations and enhanced TMZ-induced apoptosis. Simultaneous or prior IGF-1Ri caused less effective chemo-sensitization, associated with increased G1 population and reduced accumulation of TMZ-induced DSBs. Clinically relevant sequential (TMZ → IGF-1Ri) treatment was tested in mice bearing A375M (V600E BRAF, wild-type p53) melanoma xenografts, achieving peak plasma/tumor IGF-1Ri levels comparable to clinical Cmax, and inducing extensive intratumoral apoptosis. TMZ or IGF-1Ri caused minor inhibition of tumor growth (gradient reduction 13%, 25% respectively), while combination treatment caused supra-additive growth delay (72%) that was significantly different from control (p < 0.01), TMZ (p < 0.01) and IGF-1Ri (p < 0.05) groups. These data highlight the importance of scheduling when combining IGF-1Ri and other targeted agents with drugs that induce replication-associated DNA damage.

  5. Expression and regulation of INTELECTIN1 in human granulosa-lutein cells: role in IGF-1-induced steroidogenesis through NAMPT.

    PubMed

    Cloix, Lucie; Reverchon, Maxime; Cornuau, Marion; Froment, Pascal; Ramé, Christelle; Costa, Caroline; Froment, Gisèle; Lecomte, Pierre; Chen, Wenyong; Royère, Dominique; Guerif, Fabrice; Dupont, Joëlle

    2014-08-01

    INTELECTIN (ITLN) is an adipokine involved in the regulation of insulin sensitivity and inflammatory and immunity responses. Serum ITLN levels are lower in obese, diabetic, and polycystic ovary syndrome (PCOS) women than in control subjects. ITLN has never been studied in ovarian cells. Here, we identified ITLN1 in human ovarian follicles and investigated the molecular mechanisms involved in the regulation of its expression in response to the insulin sensitizers metformin and rosiglitazone, in human granulosa-lutein cells (hGLCs) and in a human ovarian granulosa-like tumor cell line (KGN). We also studied the effects of human recombinant ITLN1 (hRom1) on steroid production and on the activation of various signaling pathways. Using RT-PCR, immunoblotting, and immunohistochemistry, we found that INTL1 is present in human follicular cells. Using ELISA, we showed that INTL levels are similar in plasma and follicular fluid (FF) in control patients, whereas they are higher in FF than in plasma in PCOS patients. In KGN cells and hGLCs, insulin (10(-8) M), insulin-like growth factor-1 (IGF-1; 10(-8) M), and metformin (10(-2) M or 10(-3) M) increased INTL1 expression (mRNA and protein) after 12 and 24 h of stimulation. For metformin, this effect was mediated by adenosine monophosphate-activated kinase (PRKA). Furthermore, hRom1 increased nicotinamide phosphoribosyltransferase (NAMPT) expression in KGN and hGLCs. We also showed that hRom1 increased IGF-1-induced progesterone and estradiol secretion and this was associated with an increase in the STAR and CYP19A1 protein levels and an increase in IGF-1R signaling. Furthermore, all these data were abolished when NAMPT was knocked down in KGN cells, suggesting that INTL1 improves IGF-1-induced steroidogenesis through induction of NAMPT in hGLCs. © 2014 by the Society for the Study of Reproduction, Inc.

  6. Insulin-like growth factor-1 (IGF-1) enhances recovery from HgCl2-induced acute renal failure: the effects on renal IGF-1, IGF-1 receptor, and IGF-binding protein-1 mRNA.

    PubMed

    Friedlaender, M; Popovtzer, M M; Weiss, O; Nefesh, I; Kopolovic, J; Raz, I

    1995-04-01

    Several growth factors have been found to play an important role in the recovery from acute renal failure (ARF). The effect of the continuous subcutaneous infusion of human recombinant insulin-like growth factor (IGF)-1 (125 micrograms daily by osmotic minipumps) in a rat model of mercuric chloride (HgCl2)-induced ARF was examined. HgCl2 (4 mg/kg) induced ARF with a mortality that was unaffected by IGF-1. However, IGF-1 significantly enhanced functional and histologic recovery in the survivors, as measured by serum creatinine and creatinine clearance and by histologic scoring. Solution hybridization RNAase protection assays showed that renal IGF-1 mRNA, IGF-1 receptor (IGF-1R) mRNA, and IGF-binding protein-1 (IGFBP-1) mRNA were unaffected by exogenous IGF-1, but this treatment significantly increased renal IGF-1 in ARF rats compared with normal rats and ARF rats not receiving IGF-1. After ARF renal mRNA for IGF-1 was decreased, IGF-1R was unchanged and IGFBP-1 was increased. Similar changes occurred in IGF-1-infused ARF rats. Thus, (1) IGF-1 enhances recovery from nephrotoxic ARF both functionally and histologically; (2) in nephrotoxic ARF, there is (a) a reduction in IGF-1 mRNA expression that is not prevented by IGF-1 infusion, and (b) an increase in renal IGFBP-1 mRNA. This may allow a significant increase in renal IGF-1 levels in IGF-1-infused ARF rats, despite the decrease in renal IGF-1 mRNA. A local increase in renal IGFBP-1 and IGF-1 may explain the accelerated recovery from ATN in this model. It was concluded that HgCl2-induced ARF is amenable to improvement by IGF-1 infusion and that the increase in renal IGFBP-1 mRNA may be an important modulator in the recovery of the kidney.

  7. 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.

  8. 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.

  9. Identification of the IGF-1 processing product human Ec/rodent Eb peptide in various tissues: Evidence for its differential regulation after exercise-induced muscle damage in humans.

    PubMed

    Vassilakos, George; Philippou, Anastassios; Koutsilieris, Michael

    2017-02-01

    Insulin-like growth factor-1 (IGF-1) is a pleiotropic factor expressed in various tissues and plays a critical role in skeletal muscle physiology. Alternative splicing of the IGF-1 gene gives rise to different precursor polypeptides (isoforms) which could undergo post-translational cleavage, generating the common mature IGF-1 peptide and different carboxyl terminal extension (E-) peptides, with the fate of the latter being, so far, unknown. The objective if this study was to identify the IGF-1Ec forms or processing product(s), other than mature IGF-1, generated in different human and rodent tissues and particularly in human skeletal muscle after exercise-induced damage. Protein lysates from a wide range of human and rodent tissues were immunoblotted with a rabbit anti-human Ec polyclonal antibody raised against the last 24 amino acids of the C-terminal of the Ec peptide. This antibody can recognize the Ec peptide, both as part of IGF-1Ec and alone, and also the corresponding rodent forms, due to the high homology that the human Ec shares with the rodent Eb. We were able to confirm, for the first time, that the human Ec peptide and its rodent homologous Eb peptide are produced simultaneously with their precursor protein (pro-IGF-1Ec/Eb) in vivo, in a wide range of tissues (e.g. muscle, liver, heart). Proprotein convertase furin digestion of human muscle and liver protein lysates confirmed that the higher molecular form, pro-IGF-1Ec, can be cleaved to produce the free Ec peptide. Furthermore, initial evidence is provided that Ec peptide is differentially regulated during the process of muscle regeneration after exercise-induced damage in humans. The findings of this study possibly imply that the post-translational modification of the IGF-1Ec pro-peptide may regulate the bioavailability and activity of the processing product(s). Copyright © 2016. Published by Elsevier Ltd.

  10. 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.

  11. 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

  12. Insulin-like growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) expression in human lung in RDS and BPD.

    PubMed

    Chetty, Anne; Andersson, Sture; Lassus, Patrik; Nielsen, Heber C

    2004-02-01

    We hypothesize that IGF-1 and IGF-1R proteins are upregulated in lung epithelia and fibroblasts in RDS compared to normal development, and are further upregulated in BPD. We used immunohistochemistry to evaluate IGF-1 and IGF-R expression in lungs from autopsies of human stillbirths and RDS and BPD patients. IGF-1 and IGF-R immunostaining were present in fetal, RDS, and BPD lungs. In RDS, IGF-1 was present in alveolar epithelium and prominent in columnar and cuboidal airway epithelia. In BPD lungs, immunostaining was intensely increased in both airway and alveolar epithelia and in mesenchyme. The immunostaining index in bronchial epithelial cells and peribronchial myofibroblasts was significantly higher in BPD compared to RDS. IGF-1R expression was minimal in fetal lung and found mainly in mesenchyme. IGF-1R was increased in mesenchyme in RDS. In BPD it was especially increased in peribronchial and perialveolar mesenchyme. Immunostaining index for IGF-1R in epithelial cells and peribronchial myofibroblasts was increased in BPD compared to RDS. IGF-1 and IGF-R expression is low during fetal development, but is acutely upregulated in RDS, and persists with further upregulation in BPD. Copyright 2004 Wiley-Liss, Inc.

  13. Recombinant human IGF-1 produced by transgenic plant cell suspension culture enhances new bone formation in calvarial defects.

    PubMed

    Poudel, Sher Bahadur; Bhattarai, Govinda; Kook, Sung-Ho; Shin, Yun-Ji; Kwon, Tae-Ho; Lee, Seung-Youp; Lee, Jeong-Chae

    2017-07-30

    Transgenic plant cell suspension culture systems have been utilized extensively as convenient and efficient expression systems for the production of recombinant human growth factors. We produced insulin-like growth factor-1 using a plant suspension culture system (p-IGF-1) and explored its effect on new bone formation in calvarial defects. We also compared the bone regenerating potential of p-IGF-1 with commercial IGF-1 derived from Escherichia coli (e-IGF-1). Male C57BL/6 mice underwent calvarial defect surgery, and the defects were loaded with absorbable collagen sponge (ACS) only (ACS group) or ACS impregnated with 13μg of p-IGF-1 (p-IGF-1 group) or e-IGF-1 (e-IGF-1 group). The sham group did not receive any treatment with ACS or IGFs after surgery. Live μCT and histological analyses showed critical-sized bone defects in the sham group, whereas greater bone formation was observed in the p-IGF-1 and e-IGF-1 groups than the ACS group both 5 and 10weeks after surgery. Bone mineral density, bone volume, and bone surface values were also higher in the IGF groups than in the ACS group. Local delivery of p-IGF-1 or e-IGF-1 more greatly enhanced the expression of osteoblast-specific markers, but inhibited osteoclast formation, in newly formed bone compared with ACS control group. Specifically, p-IGF-1 treatment induced higher expression of alkaline phosphatase, osteocalcin, and osteopontin in the defect site than did e-IGF-1. Furthermore, treatment with p-IGF-1, but not e-IGF-1, increased mineralization of MC3T3-E1 cells, with the attendant upregulation of osteogenic marker genes. Collectively, our findings suggest the potential of p-IGF-1 in promoting the processes required for bone regeneration. Copyright © 2017. Published by Elsevier Ltd.

  14. PTK6 Regulates IGF-1-Induced Anchorage-Independent Survival

    PubMed Central

    Irie, Hanna Y.; Shrestha, Yashaswi; Selfors, Laura M.; Frye, Fabianne; Iida, Naoko; Wang, Zhigang; Zou, Lihua; Yao, Jun; Lu, Yiling; Epstein, Charles B.; Natesan, Sridaran; Richardson, Andrea L.; Polyak, Kornelia; Mills, Gordon B.; Hahn, William C.; Brugge, Joan S.

    2010-01-01

    Background Proteins that are required for anchorage-independent survival of tumor cells represent attractive targets for therapeutic intervention since this property is believed to be critical for survival of tumor cells displaced from their natural niches. Anchorage-independent survival is induced by growth factor receptor hyperactivation in many cell types. We aimed to identify molecules that critically regulate IGF-1-induced anchorage-independent survival. Methods and Results We conducted a high-throughput siRNA screen and identified PTK6 as a critical component of IGF-1 receptor (IGF-1R)-induced anchorage-independent survival of mammary epithelial cells. PTK6 downregulation induces apoptosis of breast and ovarian cancer cells deprived of matrix attachment, whereas its overexpression enhances survival. Reverse-phase protein arrays and subsequent analyses revealed that PTK6 forms a complex with IGF-1R and the adaptor protein IRS-1, and modulates anchorage-independent survival by regulating IGF-1R expression and phosphorylation. PTK6 is highly expressed not only in the previously reported Her2+ breast cancer subtype, but also in high grade ER+, Luminal B tumors and high expression is associated with adverse outcomes. Conclusions These findings highlight PTK6 as a critical regulator of anchorage-independent survival of breast and ovarian tumor cells via modulation of IGF-1 receptor signaling, thus supporting PTK6 as a potential therapeutic target for multiple tumor types. The combined genomic and proteomic approaches in this report provide an effective strategy for identifying oncogenes and their mechanism of action. PMID:20668531

  15. Adenoviral Mediated Gene Transfer of IGF-1 Enhances Wound Healing and Induces Angiogenesis

    PubMed Central

    Balaji, S.; LeSaint, M.; Bhattacharya, S. S.; Moles, C.; Dhamija, Y.; Kidd, M.; Le, L.D.; King, A.; Shaaban, A.; Crombleholme, T. M.; Bollyky, P.; Keswani, S. G.

    2014-01-01

    Background Chronic wounds are characterized by a wound healing and neovascularization deficit. Strategies to increase neovascularization can significantly improve chronic wound healing. Insulin like growth factor (IGF-1) is reported to be a keratinocyte mitogen and is believed to induce angiogenesis via a vascular endothelial growth factor (VEGF) dependent pathway. Using a novel ex vivo human dermal wound model and a diabetic impaired wound healing murine model, we hypothesized that adenoviral over expression of IGF-1 (Ad-IGF-1) will enhance wound healing and induce angiogenesis through a VEGF dependent pathway. Methods Ex vivo: 6 mm full thickness punch biopsies were obtained from normal human skin, and 3 mm full thickness wounds were created at the center. Skin explants were maintained at air liquid interface. Db/db murine model: 8 mm full thickness dorsal wounds in diabetic (db/db) mice were created. Treatment groups in both human ex vivo and in vivo db/db wound models include 1×108 PFU of Ad-IGF-1 or Ad-LacZ, and PBS (n=4–5/group). Cytotoxicity (LDH) was quantified at days 3, 5 and 7 for the human ex vivo wound model. Epithelial gap closure (H&E; Trichrome), VEGF expression (ELISA) and capillary density (CD 31+ CAPS/HPF) were analyzed at day 7. Results In the human ex vivo organ culture, the adenoviral vectors did not demonstrate any significant difference in cytotoxicity compared to PBS. Ad-IGF-1 over expression significantly increases basal keratinocyte migration, with no significant effect on epithelial gap closure. There was a significant increase in capillary density in the Ad-IGF-1 wounds. However, there was no effect on VEGF levels in Ad-IGF-1 samples compared to controls. In db/db wounds, Ad-IGF-1 over expression significantly improves epithelial gap closure and granulation tissue with a dense cellular infiltrate compared to controls. Ad-IGF-1 also increases capillary density, again with no significant difference in VEGF levels in the wounds compared

  16. 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

  17. Human IGF1 Regulates Midgut Oxidative Stress and Epithelial Homeostasis to Balance Lifespan and Plasmodium falciparum resistance in Anopheles stephensi

    PubMed Central

    Drexler, Anna L.; Pietri, Jose E.; Pakpour, Nazzy; Hauck, Eric; Wang, Bo; Glennon, Elizabeth K. K.; Georgis, Martha; Riehle, Michael A.; Luckhart, Shirley

    2014-01-01

    Insulin and insulin-like growth factor signaling (IIS) regulates cell death, repair, autophagy, and renewal in response to stress, damage, and pathogen challenge. Therefore, IIS is fundamental to lifespan and disease resistance. Previously, we showed that insulin-like growth factor 1 (IGF1) within a physiologically relevant range (0.013–0.13 µM) in human blood reduced development of the human parasite Plasmodium falciparum in the Indian malaria mosquito Anopheles stephensi. Low IGF1 (0.013 µM) induced FOXO and p70S6K activation in the midgut and extended mosquito lifespan, whereas high IGF1 (0.13 µM) did not. In this study the physiological effects of low and high IGF1 were examined in detail to infer mechanisms for their dichotomous effects on mosquito resistance and lifespan. Following ingestion, low IGF1 induced phosphorylation of midgut c-Jun-N-terminal kinase (JNK), a critical regulator of epithelial homeostasis, but high IGF1 did not. Low and high IGF1 induced midgut mitochondrial reactive oxygen species (ROS) synthesis and nitric oxide (NO) synthase gene expression, responses which were necessary and sufficient to mediate IGF1 inhibition of P. falciparum development. However, increased ROS and apoptosis-associated caspase-3 activity returned to baseline levels following low IGF1 treatment, but were sustained with high IGF1 treatment and accompanied by aberrant expression of biomarkers for mitophagy, stem cell division and proliferation. Low IGF1-induced ROS are likely moderated by JNK-induced epithelial cytoprotection as well as p70S6K-mediated growth and inhibition of apoptosis over the lifetime of A. stephensi to facilitate midgut homeostasis and enhanced survivorship. Hence, mitochondrial integrity and homeostasis in the midgut, a key signaling center for IIS, can be targeted to coordinately optimize mosquito fitness and anti-pathogen resistance for improved control strategies for malaria and other vector-borne diseases. PMID:24968248

  18. Selective disruption of insulin-like growth factor-1 (IGF-1) signaling via phosphoinositide-dependent kinase-1 prevents the protective effect of IGF-1 on human cancer cell death.

    PubMed

    Alberobello, A Teresa; D'Esposito, Vittoria; Marasco, Daniela; Doti, Nunzianna; Ruvo, Menotti; Bianco, Roberto; Tortora, Giampaolo; Esposito, Iolanda; Fiory, Francesca; Miele, Claudia; Beguinot, Francesco; Formisano, Pietro

    2010-02-26

    Insulin-like growth factor-1 (IGF-1) signaling system exerts a broad antiapoptotic function and plays a crucial role in resistance to anticancer therapies. Exposure of MCF-7 breast cancer cells to IGF-1 rapidly and transiently induced tyrosine phosphorylation and activation of phosphoinositide-dependent kinase-1 (PDK1). This was paralleled by Akt/protein kinase B and protein kinase C-zeta phosphorylation, at Thr(308) and Thr(410), respectively. IGF-1 treatment also enhanced PDK1 interaction with IGF-1 receptor (IGF-1R) in intact MCF-7 cells. Pulldown assays revealed that PDK1 bound IGF-1R in vitro and that the region encompassing amino acids 51-359 of PDK1 was necessary for the interaction. Synthetic peptides corresponding to IGF-1R C terminus amino acids 1295-1337 (C43) and to PDK1 amino acids 114-141 reduced in vitro IGF-1R/PDK1 interaction in a concentration-dependent manner. Loading of fluoresceinated-C43 (fluorescein isothiocyanate (FITC)-C43) into MCF-7 cells significantly reduced IGF-1R/PDK1 interaction and phosphorylation of PDK1 substrates. Moreover, FITC-C43 intracellular loading reverted the protective effect of IGF-1 on growth factor deprivation-induced cell death. Finally, the inhibition of IGF-1R/PDK1 interaction and signaling by FITC-C43 was accompanied by 2-fold enhanced killing capacity of cetuximab in human GEO colon adenocarcinoma cells and was sufficient to restore cell death in cetuximab-resistant cell clones. Thus, disruption of PDK1 interaction with IGF-1R reduces IGF-1 survival effects in cancer cells and may enhance cell death by anticancer agents.

  19. Selective Disruption of Insulin-like Growth Factor-1 (IGF-1) Signaling via Phosphoinositide-dependent Kinase-1 Prevents the Protective Effect of IGF-1 on Human Cancer Cell Death*

    PubMed Central

    Alberobello, A. Teresa; D'Esposito, Vittoria; Marasco, Daniela; Doti, Nunzianna; Ruvo, Menotti; Bianco, Roberto; Tortora, Giampaolo; Esposito, Iolanda; Fiory, Francesca; Miele, Claudia; Beguinot, Francesco; Formisano, Pietro

    2010-01-01

    Insulin-like growth factor-1 (IGF-1) signaling system exerts a broad antiapoptotic function and plays a crucial role in resistance to anticancer therapies. Exposure of MCF-7 breast cancer cells to IGF-1 rapidly and transiently induced tyrosine phosphorylation and activation of phosphoinositide-dependent kinase-1 (PDK1). This was paralleled by Akt/protein kinase B and protein kinase C-ζ phosphorylation, at Thr308 and Thr410, respectively. IGF-1 treatment also enhanced PDK1 interaction with IGF-1 receptor (IGF-1R) in intact MCF-7 cells. Pulldown assays revealed that PDK1 bound IGF-1R in vitro and that the region encompassing amino acids 51–359 of PDK1 was necessary for the interaction. Synthetic peptides corresponding to IGF-1R C terminus amino acids 1295–1337 (C43) and to PDK1 amino acids 114–141 reduced in vitro IGF-1R/PDK1 interaction in a concentration-dependent manner. Loading of fluoresceinated-C43 (fluorescein isothiocyanate (FITC)-C43) into MCF-7 cells significantly reduced IGF-1R/PDK1 interaction and phosphorylation of PDK1 substrates. Moreover, FITC-C43 intracellular loading reverted the protective effect of IGF-1 on growth factor deprivation-induced cell death. Finally, the inhibition of IGF-1R/PDK1 interaction and signaling by FITC-C43 was accompanied by 2-fold enhanced killing capacity of cetuximab in human GEO colon adenocarcinoma cells and was sufficient to restore cell death in cetuximab-resistant cell clones. Thus, disruption of PDK1 interaction with IGF-1R reduces IGF-1 survival effects in cancer cells and may enhance cell death by anticancer agents. PMID:20044479

  20. Ganglioside GM3 Mediates Glucose-Induced Suppression of IGF-1 Receptor-Rac1 Activation to Inhibit Keratinocyte Motility.

    PubMed

    Dam, Duncan Hieu M; Wang, Xiao-Qi; Sheu, Sarah; Vijay, Mahima; Shipp, Desmond; Miller, Luke; Paller, Amy S

    2017-02-01

    Activation of insulin-like growth factor-1 (IGF-1) receptor (IGF1R) signaling induces keratinocyte migration, but little is known about its regulation, including in diabetic wounds. GM3, a lipid raft ganglioside synthesized by GM3 synthase (GM3S), regulates receptor signaling. In diabetic mice, knockout or topically applied nanoconstruct-mediated knockdown of GM3S promotes wound edge IGF1R phosphorylation and re-epithelialization. Through modulating GM3 expression, we explored the role of GM3 in regulating human keratinocyte IGF1R signaling. Increases in GM3 and GM3S expression, including by exposure to high glucose, inhibit keratinocyte migration and IGF-1-induced chemotaxis in association with inhibition of IGF1R phosphorylation, suppression of Rac1 signaling, and activation of RhoA signaling. In contrast, GM3 depletion accelerates cell migration; increases cell velocity, displacement, and persistence; and activates IGF1R-Rac1 signaling. These data implicate GM3 in mediating glucose-induced suppression of IGF1R-Rac1 signaling. Furthermore, our findings provide evidence of a pivotal role for GM3-induced insulin resistance in impairing keratinocyte migration and reinforce the previously published studies in diabetic mice supporting GM3-depleting strategies as an approach for accelerating the healing of human diabetic wounds. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. 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

  2. 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.

  3. IGF-1 prevents simvastatin-induced myotoxicity in C2C12 myotubes.

    PubMed

    Bonifacio, Annalisa; Sanvee, Gerda M; Brecht, Karin; Kratschmar, Denise V; Odermatt, Alex; Bouitbir, Jamal; Krähenbühl, Stephan

    2017-05-01

    Statins are generally well tolerated, but treatment with these drugs may be associated with myopathy. The mechanisms of statin-associated myopathy are not completely understood. Statins inhibit AKT phosphorylation by an unclear mechanism, whereas insulin-like growth factor (IGF-1) activates the IGF-1/AKT signaling pathway and promotes muscle growth. The aims of the study were to investigate mechanisms of impaired AKT phosphorylation by simvastatin and to assess effects of IGF-1 on simvastatin-induced myotoxicity in C2C12 myotubes. C2C12 mouse myotubes were exposed to 10 μM simvastatin and/or 10 ng/mL IGF-1 for 18 h. Simvastatin inhibited the IGF-1/AKT signaling pathway, resulting in increased breakdown of myofibrillar proteins, impaired protein synthesis and increased apoptosis. Simvastatin inhibited AKT S473 phosphorylation, indicating reduced activity of mTORC2. In addition, simvastatin impaired stimulation of AKT T308 phosphorylation by IGF-1, indicating reduced activation of the IGF-1R/PI3K pathway by IGF-1. Nevertheless, simvastatin-induced myotoxicity could be at least partially prevented by IGF-1. The protective effects of IGF-1 were mediated by activation of the IGF-1R/AKT signaling cascade. Treatment with IGF-1 also suppressed muscle atrophy markers, restored protein synthesis and inhibited apoptosis. These results were confirmed by normalization of myotube morphology and protein content of C2C12 cells exposed to simvastatin and treated with IGF-1. In conclusion, impaired activity of AKT can be explained by reduced function of mTORC2 and of the IGF-1R/PI3K pathway. IGF-1 can prevent simvastatin-associated cytotoxicity and metabolic effects on C2C12 cells. The study gives insight into mechanisms of simvastatin-associated myotoxicity and provides potential targets for therapeutic intervention.

  4. VISFATIN (NAMPT) Improves In Vitro IGF1-Induced Steroidogenesis and IGF1 Receptor Signaling Through SIRT1 in Bovine Granulosa Cells.

    PubMed

    Reverchon, Maxime; Rame, Christelle; Bunel, Audrey; Chen, Wenyong; Froment, Pascal; Dupont, Joëlle

    2016-03-01

    VISFATIN is a novel adipokine, also known as a nicotinamide phosphorybosyltransferase (NAMPT), that is able to modulate different processes, including lipid and glucose metabolism, oxidative stress, inflammation, and insulin resistance. Recent data suggest that it also plays a role in reproductive function in rats, humans, and chickens. Here we identified VISFATIN in the bovine ovary and investigated the in vitro effects of this hormone on granulosa cell steroidogenesis and proliferation and oocyte maturation. By RT-PCR, immunoblotting, and immunohistochemistry, we found VISFATIN in various ovarian cells, including granulosa and theca cells, corpus luteum, and oocytes. In cultured bovine granulosa cells, we showed that IGF1 (10(-8) M) and VISFATIN (10 and 100 ng/ml) but not FSH (10(-8) M) increased mRNA expression levels of NAMPT after 48 h of stimulation. Moreover, we observed that human recombinant VISFATIN (hVisf, 10 ng/ml, 48 h) increased the release of progesterone and estradiol secretion, and this was associated with an increase in the protein level of STAR, the HSD3B activity, and the phosphorylation levels of IGF1R and MAPK ERK1/2 in the presence or absence of IGF1 (10(-8) M). All these effects were abolished when NAMPT was knocked down and when the sirtuin pharmacological inhibitors CHIC-35 (60 nM) and EX-527 (0.5 μM) were preincubated in bovine granulosa cells. Thus, in cultured bovine granulosa cells, VISFATIN improves basal and IGF1-induced steroidogenesis and IGF1 receptor signaling through SIRT1. © 2016 by the Society for the Study of Reproduction, Inc.

  5. 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.

  6. IGF-1 promotes the development and cytotoxic activity of human NK cells.

    PubMed

    Ni, Fang; Sun, Rui; Fu, Binqing; Wang, Fuyan; Guo, Chuang; Tian, Zhigang; Wei, Haiming

    2013-01-01

    Insulin-like growth factor 1 (IGF-1) is a critical regulator of many physiological functions, ranging from longevity to immunity. However, little is known about the role of IGF-1 in natural killer cell development and function. Here, we identify an essential role for IGF-1 in the positive regulation of human natural killer cell development and cytotoxicity. Specifically, we show that human natural killer cells have the ability to produce IGF-1 and that differential endogenous IGF-1 expression leads to disparate cytotoxicity in human primary natural killer cells. Moreover, miR-483-3p is identified as a critical regulator of IGF-1 expression in natural killer cells. Overexpression of miR-483-3p has an effect similar to IGF-1 blockade and decreased natural killer cell cytotoxicity, whereas inhibition of miR-483-3p has the opposite effect, which is reversible with IGF-1 neutralizing antibody. These findings indicate that IGF-1 and miR-483-3p belong to a new class of natural killer cell functional modulators and strengthen the prominent role of IGF-1 in innate immunity.

  7. Energy-preserving effects of IGF-1 antagonize starvation-induced cardiac autophagy

    PubMed Central

    Troncoso, Rodrigo; Vicencio, Jose Miguel; Parra, Valentina; Nemchenko, Andriy; Kawashima, Yuki; del Campo, Andrea; Toro, Barbra; Battiprolu, Pavan K.; Aranguiz, Pablo; Chiong, Mario; Yakar, Shoshana; Gillette, Thomas G.; Hill, Joseph A.; Abel, Evan Dale; LeRoith, Derek; Lavandero, Sergio

    2012-01-01

    Aims Insulin-like growth factor 1 (IGF-1) is known to exert cardioprotective actions. However, it remains unknown if autophagy, a major adaptive response to nutritional stress, contributes to IGF-1-mediated cardioprotection. Methods and results We subjected cultured neonatal rat cardiomyocytes, as well as live mice, to nutritional stress and assessed cell death and autophagic rates. Nutritional stress induced by serum/glucose deprivation strongly induced autophagy and cell death, and both responses were inhibited by IGF-1. The Akt/mammalian target of rapamycin (mTOR) pathway mediated the effects of IGF-1 upon autophagy. Importantly, starvation also decreased intracellular ATP levels and oxygen consumption leading to AMP-activated protein kinase (AMPK) activation; IGF-1 increased mitochondrial Ca2+ uptake and mitochondrial respiration in nutrient-starved cells. IGF-1 also rescued ATP levels, reduced AMPK phosphorylation and increased p70S6K phosphorylation, which indicates that in addition to Akt/mTOR, IGF-1 inhibits autophagy by the AMPK/mTOR axis. In mice harbouring a liver-specific igf1 deletion, which dramatically reduces IGF-1 plasma levels, AMPK activity and autophagy were increased, and significant heart weight loss was observed in comparison with wild-type starved animals, revealing the importance of IGF-1 in maintaining cardiac adaptability to nutritional insults in vivo. Conclusion Our data support the cardioprotective actions of IGF-1, which, by rescuing the mitochondrial metabolism and the energetic state of cells, reduces cell death and controls the potentially harmful autophagic response to nutritional challenges. IGF-1, therefore, may prove beneficial to mitigate damage induced by excessive nutrient-related stress, including ischaemic disease in multiple tissues. PMID:22135164

  8. Experimental approach to IGF-1 therapy in CCl4-induced acute liver damage in healthy controls and mice with partial IGF-1 deficiency.

    PubMed

    Morales-Garza, Luis A; Puche, Juan E; Aguirre, Gabriel A; Muñoz, Úrsula; García-Magariño, Mariano; De la Garza, Rocío G; Castilla-Cortazar, Inma

    2017-05-04

    Cell necrosis, oxidative damage, and fibrogenesis are involved in cirrhosis development, a condition in which insulin-like growth factor 1 (IGF-1) levels are diminished. This study evaluates whether the exogenous administration of low doses of IGF-1 can induce hepatoprotection in acute carbon tetrachloride (CCl4)-induced liver damage compared to healthy controls (Wt Igf (+/+)). Additionally, the impact of IGF-1 deficiency on a damaged liver was investigated in mice with a partial deficit of this hormone (Hz Igf1 (+/-)). Three groups of 25 ± 5-week-old healthy male mice (Wt Igf (+/+)) were included in the protocol: untreated controls (Wt). Controls that received CCl4 (Wt + CCl4) and Wt + CCl4 were treated subcutaneously with IGF-1 (2 µg/100 g body weight/day) for 10 days (Wt + CCl4 + IGF1). In parallel, three IGF-1-deficient mice (Hz Igf1 (+/-)) groups were studied: untreated Hz, Hz + CCl4, and Hz + CCl4 + IGF-1. Microarray and real-time quantitative polymerase chain reaction (RT-qPCR) analyses, serum aminotransferases levels, liver histology, and malondialdehyde (MDA) levels were assessed at the end of the treatment in all groups. All data represent mean ± SEM. An altered gene coding expression pattern for proteins of the extracellular matrix, fibrosis, and cellular protection were found, as compared to healthy controls, in which IGF-1 therapy normalized in the series including healthy mice. Liver histology showed that Wt + CCl4 + IGF1 mice had less oxidative damage, fibrosis, lymphocytic infiltrate, and cellular changes when compared to the Wt + CCl4. Moreover, there was a correlation between MDA levels and the histological damage score (Pearson's r = 0.858). In the IGF-1-deficient mice series, similar findings were identified, denoting a much more vulnerable hepatic parenchyma. IGF1 treatment improved the biochemistry, histology, and genetic expression of pro-regenerative and cytoprotective factors in both series (healthy and IGF-1

  9. 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.

  10. 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. © 2013 Wiley Periodicals, Inc.

  11. IGF1 potentiates the pro-inflammatory response in human peripheral blood mononuclear cells via MAPK.

    PubMed

    Wolters, Thalijn Liliana Catharina; Netea, Mihai Gheorghe; Hermus, Adrianus Rudolfus Marinus Maria; Smit, Johannes Willem Adriaan; Netea-Maier, Romana Teodora

    2017-08-01

    Acromegaly is characterized by growth hormone (GH) and insulin-like growth factor 1 (IGF1) excess and is accompanied by an increased cardiovascular diseases (CVD) risk. As innate immune responses are crucial in CVD development, and IGF1 is linked to subclinical inflammation, we hypothesized that GH/IGF1 excess contributes to CVD development by potentiating systemic inflammation. We aimed to assess the effects of GH/IGF1 on inflammatory cytokine production. Whole blood from acromegaly patients and healthy volunteers and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were stimulated with Toll-like receptor (TLR) ligands, with or without adding GH or IGF1 (in PBMC). Cytokine concentrations were measured by ELISA. The underlying signalling pathways were investigated by the inhibition of downstream targets of the IGF1 receptor. The following results were obtained. GH or IGF1 alone did not influence cytokine production in PBMCs. GH did not affect TLR-induced cytokine production, but co-stimulation with IGF1 dose dependently increased the TLR ligand-induced production of IL6 (P < 0.01), TNF alpha (P = 0.02) and IFNg (P < 0.01), as well as the production of the anti-inflammatory cytokine IL10 (P = 0.01). IGF1 had no effect on IL1B, IL17 and IL22 production. Inhibition of the MAPK pathway, but not mTOR, completely abrogated the synergistic effect of IGF1 on the LPS-induced IL6 and TNF alpha production. In whole blood of acromegaly patients, ex vivo IL6 production was increased (P < 0.01). In conclusion, IGF1, but not GH, has pro-inflammatory effects, probably via the MAPK signalling pathway and might be involved in the pathogenesis of atherosclerosis in acromegaly. The increased IL10 production possibly counteracts the pro-inflammatory effects. © 2017 Society for Endocrinology.

  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. Partial IGF-1 deficiency induces brain oxidative damage and edema, which are ameliorated by replacement therapy.

    PubMed

    Puche, Juan E; Muñoz, Úrsula; García-Magariño, Mariano; Sádaba, María C; Castilla-Cortázar, Inma

    2016-01-01

    Insulin-like growth factor 1 (IGF-1) induces multiple cytoprotective effects on every tissue, including the brain. Since the mechanisms by which IGF-1 produces neuroprotection are not fully understood, the aim of this work was to delve into the underlying mechanisms. IGF-1 deficient mice (Hz) were compared with wild type (WT) and Hz mice treated with low doses of IGF-1 (2 µg/100 g body weight/day) for 10 days (Hz + IGF). Gene expression, quantitative PCR, histology, and magnetic resonance imaging were performed in the three groups. IGF-1 deficiency induced increased oxidative damage determined by markers of lipid peroxidation and hypoxia, as well as gene expression of heat shock proteins, antioxidant enzymes, and molecules involved in inflammation, apoptosis, and mitochondrial protection. These changes correlated with edema and learning impairment in Hz mice. IGF-1 therapy improved all these alterations. In conclusion, IGF-1 deficiency is responsible for increased brain oxidative damage, edema, and impaired learning and memory capabilities which are rescued by IGF-1 replacement therapy. © 2016 International Union of Biochemistry and Molecular Biology.

  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. 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

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

    PubMed Central

    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 () in mitochondria, either by chemical inhibition of complex I or by genetic silencing of -dismutating mitochondrial Sod2. The -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 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 -induced IGF-1 resistance and rescued the ageing skin phenotype. We thus identify previously unreported signature events with , PTP1B, and PTEN as promising targets for drug development to prevent IGF-1 resistance-related pathologies. PMID:25520316

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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. © 2014 UICC.

  4. 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

  5. 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.

  6. 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

  7. Esculetin induces apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-mediated mitochondrial pathways.

    PubMed

    Li, Juan; Li, Shuang; Wang, Xiuli; Wang, Hongxin

    2017-07-01

    Esculetin (6,7-dihydroxycoumarin) is a coumarin derivative extracted from natural plants and has been reported to have anticancer activity. However, the mechanism by which esculetin prevents human hepatic cancer cell growth is still largely unknown. In this study, we investigated the effect of esculetin on human hepatocellular carcinoma (HCC) SMMC-7721 cells and explored the cell signal mechanism. Our data indicated that esculetin induced apoptosis in SMMC-7721 cells, which were supported by DAPI staining and Annexin V/PI staining. Meanwhile, esculetin increased the activities of caspase-3 and caspase-9, promoted bax expression, decreased bcl-2 expression, and triggered collapse of mitochondrial membrane potential, and increased cytochrome c release from mitochondria. In addition, the inactivation of IGF-1, PI3K, and Akt was observed after esculetin administration. Furthermore, pretreatment with IGF-1 before esculetin administration abrogated the pro-apoptotic effects of esculetin, while PI3K inhibitor increased the pro-apoptotic effects of esculetin. These results indicated that esculetin induced the apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-regulated mitochondrial dysfunction.

  8. IR and IGF-1R expression affects insulin induced proliferation and DNA damage.

    PubMed

    Othman, Eman Maher; Altabaa, Tahanee; Hintzsche, Henning; Stopper, Helga

    2017-03-01

    Diabetes mellitus type 2 is in its prediagnostic and early phase characterized by hyperinsulinemia. Previously, we pointed out hyperinsulinemia as a potential link between diabetes mellitus and the increased cancer risk that is associated with this disease through its induction of oxidative stress and DNA damage. In the present study, we address the relationship between the induction of proliferation and genomic damage in vitro in cell lines with different expression of the insulin and the IGF-1 receptors after treating the cells with insulin and the insulin analog glargine. Contribution of the IGF-1 receptor was further examined by application of the IGF-1R inhibitor ((5R,5aS,8aR,9R)-9-hydroxy-5,8,8a,9-tetrahydro-5-(3,4,5-trimethoxyphenyl)-furo[3_,4_:6,7]-naphtho[2,3-d]-1,3-dioxol-6(5aH)-one) (PPP). Insulin as well as insulin glargine stimulated cell proliferation in IGF-receptor-dominated MCF-7 cells and not in insulin receptor-dominated BT-474 cells and PPP attenuated this effect. Both insulins induced DNA damage which was reduced by PPP in MCF-7 cells only. Overall, we showed in this study that high levels of insulin and insulin glargine can enhance cell proliferation in cells which highly express IGF-1 receptor and induce DNA damage in cells with high and also in those with low IGF-1 receptor levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Inhibition of IGF1-R overcomes IGFBP7-induced chemotherapy resistance in T-ALL.

    PubMed

    Bartram, Isabelle; Erben, Ulrike; Ortiz-Tanchez, Jutta; Blunert, Katja; Schlee, Cornelia; Neumann, Martin; Heesch, Sandra; Baldus, Claudia D

    2015-10-08

    inhibiting effect of IGFBP7 by G0/G1 arrest and a drug resistance-inducing effect of IGFBP7 against vincristine and asparaginase in T-ALL. These results provide a model for the previously observed association between high IGFBP7 expression and chemotherapy failure in T-ALL patients. Since the resistance against vincristine was abolished by IGF1-R inhibition, IGFBP7 could serve as biomarker for patients who may benefit from therapies including IGF1-R inhibitors in combination with chemotherapy.

  10. 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

  11. 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.

  12. 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.

  13. IGF-1 protects against Aβ25-35-induced neuronal cell death via inhibition of PUMA expression and Bax activation.

    PubMed

    Hou, Xunyao; Jin, Yan; Chen, Jian; Hong, Yan; Luo, Dingzhen; Yin, Qingqing; Liu, Xueping

    2017-01-10

    Amyloid-β-peptide (Aβ) is considered to be the toxic species in AD and causes cell death in the affected areas of patient's brain. Insulin-like growth factor 1 (IGF-1) has been reported to attenuate Aβ toxicity in neuronal cells. However, the molecular mechanisms involved in the neuroprotective function of IGF-1 remain largely unknown. In the present study, we for the first time demonstrated that IGF-1 protects against Aβ-induced neurotoxicity via inhibition of PUMA expression and Bax activation. We found that IGF-1 could activate Akt, which in turn inhibited Aβ-induced FOXO3a nuclear translocation and thus decreased the binding ability of FOXO3a to PUMA promoter, leading to decreased PUMA expression. In addition, IGF-1 inhibited the translocation of Bax to the mitochondria induced by Aβ. Notably, addition of wortmannin, a specific inhibitor of PI3K, significantly abolished the neuroprotective effect of IGF-1, suggesting that IGF-1 exerts its anti-apoptotic effect depend on PI3K activity. Our findings may provide new insights into molecular mechanisms mediated by IGF-1 in cell survival against Aβ-induced apoptosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Locally expressed IGF1 propeptide improves mouse heart function in induced dilated cardiomyopathy by blocking myocardial fibrosis and SRF-dependent CTGF induction

    PubMed Central

    Touvron, Melissa; Escoubet, Brigitte; Mericskay, Mathias; Angelini, Aude; Lamotte, Luciane; Santini, Maria Paola; Rosenthal, Nadia; Daegelen, Dominique; Tuil, David; Decaux, Jean-François

    2012-01-01

    SUMMARY Cardiac fibrosis is critically involved in the adverse remodeling accompanying dilated cardiomyopathies (DCMs), which leads to cardiac dysfunction and heart failure (HF). Connective tissue growth factor (CTGF), a profibrotic cytokine, plays a key role in this deleterious process. Some beneficial effects of IGF1 on cardiomyopathy have been described, but its potential role in improving DCM is less well characterized. We investigated the consequences of expressing a cardiac-specific transgene encoding locally acting IGF1 propeptide (muscle-produced IGF1; mIGF1) on disease progression in a mouse model of DCM [cardiac-specific and inducible serum response factor (SRF) gene disruption] that mimics some forms of human DCM. Cardiac-specific mIGF1 expression substantially extended the lifespan of SRF mutant mice, markedly improved cardiac functions, and delayed both DCM and HF. These protective effects were accompanied by an overall improvement in cardiomyocyte architecture and a massive reduction of myocardial fibrosis with a concomitant amelioration of inflammation. At least some of the beneficial effects of mIGF1 transgene expression were due to mIGF1 counteracting the strong increase in CTGF expression within cardiomyocytes caused by SRF deficiency, resulting in the blockade of fibroblast proliferation and related myocardial fibrosis. These findings demonstrate that SRF plays a key role in the modulation of cardiac fibrosis through repression of cardiomyocyte CTGF expression in a paracrine fashion. They also explain how impaired SRF function observed in human HF promotes fibrosis and adverse cardiac remodeling. Locally acting mIGF1 efficiently protects the myocardium from these adverse processes, and might thus represent a therapeutic avenue to counter DCM. PMID:22563064

  15. Advanced glycation end products promote human aortic smooth muscle cell calcification in vitro via activating NF-κB and down-regulating IGF1R expression.

    PubMed

    Wang, Yi; Zhang, Zhen-yu; Chen, Xiao-qing; Wang, Xiang; Cao, Heng; Liu, Shao-wen

    2013-04-01

    To investigate the effects of advanced glycation end products (AGEs) on calcification in human aortic smooth muscle cells (HASMCs) in vitro and the underlying mechanisms. AGEs were artificially prepared. Calcification of HASMCs was induced by adding inorganic phosphate (Pi, 2 mmol/L) in the media, and observed with Alizarin red staining. The calcium content in the supernatant was measured using QuantiChrome Calcium Assay Kit. Expression of the related mRNAs and proteins was analyzed using real-time PCR and Western blot, respectively. Chromatin immunoprecipitation (ChIP) assay was used to detect the binding of NF-κB to the putative IGF1R promoter. AGEs (100 μg/mL) significantly enhanced Pi-induced calcification and the levels of osteocalcin and Cbfα1 in HASMCs. Furthermore, the treatment decreased the expression of insulin-like growth factor 1 receptor (IGF1R). Over-expression of IGF1R in HASMCs suppressed the AGEs-induced increase in calcium deposition. When IGF1R expression was knocked down in HASMCs, AGEs did not enhance the calcium deposition. Meanwhile, AGEs time-dependently decreased the amounts of IκBα and Flag-tagged p65 in the cytoplasmic extracts, and increased the amount of nuclear p65 in HASMCs. In the presence of NF-κB inhibitor PDTC (50 μmol/L), the AGEs-induced increase in calcium deposition was blocked. Over-expression of p65 significantly enhanced Pi-induced mineralization, but suppressed IGF1R mRNA level. Knockdown of p65 suppressed the AGEs-induced increase in calcium deposition, and rescued the IGF1R expression. The ChIP analysis revealed that NF-κB bound the putative IGF1R promoter at position -230 to -219 bp. The inhibition of IGF1R by NF-κB was abolished when IGF1R reporter plasmid contained mutated binding sequence for NF-κB or an NF-κB reporter vector. The results demonstrate that AGEs promote calcification of human aortic smooth muscle cells in vitro via activation of NF-κB and down-regulation of IGF1R expression.

  16. 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.

  17. 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

  18. S-nitrosylation of the IGF-1 receptor disrupts the cell proliferative action of IGF-1.

    PubMed

    Okada, Kazushi; Zhu, Bao-Ting

    2017-09-30

    The insulin-like growth factor 1 receptor (IGF-1R) is a disulfide-linked heterotetramer containing two α-subunits and two β-subunits. Earlier studies demonstrate that nitric oxide (NO) can adversely affect IGF-1 action in the central nervous system. It is known that NO can induce S-nitrosylation of the cysteine residues in proteins, thereby partly contributing to the regulation of protein function. In the present study, we sought to determine whether S-nitrosylation of the cysteine residues in IGF-1R is an important post-translational modification that regulates its response to IGF-1. Using cultured SH-SY5Y human neuroblastoma cells as an in vitro model, we found that treatment of cells with S-nitroso-cysteine (SNOC), a NO donor that can nitrosylate the cysteine residues in proteins, induces S-nitrosylation of the β subunit of IGF-1R but not its α-subunit. IGF-1Rβ S-nitrosylation by SNOC is coupled with increased dissociation of the IGF-1R protein complex. In addition, disruption of the IGF-1R function resulting from S-nitrosylation of the IGF-1Rβ subunit is associated with disruption of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways. Further, we observed that SNOC-induced IGF-1Rβ S-nitrosylation results in a dose-dependent inhibition of cell proliferation and survival. Together, these results suggest that elevated nitrosative stress may result in dysfunction of cellular IGF-1R signaling through S-nitrosylation of the cysteine residues in the IGF-1Rβ subunit, thereby disrupting the downstream PI3K and MAPK signaling functions and ultimately resulting in inhibition of cell proliferation and survival. Copyright © 2017. Published by Elsevier Inc.

  19. 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

  20. 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

  1. 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

  2. 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

  3. The Effects of IGF-1 on Trk Expressing DRG Neurons with HIV-gp120- Induced Neurotoxicity.

    PubMed

    Li, Hao; Liu, Zhen; Chi, Heng; Bi, Yanwen; Song, Lijun; Liu, Huaxiang

    2016-01-01

    HIV envelope glycoprotein gp120 is the main protein that causes HIVassociated sensory neuropathy. However, the underlying mechanisms of gp120-induced neurotoxicity are still unclear. There are lack effective treatments for relieving HIV-related neuropathic symptoms caused by gp120-induced neurotoxicity. In the present study, tyrosine kinase receptor (Trk)A, TrkB, and TrkC expression in primary cultured dorsal root ganglion (DRG) neurons with gp120-induced neurotoxicity was investigated. The effects of IGF-1 on distinct Trk-positive DRG neurons with gp120-induced neurotoxicity were also determined. The results showed that gp120 not only dose-dependently induced DRG neuronal apoptosis and inhibited neuronal survival and neurite outgrowth, but also decreased distinct Trk expression levels. IGF-1 rescued DRG neurons from apoptosis and improved neuronal survival of gp120 neurotoxic DRG neurons in vitro. IGF-1 also improved TrkA and TrkB, but not TrkC, expression in gp120 neurotoxic conditions. The effects of IGF-1 could be blocked by preincubation with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. These results suggested that gp120 may have a wide range of neurotoxicity on different subpopulations of DRG neurons, while IGF-1 might only relieve some subpopulations of DRG neurons with gp120-induced neurotoxicity. These data provide novel information of mechanisms of gp120 neurotoxicity on primary sensory neurons and the potential therapeutic effects of IGF-1 on gp120-induced neurotoxicity.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. Obesity and intestinal epithelial deletion of the insulin receptor, but not the IGF 1 receptor, affect radiation-induced apoptosis in colon

    PubMed Central

    Santoro, M. Agostina; Blue, R. Eric; Andres, Sarah F.; Mah, Amanda T.; Van Landeghem, Laurianne

    2015-01-01

    Current views suggest that apoptosis eliminates genetically damaged cells that may otherwise form tumors. Prior human studies link elevated insulin and reduced apoptosis to risk of colorectal adenomas. We hypothesized that hyperinsulinemia associated with obesity would lead to reduced colon epithelial cell (CEC) apoptosis after radiation and that this effect would be altered by deletion of the insulin-like growth factor (IGF) 1 receptor (IGF1R) or the insulin receptor (IR). Mice with villin-Cre-mediated IGF1R or IR deletion in CECs and floxed littermates were fed a high-fat diet to induce obesity and hyperinsulinemia or control low-fat chow. Mice were exposed to 5-Gy abdominal radiation to induce DNA damage and euthanized 4 h later for evaluation of apoptosis by localization of cleaved caspase-3. Obese mice exhibited decreased apoptosis of genetically damaged CECs. IGF1R deletion did not affect CEC apoptosis in lean or obese animals. In contrast, IR loss increased CEC apoptosis in both diet groups but did not prevent antiapoptotic effects of obesity. Levels of p53 protein were significantly reduced in CECs of obese mice with intact IR but increased in both lean and obese mice without IR. Levels of mRNAs encoding proapoptotic Perp and the cell cycle inhibitor Cdkn1b/p27 were reduced in CECs of obese mice and increased in lean mice lacking IR. Together, our studies provide novel evidence for antiapoptotic roles of obesity and IR, but not IGF1R, in colonic epithelium after DNA damage. However, neither IR nor IGF1R deletion prevented a reduction in radiation-induced CEC apoptosis during obesity and hyperinsulinemia. PMID:26251471

  10. 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

  11. Analysis of expression patterns of IGF-1, caspase-3 and HSP-70 in developing human tooth germs.

    PubMed

    Kero, Darko; Kalibovic Govorko, Danijela; Medvedec Mikic, Ivana; Vukojevic, Katarina; Cigic, Livia; Saraga-Babic, Mirna

    2015-10-01

    To analyze expression patterns of IGF-1, caspase-3 and HSP-70 in human incisor and canine tooth germs during the late bud, cap and bell stages of odontogenesis. Head areas or parts of jaw containing teeth from 10 human fetuses aged between 9th and 20th developmental weeks were immunohistochemically analyzed using IGF-1, active caspase-3 and HSP-70 markers. Semi-quantitative analysis of each marker's expression pattern was also performed. During the analyzed period, IGF-1 and HSP-70 were mostly expressed in enamel organ. As development progressed, expression of IGF-1 and HSP-70 became more confined to differentiating tissues in the future cusp tip area, as well as in highly proliferating cervical loops. Few apoptotic bodies highly positive to active caspase-3 were observed in enamel organ and dental papilla from the cap stage onward. However, both enamel epithelia moderately expressed active caspase-3 throughout the investigated period. Expression patterns of IGF-1, active caspase-3 and HSP-70 imply importance of these factors for early human tooth development. IGF-1 and HSP-70 have versatile functions in control of proliferation, differentiation and anti-apoptotic protection of epithelial parts of human enamel organ. Active caspase-3 is partially involved in formation and apoptotic removal of primary enamel knot, although present findings might reflect its ability to perform other non-death functions such as differentiation of hard dental tissues secreting cells and guidance of ingrowth of proliferating cervical loops. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Downregulation of IGF-1 receptor occurs after hepatic linage commitment during hepatocyte differentiation from human embryonic stem cells.

    PubMed

    Waraky, Ahmed; Aleem, Eiman; Larsson, Olle

    2016-09-30

    The insulin-like growth factor 1 receptor (IGF-1R) has been suggested to be involved in hepatocyte differentiation. Human hepatocyte cancer cells and stem cells are known to express IGF-1R whereas normal hepatocytes do not. In the present study we optimized a differentiation protocol and verified the different stages by established markers. The expression levels of IGF-1R and major downstream signaling proteins during differentiation from human embryonic stem cells (hESC) to mature hepatocytes were investigated. We could only demonstrate a minor decrease in IGF-1R expression during endodermal differentiation compared to hESC, but declined substantially (>50%) after hepatic lineage commitment during the hepatocyte specification and maturation stages. This downregulation was paralleled by an upregulation of ERK 1/2, AKT and insulin substrate-1. Neither inhibition nor activation of IGF-1R had any essential effect on endoderm differentiation of human embryonic stem cells. Therefore, our data suggest that IGF-1R downregulation may have a regulatory impact after initiation of hepatic lineage commitment. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  13. 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.

  14. 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.

  15. IGF1R signalling and its inhibition.

    PubMed

    Riedemann, J; Macaulay, V M

    2006-12-01

    The type 1 IGF receptor (IGF1R) is a transmembrane tyrosine kinase that is frequently overexpressed by tumours, and mediates proliferation and apoptosis protection. IGF signalling also influences hypoxia signalling, protease secretion, tumour cell motility and adhesion, and thus can affect the propensity for invasion and metastasis. Therefore, the IGF1R is now an attractive anti-cancer treatment target. This review outlines the effects of IGF1R activation in tumour cells, and will describe the strategies that are available to block IGF signalling, both as investigational tools and as novel anti-cancer therapeutics. Design of specific IGF1R inhibitors has been problematic due to close homology with the insulin receptor, but recently it has proved possible to design selective IGF1R inhibitors. These compounds and IGF1R antibodies are showing promise in preclinical models of human cancer, and several agents are now in early phase clinical trials. Both classes of agents affect insulin receptor signalling, either by direct kinase inhibition or antibody-induced insulin receptor downregulation. This effect may lead to clinical toxicity, but could be therapeutically beneficial in blocking signalling via variant insulin receptors capable of a mitogenic response to IGF-II. Specificity for IGF1R targeting can be achieved by antisense and siRNA-mediated IGF1R downregulation; these approaches have undoubted utility as research tools, and may in future generate nucleic-acid-based therapeutics. It will be important to use data from preclinical and early clinical trials to establish the molecular correlates of sensitivity to IGF1R blockade, and the optimum means of combining this new approach with standard treatment modalities.

  16. 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.

  17. 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

  18. IGF-1 Attenuates Hypoxia-Induced Atrophy but Inhibits Myoglobin Expression in C2C12 Skeletal Muscle Myotubes.

    PubMed

    Peters, Eva L; van der Linde, Sandra M; Vogel, Ilse S P; Haroon, Mohammad; Offringa, Carla; de Wit, Gerard M J; Koolwijk, Pieter; van der Laarse, Willem J; Jaspers, Richard T

    2017-09-01

    Chronic hypoxia is associated with muscle wasting and decreased oxidative capacity. By contrast, training under hypoxia may enhance hypertrophy and increase oxidative capacity as well as oxygen transport to the mitochondria, by increasing myoglobin (Mb) expression. The latter may be a feasible strategy to prevent atrophy under hypoxia and enhance an eventual hypertrophic response to anabolic stimulation. Mb expression may be further enhanced by lipid supplementation. We investigated individual and combined effects of hypoxia, insulin-like growth factor (IGF)-1 and lipids, in mouse skeletal muscle C2C12 myotubes. Differentiated C2C12 myotubes were cultured for 24 h under 20%, 5% and 2% oxygen with or without IGF-1 and/or lipid treatment. In culture under 20% oxygen, IGF-1 induced 51% hypertrophy. Hypertrophy was only 32% under 5% and abrogated under 2% oxygen. This was not explained by changes in expression of genes involved in contractile protein synthesis or degradation, suggesting a reduced rate of translation rather than of transcription. Myoglobin mRNA expression increased by 75% under 5% O₂ but decreased by 50% upon IGF-1 treatment under 20% O₂, compared to control. Inhibition of mammalian target of rapamycin (mTOR) activation using rapamycin restored Mb mRNA expression to control levels. Lipid supplementation had no effect on Mb gene expression. Thus, IGF-1-induced anabolic signaling can be a strategy to improve muscle size under mild hypoxia, but lowers Mb gene expression.

  19. IGF-1 Attenuates Hypoxia-Induced Atrophy but Inhibits Myoglobin Expression in C2C12 Skeletal Muscle Myotubes

    PubMed Central

    Vogel, Ilse S. P.; Offringa, Carla; de Wit, Gerard M. J.; Koolwijk, Pieter; van der Laarse, Willem J.; Jaspers, Richard T.

    2017-01-01

    Chronic hypoxia is associated with muscle wasting and decreased oxidative capacity. By contrast, training under hypoxia may enhance hypertrophy and increase oxidative capacity as well as oxygen transport to the mitochondria, by increasing myoglobin (Mb) expression. The latter may be a feasible strategy to prevent atrophy under hypoxia and enhance an eventual hypertrophic response to anabolic stimulation. Mb expression may be further enhanced by lipid supplementation. We investigated individual and combined effects of hypoxia, insulin-like growth factor (IGF)-1 and lipids, in mouse skeletal muscle C2C12 myotubes. Differentiated C2C12 myotubes were cultured for 24 h under 20%, 5% and 2% oxygen with or without IGF-1 and/or lipid treatment. In culture under 20% oxygen, IGF-1 induced 51% hypertrophy. Hypertrophy was only 32% under 5% and abrogated under 2% oxygen. This was not explained by changes in expression of genes involved in contractile protein synthesis or degradation, suggesting a reduced rate of translation rather than of transcription. Myoglobin mRNA expression increased by 75% under 5% O2 but decreased by 50% upon IGF-1 treatment under 20% O2, compared to control. Inhibition of mammalian target of rapamycin (mTOR) activation using rapamycin restored Mb mRNA expression to control levels. Lipid supplementation had no effect on Mb gene expression. Thus, IGF-1-induced anabolic signaling can be a strategy to improve muscle size under mild hypoxia, but lowers Mb gene expression. PMID:28862673

  20. 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.

  1. 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.

  2. 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.

  3. The quinic acid derivative KZ-41 prevents glucose-induced caspase-3 activation in retinal endothelial cells through an IGF-1 receptor dependent mechanism

    PubMed Central

    He, Hui; Weir, Rebecca L.; Toutounchian, Jordan J.; Pagadala, Jayaprakash; Steinle, Jena J.; Baudry, Jerome; Miller, Duane D.

    2017-01-01

    Retinal microaneurysms, an early disease manifestation of diabetic retinopathy, are associated with retinal endothelial cell (REC) death and macular edema. We previously demonstrated that a quinic acid (QA) analog, KZ-41, promoted REC survival by blunting stress-induced p38 MAPK activation. Herein, we sought to expand our understanding of the pro-survival signal transduction pathways actuated by KZ-41. Using human RECs exposed to high glucose (25 mM, 72 hours), we demonstrated that KZ-41 blocks caspase-3 activation by triggering phosphorylation of the PI3K regulatory subunit (p85; Tyr458) and its downstream target Akt (Ser473). Akt signal transduction was accompanied by autophosphorylation of the receptor tyrosine kinase, insulin growth factor-1 receptor (IGF-1R). IGF-1R knockdown using either the tyrosine kinase inhibitor AG1024 or silencing RNA abolished KZ-41’s pro-survival effect. Under high glucose stress, caspase-3 activation correlated with elevated ERK1/2 phosphorylation and decreased insulin receptor substrate-1 (IRS-1) levels. KZ-41 decreased ERK1/2 phosphorylation and reversed the glucose-dependent reduction in IRS-1. To gain insight into the mechanistic basis for IGF-1R activation by KZ-41, we used molecular modeling and docking simulations to explore a possible protein:ligand interaction between the IGF-1R kinase domain and KZ-41. Computational investigations suggest two possible KZ-41 binding sites within the kinase domain: a region with high homology to the insulin receptor contains one potential allosteric binding site, and another potential site on the other side of the kinase domain, near the hinge domain. These data, together with previous proof-of-concept efficacy studies demonstrating KZ-41 mitigates pathologic retinal neovascularization in the murine oxygen-induced retinopathy model, suggests that QA derivatives may offer therapeutic benefit in ischemic retinopathies. PMID:28796787

  4. 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

  5. Chondroprotective effects of a proanthocyanidin rich Amazonian genonutrient reflects direct inhibition of matrix metalloproteinases and upregulation of IGF-1 production by human chondrocytes

    PubMed Central

    Miller, Mark JS; Bobrowski, Paul; Shukla, Meenakshi; Gupta, Kalpana; Haqqi, Tariq M

    2007-01-01

    Background The Amazonian medicinal plant Sangre de grado (Croton palanostigma) has traditional applications for the treatment of wound healing and inflammation. We sought to characterize two extracts (progrado and zangrado) in terms of safety and oligomeric proanthocyanidin chain length. Additionally progrado was evaluated for antioxidant activity and possible chondroprotective actions. Methods Acute oral safety and toxicity was tested in rats according under OECD protocol number 420. The profile of proanthocyanidin oligomers was determined by HPLC and progrado's antioxidant activity quantified by the ORAC, NORAC and HORAC assays. Human cartilage explants, obtained from surgical specimens, were used to assess chondroproteciton with activity related to direct inhibitory effects on human matrix metalloproteinase (MMP, gelatinolytic) activity using synovial fluid and chondrocytes activated with IL-1β (10 ng/ml). Additionally, progrado (2–10 μg/ml) was tested for its ability to maintain optimal IGF-1 transcription and translation in cartilage explants and cultured chondrocytes. Results Both progrado and zangrado at doses up to 2000 mg/kg (po) displayed no evidence of toxicity. Oligomeric proanthocyanidin content was high for both progrado (158 mg/kg) and zangrado (124 mg/kg), with zangrado almost entirely composed of short oligomers (<6 mer), whereas the majority of oligomers in progrado exceeded 10 mers. Progrado was a remarkably potent antioxidant in the standardized tests ORAC, NORAC and HORAC. Progrado was exceptionally effective in reducing both basal and IL-1β induced glycosaminoglycan release from human cartilage explants at concentrations that also directly blocked the gelatinolytic activity of MMP-2 and MMP-9. Progrado prevented IL-1β induced suppression of IGF-1 production from human cartilage explants as well as stimulating basal IGF-1 production (P < 0.05). Comparable changes in IGF-1 gene expression were noted in cultured human chondrocytes

  6. 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.

  7. 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.

  8. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. 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.

  10. Insulin like growth factor-1 (IGF-1) causes overproduction of IL-8, an angiogenic cytokine and stimulates neovascularization in isoproterenol-induced myocardial infarction in rats.

    PubMed

    Haleagrahara, Nagaraja; Chakravarthi, Srikumar; Mathews, Lisa

    2011-01-01

    Angiogenesis factors are produced in response to hypoxic or ischemic insult at the site of pathology, which will cause neovascularization. Insulin like growth factor-1 (IGF-1) exerts potent proliferative, angiogenic and anti-apoptotic effects in target tissues. The present study was aimed to evaluate the effects of IGF-1 on circulating level of angiogenic cytokine interleukin-8 (IL-8), in experimentally-induced myocardial ischemia in rats. Male Sprague-Dawley rats were divided into control, IGF-1 treated (2 μg/kg/day subcutaneously, for 5 and 10 days), isoproterenol (ISO) treated (85 mg/kg, subcutaneously for two days) and ISO with IGF-1 treated (for 5 and 10 days). Heart weight, serum IGF-1, IL-8 and cardiac marker enzymes (CK-MB and LDH) were recorded after 5 and 10 days of treatment. Histopathological analyses of the myocardium were also done. There was a significant increase in serum cardiac markers with ISO treatment indicating myocardial infarction in rats. IGF-1 level increased significantly in ISO treated groups and the level of IGF-1 was significantly higher after 10 days of treatment. IL-8 level increased significantly after ISO treatment after 5 and 10 days and IGF-1 concurrent treatment to ISO rats had significantly increased IL-8 levels. Histopathologically, myocyte necrosis and nuclear pyknosis were reduced significantly in IGF-1 treated group and there were numerous areas of capillary sprouting suggestive of neovascularization in the myocardium. Thus, IGF-1 protects the ischemic myocardium with increased production of circulating angiogenic cytokine, IL-8 and increased angiogenesis.

  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. IGF1R blockade with ganitumab results in systemic effects on the GH–IGF axis in mice

    PubMed Central

    Moody, Gordon; Beltran, Pedro J; Mitchell, Petia; Cajulis, Elaina; Chung, Young-Ah; Hwang, David; Kendall, Richard; Radinsky, Robert; Cohen, Pinchas; Calzone, Frank J

    2014-01-01

    Ganitumab is a fully human MAB to the human type 1 IGF receptor (IGF1R). Binding assays showed that ganitumab recognized murine IGF1R with sub-nanomolar affinity (KD=0.22 nM) and inhibited the interaction of murine IGF1R with IGF1 and IGF2. Ganitumab inhibited IGF1-induced activation of IGF1R in murine lungs and CT26 murine colon carcinoma cells and tumors. Addition of ganitumab to 5-fluorouracil resulted in enhanced inhibition of tumor growth in the CT26 model. Pharmacological intervention with ganitumab in naïve nude mice resulted in a number of physiological changes described previously in animals with targeted deletions of Igf1 and Igf1r, including inhibition of weight gain, reduced glucose tolerance and significant increase in serum levels of GH, IGF1 and IGFBP3. Flow cytometric analysis identified GR1/CD11b-positive cells as the highest IGF1R-expressing cells in murine peripheral blood. Administration of ganitumab led to a dose-dependent, reversible decrease in the number of peripheral neutrophils with no effect on erythrocytes or platelets. These findings indicate that acute IGF availability for its receptor plays a critical role in physiological growth, glucose metabolism and neutrophil physiology and support the presence of a pituitary IGF1R-driven negative feedback loop that tightly regulates serum IGF1 levels through Gh signaling. PMID:24492468

  14. 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

  15. Folate deprivation induces cell cycle arrest at G0/G1 phase and apoptosis in hippocampal neuron cells through down-regulation of IGF-1 signaling pathway.

    PubMed

    Yang, Yang; Li, Xi; Sun, Qinwei; He, Bin; Jia, Yimin; Cai, Demin; Zhao, Ruqian

    2016-10-01

    Folate deficiency contributes to impaired adult hippocampal neurogenesis, yet the mechanisms remain unclear. Here we use HT-22 hippocampal neuron cells as model to investigate the effect of folate deprivation (FD) on cell proliferation and apoptosis, and to elucidate the underlying mechanism. FD caused cell cycle arrest at G0/G1 phase and increased the rate of apoptosis, which was associated with disrupted expression of folate transport and methyl transfer genes. FOLR1 and SLC46A1 were (P<0.01) down-regulated, while SLC19A1 was up-regulated (P<0.01) in FD group. FD cells exhibited significantly (P<0.05) higher protein content of BHMT, MAT2b and DNMT3a, as well as increased SAM/SAH concentrations and global DNA hypermethylation. The expression of the total and all the 3 classes of IGF-1 mRNA variants was significantly (P<0.01) down-regulated and IGF-1 concentration was decreased (P<0.05) in the culture media. IGF-1 signaling pathway was also compromised with diminished activation (P<0.05) of STAT3, AKT and mTOR. CpG hypermethylation was detected in the promoter regions of IGF-1 and FOLR1 genes, while higher SLC19A1 mRNA corresponded to hypomethylation of its promoter. IGF-1 supplementation in FD media significantly abolished FD-induced decrease in cell viability. However, IGF-1 had limited effect in rescuing the cell phenotype when added 24h after FD. Taken together, down-regulation of IGF-1 expression and signaling is involved in FD-induced cell cycle arrest and apoptosis in HT-22 hippocampal neuron cells, which is associated with an abnormal activation of methyl transfer pathway and hypermethylation of IGF-1 gene promoter. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Finite mixture clustering of human tissues with different levels of IGF-1 splice variants mRNA transcripts.

    PubMed

    Pelosi, Michele; Alfò, Marco; Martella, Francesca; Pappalardo, Elisa; Musarò, Antonio

    2015-09-15

    This study addresses a recurrent biological problem, that is to define a formal clustering structure for a set of tissues on the basis of the relative abundance of multiple alternatively spliced isoforms mRNAs generated by the same gene. To this aim, we have used a model-based clustering approach, based on a finite mixture of multivariate Gaussian densities. However, given we had more technical replicates from the same tissue for each quantitative measurement, we also employed a finite mixture of linear mixed models, with tissue-specific random effects. A panel of human tissues was analysed through quantitative real-time PCR methods, to quantify the relative amount of mRNA encoding different IGF-1 alternative splicing variants. After an appropriate, preliminary, equalization of the quantitative data, we provided an estimate of the distribution of the observed concentrations for the different IGF-1 mRNA splice variants in the cohort of tissues by employing suitable kernel density estimators. We observed that the analysed IGF-1 mRNA splice variants were characterized by multimodal distributions, which could be interpreted as describing the presence of several sub-population, i.e. potential tissue clusters. In this context, a formal clustering approach based on a finite mixture model (FMM) with Gaussian components is proposed. Due to the presence of potential dependence between the technical replicates (originated by repeated quantitative measurements of the same mRNA splice isoform in the same tissue) we have also employed the finite mixture of linear mixed models (FMLMM), which allowed to take into account this kind of within-tissue dependence. The FMM and the FMLMM provided a convenient yet formal setting for a model-based clustering of the human tissues in sub-populations, characterized by homogeneous values of concentrations of the mRNAs for one or multiple IGF-1 alternative splicing isoforms. The proposed approaches can be applied to any cohort of tissues

  17. Matrix IGF-1 regulates bone mass by activation of mTOR in mesenchymal stem cells

    PubMed Central

    Xian, Lingling; Wu, Xiangwei; Pang, Lijuan; Lou, Michael; Rosen, Clifford; Qiu, Tao; Crane, Janet; Frassica, Frank; Zhang, Liming; Rodriguez, Juan Pablo; Jia, Xiaofeng; Yakar, Shoshana; Xuan, Shouhong; Efstratiadis, Argiris; Wan, Mei; Cao, Xu

    2012-01-01

    Insulin-like growth factor 1 (IGF-1), the most abundant growth factor in the bone matrix, regulates bone mass in adulthood. We report that IGF-1 released from bone matrix stimulates osteoblastic differentiation of mesenchymal stem cell (MSCs) by activation of mTOR during bone remodeling. Mice knockout of IGF-1 receptor (Igf1r) in the preosteoblastic cells exhibited low bone mass and reduced mineral deposition rates. The MSCs recruited to the bone surface were unable to differentiate into osteoblasts. In age-related osteoporosis in humans, we found that marrow IGF-1 levels were 40% lower than controls. Similarly, the levels of IGF-1 in the bone matrix and marrow of aged rats were also decreased and directly correlated with the age-related decrease in bone mass. Notably, injection of IGF-1 with IGF binding protein 3 (IGFBP3), not IGF-1 alone, increased the level of IGF-1 in the bone matrix and stimulated new bone formation in old rats. Thus, IGF-1 released during bone resorption from bone matrix activates mTOR to induce osteoblast differentiation of MSCs in maintaining bone micro-architecture and mass. PMID:22729283

  18. 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.

  19. High fat-diet and saturated fatty acid palmitate inhibits IGF-1 function in chondrocytes.

    PubMed

    Nazli, S A; Loeser, R F; Chubinskaya, S; Willey, J S; Yammani, R R

    2017-09-01

    Insulin-like growth factor-1 (IGF-1) promotes matrix synthesis and cell survival in cartilage. Chondrocytes from aged and osteoarthritic cartilage have a reduced response to IGF-1. The purpose of this study was to determine the effect of free fatty acids (FFA) present in a high-fat diet on IGF-1 function in cartilage and the role of endoplasmic reticulum (ER) stress. C57BL/6 male mice were maintained on either a high-fat (60% kcal from fat) or a low-fat (10% kcal from fat) diet for 4 months. Mice were then sacrificed; femoral head cartilage caps were collected and treated with IGF-1 to measure proteoglycan (PG) synthesis. Cultured human chondrocytes were treated with 500 μM FFA palmitate or oleate, followed by stimulation with (100 ng/ml) IGF-1 overnight to measure CHOP (a protein marker for ER stress) and PG synthesis. Human chondrocytes were pre-treated with palmitate or 1 mM 4-phenyl butyric acid (PBA) or 1 μM C-Jun N terminal Kinase (JNK) inhibitor, and IGF-1 function (PG synthesis and signaling) was measured. Cartilage explants from mice on the high fat-diet showed reduced IGF-1 mediated PG synthesis compared to a low-fat group. Treatment of human chondrocytes with palmitate induced expression of CHOP, activated JNK and inhibited IGF-1 function. PBA, a small molecule chemical chaperone that alleviates ER stress rescued IGF-1 function and a JNK inhibitor rescued IGF-1 signaling. Palmitate-induced ER stress inhibited IGF-1 function in chondrocytes/cartilage via activating the mitogen-activated protein (MAP) kinase JNK. This is the first study to demonstrate that ER stress is metabolic factor that regulates IGF-1 function in chondrocytes. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  20. Northwestern profiling of potential translation-regulatory proteins in human breast epithelial cells and malignant breast tissues: evidence for pathological activation of the IGF1R IRES.

    PubMed

    Blume, Scott W; Jackson, Nateka L; Frost, Andra R; Grizzle, William E; Shcherbakov, Oleg D; Choi, Hyoungsoo; Meng, Zheng

    2010-06-01

    Genes involved in the control of cell proliferation and survival (those genes most important to cancer pathogenesis) are often specifically regulated at the translational level, through RNA-protein interactions involving the 5'-untranslated region of the mRNA. IGF1R is a proto-oncogene strongly implicated in human breast cancer, promoting survival and proliferation of tumor cells, as well as metastasis and chemoresistance. Our lab has focused on the molecular mechanisms regulating IGF1R expression at the translational level. We previously discovered an internal ribosome entry site (IRES) within the 5'-untranslated region of the human IGF1R mRNA, and identified and functionally characterized two individual RNA-binding proteins, HuR and hnRNP C, which bind the IGF1R 5'-UTR and differentially regulate IRES activity. Here we have developed and implemented a high-resolution northwestern profiling strategy to characterize, as a group, the full spectrum of sequence-specific RNA-binding proteins potentially regulating IGF1R translational efficiency through interaction with the 5'-untranslated sequence. The putative IGF1R IRES trans-activating factors (ITAFs) are a heterogeneous group of RNA-binding proteins including hnRNPs originating in the nucleus as well as factors tightly associated with ribosomes in the cytoplasm. The IGF1R ITAFs can be categorized into three distinct groups: (a) high molecular weight external ITAFs, which likely modulate the overall conformation of the 5'-untranslated region of the IGF1R mRNA and thereby the accessibility of the core functional IRES; (b) low molecular weight external ITAFs, which may function as general chaperones to unwind the RNA, and (c) internal ITAFs which may directly facilitate or inhibit the fundamental process of ribosome recruitment to the IRES. We observe dramatic changes in the northwestern profile of non-malignant breast cells downregulating IGF1R expression in association with acinar differentiation in 3-D culture

  1. IGF-1 protects oligodendrocyte progenitors against TNFalpha-induced damage by activation of PI3K/Akt and interruption of the mitochondrial apoptotic pathway.

    PubMed

    Pang, Yi; Zheng, Baoying; Fan, Lir-Wan; Rhodes, Philip G; Cai, Zhengwei

    2007-08-15

    Proinflammatory cytokine-mediated injury to oligodendrocyte progenitor cells (OPCs) has been proposed as a cause of periventricular leukomalacia (PVL), the most common brain injury found in preterm infants. Preventing death of OPCs is a potential strategy to prevent or treat PVL. In the current study, we utilized an in vitro cell culture system to investigate the effect of insulin-like growth factor-1 (IGF-1) on tumor necrosis factor-alpha (TNFalpha)-induced OPC injury and the possible mechanisms involved. OPCs were isolated from neonatal rat optic nerves and cultured in chemically defined medium (CDM) supplemented with platelet-derived growth factor and basic fibroblast growth factor. Exposure to TNFalpha resulted in death of OPCs. IGF-1 protected OPCs from TNFalpha cytotoxicity in a dose-dependent manner as measured by the XTT and TUNEL assays. IGF-1 activates both the PI3K/Akt and the extracellular signal-regulated kinase (ERK) pathway. However, IGF-1-enhanced cell survival signals were mediated by the PI3K/Akt, but not by the ERK pathway, as evidenced by the observation that IGF-1-enhanced cell survival was partially abrogated by Akti, the Akt inhibitor, or wortmannin, the PI3K inhibitor, but not by PD98,059, the MAPK kinase/ERK kinase inhibitor. The downstream events of IGF-1-triggered survival signals included phosphorylation of BAD, blockade of TNFalpha-induced translocation of Bax from the cytosol to the mitochondrial membrane, and suppression of caspase-9 and caspase-3 activation. These observations indicate that the protection of OPCs by IGF-1 is mediated, at least partially, by interruption of the mitochondrial apoptotic pathway via activation of PI3K/Akt.

  2. Reorganization of motor cortex and impairment of motor performance induced by hindlimb unloading are partially reversed by cortical IGF-1 administration.

    PubMed

    Mysoet, Julien; Canu, Marie-Hélène; Gillet, Christophe; Fourneau, Julie; Garnier, Cyril; Bastide, Bruno; Dupont, Erwan

    2017-01-15

    Immobilization, bed rest, or sedentary lifestyle, are known to induce a profound impairment in sensorimotor performance. These alterations are due to a combination of peripheral and central factors. Previous data conducted on a rat model of disuse (hindlimb unloading, HU) have shown a profound reorganization of motor cortex and an impairment of motor performance. Recently, our interest was turned towards the role of insulin-like growth factor 1 (IGF-1) in cerebral plasticity since this growth factor is considered as the mediator of beneficial effects of exercise on the central nervous system, and its cortical level is decreased after a 14-day period of HU. In the present study, we attempted to determine whether a chronic subdural administration of IGF-1 in HU rats could prevent deleterious effects of HU on the motor cortex and on motor activity. We demonstrated that HU induces a shrinkage of hindlimb cortical representation and an increase in current threshold to elicit a movement. Administration of IGF-1 in HU rats partially reversed these changes. The functional evaluation revealed that IGF-1 prevents the decrease in spontaneous activity found in HU rats and the changes in hip kinematics during overground locomotion, but had no effect of challenged locomotion (ladder rung walking test). Taken together, these data clearly indicate the implication of IGF-1 in cortical plastic mechanisms and in behavioral alteration induced by a decreased in sensorimotor activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. 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

  4. Epitope-specific mechanisms of IGF1R inhibition by ganitumab.

    PubMed

    Calzone, Frank J; Cajulis, Elaina; Chung, Young-Ah; Tsai, Mei-Mei; Mitchell, Petia; Lu, John; Chen, Ching; Sun, Jilin; Radinsky, Robert; Kendall, Richard; Beltran, Pedro J

    2013-01-01

    Therapeutic antibodies targeting the IGF1R have shown diverse efficacy and safety signals in oncology clinical trials. The success of these agents as future human therapeutics depends on understanding the specific mechanisms by which these antibodies target IGF1R signaling. A panel of well-characterized assays was used to investigate the mechanisms by which ganitumab, a fully human anti-IGF1R antibody undergoing clinical testing, inhibits IGF1R activity. Epitope mapping using IGF1R subdomains localized the ganitumab binding site to the L2 domain. Binding of ganitumab inhibited the high-affinity interaction of IGF-1 and IGF-2 required to activate IGF1R in cells engineered for IGF1R hypersensitivity and in human cancer cell lines, resulting in complete blockade of ligand-induced cellular proliferation. Inhibition of IGF1R activity by ganitumab did not depend on endosomal sequestration, since efficient ligand blockade was obtained without evidence of receptor internalization and degradation. Clinically relevant concentrations of ganitumab also inhibited the activation of hybrid receptors by IGF-1 and IGF-2. Ganitumab was not an agonist of homodimeric IGF1R or hybrid receptors in MCF-7 and COLO 205 cells, but low-level IGF1R activation was detected in cells engineered for IGF1R hypersensitivity. This activation seems biologically irrelevant since ganitumab completely inhibited ligand-driven proliferation. The in vivo efficacy profile of ganitumab was equivalent or better than CR and FnIII-1 domain-specific antibodies, alone or in combination with irinotecan. CR domain-specific antibodies only blocked IGF-1 binding to IGF1R but were more potent than ganitumab at inducing homodimer and hybrid receptor downregulation in vitro, however this difference was less obvious in vivo. No inhibition of hybrid receptors was observed with the FnIII-1 domain antibodies, which were relatively strong homodimer and hybrid agonists. The safety and efficacy profile of ganitumab and other

  5. 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

  6. Evaluation of a Novel Hexavalent Humanized Anti-IGF-1R Antibody and Its Bivalent Parental IgG in Diverse Cancer Cell Lines

    PubMed Central

    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. PMID:22952934

  7. 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.

  8. 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.

  9. 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.

  10. Inhibiting IGF-1R attenuates cell proliferation and VEGF production in IGF-1R over-expressing EGFR mutant non-small cell lung cancer cells.

    PubMed

    Yeo, Chang Dong; Kim, Young Ae; Lee, Hwa Young; Kim, Jin Woo; Lee, Sang Haak; Kim, Seung Joon; Kwon, Soon Seog; Kim, Yong Hyun; Kim, Seok Chan

    2017-02-01

    The aim of the present study was to demonstrate the role of insulin-like growth factor-1 receptor (IGF-1R) tyrosine kinase inhibitors (TKIs) in IGF-1R expressed epidermal growth factor receptor (EGFR) mutant cells. Human lung adenocarcinoma PC9, HCC827, and H1975 cells were exposed to a combination of IGF-1, gefitinib, or linsitinib. Cell viability was assessed by the MTT assay. The expression of EGFR, IGF-1R, AKT, extracellular regulated kinases 1 and 2 (ERK1/2), cleaved poly ADP ribose polymerase (PARP), cleaved caspase 3, and hypoxia-inducible factor (HIF)-1α were measured by Western blot. The concentrations of vascular endothelial growth factor (VEGF) were measured using an enzyme-linked immunosorbent assay kit. Cell growth in PC9 and HCC827 cells was synergistically suppressed by co-treatment with gefitinib and linsitinib. Gefitinib did not affect H1975 cell growth; however, linsitinib suppressed cell proliferation. Co-treatment with gefitinib and linsitinib inhibited pAKT and pERK, and linsitinib treatment profoundly reduced IGF-1-induced pIGF-1R expression in PC9 and HCC827 cells. Dual treatment increased the number of Annexin-V-positive HCC827 and H1975 cells, and expression of cleaved caspase 3 and cleaved PARP increased in H1975 cells following linsitinib treatment. Gefitinib inhibited HIF-1α and VEGF expression in HCC827 cells, and linsitinib inhibited VEGF production in H1975 cells. IGF-1R TKIs had modest anti-tumor efficacy and their effects were explained by blocking the EGFR and IGF-1R pathway in IGF-1R expressing EGFR-sensitive cells. IGF-1R TKI had pro-apoptotic activity and inhibited cellular growth in EGFR-resistant cells.

  11. Elucidating the role of the FoxO3a transcription factor in the IGF-1-induced migration and invasion of uveal melanoma cancer cells.

    PubMed

    Yan, Fengxia; Liao, Rifang; Farhan, Mohd; Wang, Tinghuai; Chen, Jiashu; Wang, Zhong; Little, Peter J; Zheng, Wenhua

    2016-12-01

    Uveal melanoma (UM) is the most common primary intraocular malignant tumor of adults. It has high mortality rate due to liver metastasis. However, the epidemiology and pathogenesis of liver metastasis in UM are not elucidated and there is no effective therapy available for preventing the development of this disease. IGF-1 is a growth factor involved in cell proliferation, malignant transformation and inhibition of apoptosis. In previous report, IGF-1 receptor was found to be highly expressed in UM and this was related to tumor prognosis. FoxO3a is a Forkhead box O (FOXO) transcription factor and a downstream target of the IGF-1R/PI3K/Akt pathway involved in a number of physiological and pathological processes including cancer. However, the role of FoxO3a in UM is unknown. In the present study, we investigated fundamental mechanisms in the growth, migration and invasion of UM and the involvement of FoxO3a. IGF-1 increased the cell viability, invasion, migration and S-G2/M cell cycle phase accumulation of UM cells. Western blot analysis showed that IGF-1 led to activation of Akt and concomitant phosphorylation of FoxO3a. FoxO3a phosphorylation was associated with its translocation into the cytoplasm from the nucleus and its functional inhibition led to the inhibition of expression of Bim and p27, but an increase in the expression of Cyclin D1. The effects of IGF-1 on UM cells were reversed by LY294002 (a PI3K inhibitor) or Akt siRNA, and the overexpression of FoxO3a also attenuated basal invasion and migration of UM. Taken all together, these results suggest that inhibition of FoxO3a by IGF-1 via the PI3K/Akt pathway has an important role in IGF-1 induced proliferation and invasion of UM cells. These findings also support FoxO3a and IGF signaling may represent a valid target for investigating the development of new strategies for the treatment and prevention of the pathology of UM. Copyright © 2016. Published by Elsevier Masson SAS.

  12. Targeted DNA methylation screen in the mouse mammary genome reveals a parity-induced hypermethylation of IGF1R which persists long after parturition

    PubMed Central

    Katz, Tiffany A.; Liao, Serena G.; Palmieri, Vincent J.; Dearth, Robert K.; Pathiraja, Thushangi N.; Huo, Zhiguang; Shaw, Patricia; Small, Sarah; Davidson, Nancy E.; Peters, David G.; Tseng, George C.; Oesterreich, Steffi; Lee, Adrian V.

    2015-01-01

    The most effective natural prevention against breast cancer is an early first full term pregnancy. Understanding how the protective effect is elicited will inform the development of new prevention strategies. To better understand the role of epigenetics in long-term protection, we investigated parity-induced DNA methylation in the mammary gland. FVB mice were bred or remained nulliparous and mammary glands harvested immediately after involution (early), or 6 months following involution (late), allowing identification of both transient and persistent changes. Targeted DNA methylation (109 Mb of Ensemble regulatory features) analysis was performed using the SureSelectXT Mouse Methy-seq assay and massively parallel sequencing. 269 genes were hypermethylated and 128 hypomethylated persistently at both the early and late time points. Pathway analysis of the persistently differentially methylated genes revealed Igf1r to be central to one of the top identified signaling networks, and Igf1r itself was one of the most significantly hypermethylated genes. Hypermethylation of Igf1r in the parous mammary gland was associated with a reduction of Igf1r mRNA expression. These data suggest that the IGF pathway is regulated at multiple levels during pregnancy, and that its modification might be critical in the protective role of pregnancy. This supports the approach of lowering IGF action for prevention of breast cancer, a concept which is currently being tested clinically. PMID:26290394

  13. 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

  14. 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.

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

    PubMed Central

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

    2016-01-01

    ABSTRACT 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 7th and 20th 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. PMID:27326759

  16. 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.

  17. 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.

  18. Role of trophic factors GDNF, IGF-1 and VEGF in major depressive disorder: A comprehensive review of human studies

    PubMed Central

    Sharma, Ajaykumar N.; da Costa e Silva, Bruno Fernando Borges; Soares, Jair C.; Carvalho, André F.; Quevedo, Joao

    2016-01-01

    Rationale The neurotrophin hypothesis of major depressive disorder (MDD) postulates that this illness results from aberrant neurogenesis in brain regions that regulates emotion and memory. Notwithstanding this theory has primarily implicated BDNF in the neurobiology of MDD. Recent evidence suggests that other trophic factors namely GDNF, VEGF and IGF-1 may also be involved. Purpose The present review aimed to critically summarize evidence regarding changes in GDNF, IGF-1 and VEGF in individuals with MDD compared to healthy controls. In addition, we also evaluated the role of these mediators as potential treatment response biomarkers for MDD. Methods A comprehensive review of original studies studies measuring peripheral, central or mRNA levels of GDNF, IGF-1 or VEGF in patients with MDD was conducted. The PubMed/MEDLINE database was searched for peer-reviewed studies published in English through June 2nd, 2015. Results Most studies reported a reduction in peripheral GDNF and its mRNA levels in MDD patients versus controls. In contrast, IGF-1 levels in MDD patients compared to controls were discrepant across studies. Finally, most studies reported high peripheral VEGF levels and mRNA expression in MDD patients compared to healthy controls. Conclusions GDNF, IGF-1 and VEGF levels and their mRNA expression appear to be differentially altered in MDD patients compared to healthy individuals, indicating that these molecules might play an important role in the pathophysiology of depression and antidepressant action of therapeutic interventions. PMID:26956384

  19. 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

  20. Palmitate-induced ER stress and subsequent C 1 HOP activation attenuates leptin and IGF1expression in the brain

    USDA-ARS?s Scientific Manuscript database

    Background: The peptide hormones insulin-like growth factor-1 (IGF1) and leptin mediate a myriad of biological effects both in the peripheral and central nervous systems. The transcription of these two hormones is regulated by the transcription factor C/EBPa, which in turn is negatively regulated by...

  1. IGF-1-dependent subunit communication of the IGF-1 holoreceptor: Interactions between. alpha. beta. heterodimeric receptor halves

    SciTech Connect

    Wilden, P.A.; Treadway, J.L.; Morrison, B.D.; Pessin, J.E. )

    1989-12-12

    Examination of {sup 125}I-IGF-1 affinity cross-linking and {beta}-subunit autophosphorylation has indicated that IGF-1 induces a covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptors into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state, in a similar manner to that observed for the insulin receptor. The formation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 receptor complex from the partially purified {alpha}{beta} heterodimers was time dependent with half-maximal formation in approximately 30 min at saturating IGF-1 concentrations. The IGF-1-dependent association of the partially purified {alpha}{beta} heterodimers into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state was specific for the IGF-1 receptors since IGF-1 was unable to stimulate the protein kinase activity of the purified {alpha}{beta} heterodimeric insulin receptor complex. Incubation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 holoreceptor with the specific sulfhydryl agent iodoacetamide (IAN) did not alter {sup 125}I-IGF-1 binding or IGF-1 stimulation of protein kinase activity. However, IAN treatment of the {alpha}{beta} heterodimeric IGF-1 receptors inhibited the IGF-1 dependent covalent formation of the disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric complex. These data indicate that IGF-1 induces the covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptor complexes into a disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric state whereas Mn/MgATP induces a noncovalent association. Therefore, unlike the insulin receptor in which noncovalent association is sufficient for kinase activation, only the covalent assembly of the IGF-1 receptor {alpha}{beta} heterodimers into the {alpha}{sub 2}{beta}{sub 2} heterotetrameric holoreceptor complex is associated with ligand-stimulated protein kinase activation.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Differential Role of Rapamycin in Epidermis-Induced IL-15-IGF-1 Secretion via Activation of Akt/mTORC2.

    PubMed

    Bai, Yang; Xu, Rui; Zhang, Xueyuan; Zhang, Xiaorong; Hu, Xiaohong; Li, Yashu; Li, Haisheng; Liu, Meixi; Huang, Zhenggen; Yan, Rongshuai; He, Weifeng; Luo, Gaoxing; Wu, Jun

    2017-07-26

    Backgroud/Aims: The effects of rapamycin (RPM) on wound healing have been previously studied. However, reciprocal contradictory data have been reported, and the underlying mechanism remains unclear. This study aims to uncover differential role of RPM in regulation of wound healing and explore the possible mechanism. C57BL/6J mice and epidermal cells were treated with different doses of RPM. The wound re-epithelialization was observed by hematoxylin and eosin (HE) staining. The expression of IL-15 and IGF-1 were detected by immunohistochemistry and quantitative real-time PCR. Epidermal cell survival was determined by CCK-8 assays. Moreover, the mTORC1 and mTORC2 pathway were examined by western blot analysis. This study showed that differential doses of RPM could lead to separate consequences in epidermis. Histological analyses showed that low-dose RPM promoted wound healing, and enhanced the expression of IL-15 and IGF-1. Furthermore, western blot analysis showed that the effect of low-dose RPM in epidermis were not through mTORC1 pathway. Instead, activation of the Akt/mTORC2 pathway was involved in low-dose RPM-induced IL-15 and IGF-1 production in epidermis, while high-dose RPM inhibited the expression of IL-15 and IGF-1 and the activity of mTORC1 and mTORC2 pathway. This study for the first time demonstrated that RPM-mediated wound healing was dose-dependent. © 2017 The Author(s). Published by S. Karger AG, Basel.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. IGF-1 receptor inhibition by picropodophyllin in medulloblastoma

    SciTech Connect

    Ohshima-Hosoyama, Sachiko; Hosoyama, Tohru; Nelon, Laura D.; Keller, Charles

    2010-09-03

    Research highlights: {yields} Igf1r is overexpressed and activated in a Sonic Hedgehog driven model of medulloblastoma. {yields} Picropodophyllin targets and abrogates IGF signaling in medulloblastoma. {yields} Picropodophyllin inhibits medulloblastoma tumor cell growth by induction of apoptosis. -- Abstract: The insulin-like growth factor-1 receptor (Igf1r) is a multifunctional membrane-associated tyrosine kinase associated with regulation of transformation, proliferation, differentiation and apoptosis. Increased IGF pathway activity has been reported in human and murine medulloblastoma. Tumors from our genetically-engineered medulloblastoma mouse model over-express Igf1r, and thus this mouse model is a good platform with which to study the role of Igf1r in tumor progression. We hypothesize that inhibition of IGF pathway in medulloblastoma can slow or inhibit tumor growth and metastasis. To test our hypothesis, we tested the role of IGF in tumor growth in vitro by treatment with the tyrosine kinase small molecule inhibitor, picropodophyllin (PPP), which strongly inhibits the IGF pathway. Our results demonstrate that PPP-mediated downregulation of the IGF pathway inhibits mouse tumor cell growth and induces apoptotic cell death in vitro in primary medulloblastoma cultures that are most reflective of tumor cell behavior in vivo.

  14. 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

  15. IgA Enhances IGF-1 Mitogenic Activity Via Receptor Modulation in Glomerular Mesangial Cells: Implications for IgA-Induced Nephropathy.

    PubMed

    Al-Eisa, Amal; Dhaunsi, Gursev S

    2017-06-27

    Glomerulonephritis due to mesangial proliferation is responsible for renal dysfunction in IgA nephropathy (IgAN), however molecular mechanisms of pathogenesis are not well known. We examined the effect of IgA on Insulin-like Growth Factor-1 (IGF-1) activity, a potent mitogen with vital role in growth and development of children, and IGF-1 receptor (IGF-1R) in cultures of glomerular mesangial cells (GMC). GMC were isolated from rat kidneys using sieving and enzymatic digestion of tissue homogenates, and cultured in RPMI 1640 medium. GMC cultures were treated with IgA (0-10 µg/ml) in the presence or absence of IGF-1 and fetal bovine serum (FBS), and BrdU incorporation was measured. IGF-1 levels were assayed along with real-time PCR quantification of IGF-1R mRNA. Treatment of GMC with IgA (5 -10 µg/ml) significantly (p < 0.01) increased the BrdU incorporation in the presence or absence of FBS or IGF-1. IgA-mediated effects were more pronounced in IGF-1 treated cells that were significantly (p < 0.01) blocked by pretreatment of cells with IGF-1 receptor antibody or genistein. IgA significantly increased the levels of IGF-1 in culture supernatants and GMC homogenates. IGF-1R mRNA was significantly (p < 0.01) increased in IgA treated cells particularly by co-treatment with IGF-1. These findings show that IgA enhances the IGF-1 activity in GMC via stimulation of IGF-1R gene transcription and suggest a role for IGF-1 in pathogenesis of IgAN. © 2017 The Author(s). Published by S. Karger AG, Basel.

  16. GIPC mediates the generation of reactive oxygen species and the regulation of cancer cell proliferation by insulin-like growth factor-1/IGF-1R signaling.

    PubMed

    Choi, Ji Seung; Paek, A Rome; Kim, Soo Youl; You, Hye Jin

    2010-08-28

    Insulin-like growth factor-1 (IGF-1)/IGF-1 receptor signaling participates in a variety of cellular processes, including cell survival, growth, and proliferation. Increased expression of IGF-1R and activation of its downstream signaling components have been implicated in human cancers. Although a regulatory role for IGF-1R has been established, the relationship between IGF-1R and its binding partner, GAIP-interacting protein C-terminus (GIPC), in terms of promoting cell proliferation, remains unclear. We found that siRNA-mediated silencing of GIPC expression decreased IGF-1-mediated IGF-1R phosphorylation and cellular proliferation in breast cancer models. IGF-1-mediated cellular proliferation was also inhibited by N-acetylcysteine, which implicates reactive oxygen species generation. siRNA-mediated silencing of GIPC expression also decreased IGF-1-mediated reactive oxygen species generation. Taken together, these data suggest that GIPC contributes to IGF-1-induced cancer cell proliferation via the regulation of reactive oxygen species production. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Activation of IGF1 Signaling in the Cochlea Induces the Transcription of Its Mediators During the Protection of Cochlear Hair Cells Against Aminoglycoside.

    PubMed

    Hayashi, Yushi; Yamamoto, Norio; Nakagawa, Takayuki; Omori, Koichi; Ito, Juichi

    2017-02-01

    Transcription of the Erk and Akt genes and phosphorylation of their products are promoted by insulin-like growth factor 1 (IGF1) during hair cell protection. IGF1 protects mammalian hair cells in animal models from various types of damage, including aminoglycoside. Moreover, clinical trials have revealed that IGF1 was effective for idiopathic sudden sensorineural hearing loss. In this process, activation of the downstream of IGF1 signaling, including the phosphorylation of extracellular signal-regulated kinase (ERK) and AKT proteins, is involved. However, the regulation of IGF1 signaling mediators at the transcriptional level has not been studied. We used a neomycin damage model on neonatal mouse cochlear explant culture. Explants established from neonatal mice were treated with either neomycin alone or neomycin and IGF1. The expression levels of IGF1 signaling mediator genes, Akt1, Mapk3, and Mapk1, in the explants were compared using quantitative reverse transcriptase-polymerase chain reaction at several time points. Inhibitors of IGF1 signaling were added to confirm that this observation was dependent on IGF1 signaling. The expression levels of all genes tested were significantly upregulated in neomycin+IGF1 treatment samples (p < 0.0001, analysis of variance [ANOVA]). Addition of inhibitors of IGF1 signaling significantly attenuated the upregulation of expression (p < 0.0001, ANOVA). IGF1 treatment upregulates the expression of its mediator genes during the protection of hair cells against aminoglycoside. The regulation of mediator gene expression may serve as a novel treatment for sensorineural hearing loss.

  3. Regular voluntary exercise cures stress-induced impairment of cognitive function and cell proliferation accompanied by increases in cerebral IGF-1 and GST activity in mice.

    PubMed

    Nakajima, Sanae; Ohsawa, Ikuroh; Ohta, Shigeo; Ohno, Makoto; Mikami, Toshio

    2010-08-25

    Chronic stress impairs cognitive function and hippocampal neurogenesis. This impairment is attributed to increases in oxidative stress, which result in the accumulation of lipid peroxide. On the other hand, voluntary exercise enhances cognitive function, hippocampal neurogenesis, and antioxidant capacity in normal animals. However, the effects of voluntary exercise on cognitive function, neurogenesis, and antioxidants in stressed mice are unclear. This study was designed to investigate whether voluntary exercise cures stress-induced impairment of cognitive function accompanied by improvement of hippocampal neurogenesis and increases in antioxidant capacity. Stressed mice were exposed to chronic restraint stress (CRS), which consisted of 12h immobilization daily and feeding in a small cage, for 8 weeks. Exercised mice were allowed free access to a running wheel during their exposure to CRS. At the 6th week, cognitive function was examined using the Morris water maze (MWM) test. Daily voluntary exercise restored stress-induced impairment of cognitive function and the hippocampal cell proliferation of newborn cells but not cell survival. Voluntary exercise increased insulin-like growth factor 1 (IGF-1) protein and mRNA expression in the cerebral cortex and liver, respectively. In addition, CRS resulted in a significant increase in the number of 4-hydrosynonenal (4-HNE)-positive cells in the hippocampal dentate gyrus; whereas, voluntary exercise inhibited it and enhanced glutathione s-transferases (GST) activity in the brain. These findings suggest that voluntary exercise attenuated the stress-induced impairment of cognitive function accompanied by improvement of cell proliferation in the dentate gyrus. This exercise-induced improvement was attributed to exercise-induced enhancement of IGF-1 protein and GST activity in the brain. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Treatment with Insulin Analog X10 and IGF-1 Increases Growth of Colon Cancer Allografts

    PubMed Central

    Hvid, Henning; Blouin, Marie-José; Birman, Elena; Damgaard, Jesper; Poulsen, Fritz; Fels, Johannes Josef; Fledelius, Christian; Hansen, Bo Falck; Pollak, Michael

    2013-01-01

    Obesity and type 2 diabetes are associated with an increased risk for development of certain forms of cancer, including colon cancer. The publication of highly controversial epidemiological studies in 2009 raised the possibility that use of the insulin analog glargine increases this risk further. However, it is not clear how mitogenic effects of insulin and insulin analogs measured in vitro correlate with tumor growth-promoting effects in vivo. The aim of this study was to examine possible growth-promoting effects of native human insulin, insulin X10 and IGF-1, which are considered positive controls in vitro, in a short-term animal model of an obesity- and diabetes-relevant cancer. We characterized insulin and IGF-1 receptor expression and the response to treatment with insulin, X10 and IGF-1 in the murine colon cancer cell line (MC38 cells) in vitro and in vivo. Furthermore, we examined pharmacokinetics and pharmacodynamics and monitored growth of MC38 cell allografts in mice with diet-induced obesity treated with human insulin, X10 and IGF-1. Treatment with X10 and IGF-1 significantly increased growth of MC38 cell allografts in mice with diet-induced obesity and we can therefore conclude that supra-pharmacological doses of the insulin analog X10, which is super-mitogenic in vitro and increased the incidence of mammary tumors in female rats in a 12-month toxicity study, also increase growth of tumor allografts in a short-term animal model. PMID:24260289

  5. 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

  6. Human Longevity and Variation in GH/IGF-1/Insulin Signaling, DNA Damage Signaling and Repair and Pro/antioxidant Pathway Genes: Cross Sectional and Longitudinal Studies

    PubMed Central

    Soerensen, Mette; Dato, Serena; Tan, Qihua; Thinggaard, Mikael; Kleindorp, Rabea; Beekman, Marian; Jacobsen, Rune; Suchiman, H. Eka D.; de Craen, Anton J.M.; Westendorp, Rudi G.J.; Schreiber, Stefan; Stevnsner, Tinna; Bohr, Vilhelm A.; Slagboom, P. Eline; Nebel, Almut; Vaupel, James W.; Christensen, Kaare; McGue, Matt; Christiansen, Lene

    2012-01-01

    Here we explore association with human longevity of common genetic variation in three major candidate pathways: GH/IGF-1/insulin signaling, DNA damage signaling and repair and pro/antioxidants by investigating 1273 tagging SNPs in 148 genes composing these pathways. In a case-control study of 1089 oldest-old (age 92–93) and 736 middle-aged Danes we found 1 pro/antioxidant SNP (rs1002149 (GSR)), 5 GH/IGF-1/INS SNPs (rs1207362 (KL), rs2267723 (GHRHR), rs3842755 (INS), rs572169 (GHSR), rs9456497 (IGF2R)) and 5 DNA repair SNPs (rs11571461 (RAD52), rs13251813 (WRN), rs1805329 (RAD23B), rs2953983 (POLB), rs3211994 (NTLH1)) to be associated with longevity after correction for multiple testing. In a longitudinal study with 11 years of follow-up on survival in the oldest-old Danes we found 2 pro/antioxidant SNPs (rs10047589 (TNXRD1), rs207444 (XDH)), 1 GH/IGF-1/INS SNP (rs26802 (GHRL)) and 3 DNA repair SNPs (rs13320360 (MLH1), rs2509049 (H2AFX) and rs705649 (XRCC5)) to be associated with mortality in late life after correction for multiple testing. When examining the 11 SNPs from the case-control study in the longitudinal data, rs3842755 (INS), rs13251813 (WRN) and rs3211994 (NTHL1) demonstrated the same directions of effect (p<0.05), while rs9456497 (IGF2R) and rs1157146 (RAD52) showed non-significant tendencies, indicative of effects also in late life survival. In addition, rs207444 (XDH) presented the same direction of effect when inspecting the 6 SNPs from the longitudinal study in the case-control data, hence, suggesting an effect also in survival from middle age to old age. No formal replications were observed when investigating the 11 SNPs from the case-control study in 1613 oldest-old (age 95–110) and 1104 middle-aged Germans, although rs11571461 (RAD52) did show a supportive non-significant tendency (OR = 1.162, 95% CI = 0.927–1.457). The same was true for rs10047589 (TNXRD1) (HR = 0.758, 95%CI = 0.543–1.058) when examining the 6 SNPs from the longitudinal

  7. An Integrin Binding-defective Mutant of Insulin-like Growth Factor-1 (R36E/R37E IGF1) Acts as a Dominant-negative Antagonist of the IGF1 Receptor (IGF1R) and Suppresses Tumorigenesis but Still Binds to IGF1R*

    PubMed Central

    Fujita, Masaaki; Ieguchi, Katsuaki; Cedano-Prieto, Dora M.; Fong, Andrew; Wilkerson, Charles; Chen, Jane Q.; Wu, Mac; Lo, Su-Hao; Cheung, Anthony T. W.; Wilson, Machelle D.; Cardiff, Robert D.; Borowsky, Alexander D.; Takada, Yoko K.; Takada, Yoshikazu

    2013-01-01

    Insulin-like growth factor-1 (IGF1) is a major therapeutic target for cancer. We recently reported that IGF1 directly binds to integrins (αvβ3 and α6β4) and induces ternary complex formation (integrin-IGF1-IGF1 receptor (IGF1R)) and that the integrin binding-defective mutant of IGF1 (R36E/R37E) is defective in signaling and ternary complex formation. These findings predict that R36E/R37E competes with WT IGF1 for binding to IGF1R and inhibits IGF signaling. Here, we described that excess R36E/R37E suppressed cell viability increased by WT IGF1 in vitro in non-transformed cells. We studied the effect of R36E/R37E on viability and tumorigenesis in cancer cell lines. We did not detect an effect of WT IGF1 or R36E/R37E in cancer cells under anchorage-dependent conditions. However, under anchorage-independent conditions, WT IGF1 enhanced cell viability and induced signals, whereas R36E/R37E did not. Notably, excess R36E/R37E suppressed cell viability and signaling induced by WT IGF1 under anchorage-independent conditions. Using cancer cells stably expressing WT IGF1 or R36E/R37E, we determined that R36E/R37E suppressed tumorigenesis in vivo, whereas WT IGF1 markedly enhanced it. R36E/R37E suppressed the binding of WT IGF1 to the cell surface and the subsequent ternary complex formation induced by WT IGF1. R36E/R37E suppressed activation of IGF1R by insulin. WT IGF1, but not R36E/R37E, induced ternary complex formation with the IGF1R/insulin receptor hybrid. These findings suggest that 1) IGF1 induces signals under anchorage-independent conditions and that 2) R36E/R37E acts as a dominant-negative inhibitor of IGF1R (IGF1 decoy). Our results are consistent with a model in which ternary complex formation is critical for IGF signaling. PMID:23696648

  8. Inhibitory effect of transforming growth factor-. beta. (TGF-. beta. ) on insulin-like growth factor 1 (IGF-1)-induced proliferation and differentiation in primary cultures of pig preadipocytes

    SciTech Connect

    Richardson, R.L.; Hausman, G.J.; Gaskins, H.R. )

    1990-02-26

    The influence of serum, IGF-1 and TGF-{beta} on the differentiation of preadipocytes was examined in primary cultures of porcine adipose tissue cells. In serum-supplemented or serum-free, IGF-1 (1 and 10 nM) had no effect on total cell number. However, IGF-1 (10nM) increased adipocyte number only in serum-supplemented (1% pig serum) cultures, whereas TGF-{beta} (15 pm) reduced the adipocyte number in the presence and absence of IGF-1. Replication of preadipocytes was analyzed with a ({sup 3}H) thymidine assay. Preadipocyte proliferation (cpm in adipocyte fraction) was increased by IGF-1 (10nM) only in cultures containing pig serum. TGF-{beta} had no effect on preadipocyte proliferation specifically, but slightly increased total ({sup 3}H) thymidine incorporation in cultures with serum. Glycerol phosphate dehydrogenase (GPDH) specific activity was decreased by adding TGF-{beta} to serum-free cultures but TGF-{beta} had little effect in serum-supplemented cultures. Cellular secretion of IGF-1 was decreased when TGF-{beta} was added to serum-free or serum-supplemented cultures. These studies indicate that TGF-{beta} does not inhibit adipocyte development in the initial growth phase, but may inhibit differentiation and/or hypertrophy at a later stage of development.

  9. 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.

  10. 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.

  11. 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.

  12. IGF1 regulates RUNX1 expression via IRS1/2: Implications for antler chondrocyte differentiation.

    PubMed

    Yang, Zhan-Qing; Zhang, Hong-Liang; Duan, Cui-Cui; Geng, Shuang; Wang, Kai; Yu, Hai-Fan; Yue, Zhan-Peng; Guo, Bin

    2017-03-19

    Although IGF1 is important for the proliferation and differentiation of chondrocytes, its underlying molecular mechanism is still unknown. Here we addressed the physiologic function of IGF1 in antler cartilage and explored the interplay of IGF1, IRS1/2 and RUNX1 in chondrocyte differentiation. The results showed that IGF1 was highly expressed in antler chondrocytes. Exogenous rIGF1 could increase the proliferation of chondrocytes and cell proportion in the S phase, whereas IGF1R inhibitor PQ401 abrogated the induction by rIGF1. Simultaneously, IGF1 could stimulate the expression of IHH which was a well-known marker for prehypertrophic chondrocytes. Further analysis evidenced that IGF1 regulated the expression of IRS1/2 whose silencing resulted in a rise of IHH mRNA levels, but the regulation was impeded by PQ401. Knockdown of IRS1 or IRS2 with specific siRNA could greatly enhance rIGF1-induced chondrocyte differentiation and reduce the expression of RUNX1. Extraneous rRUNX1 might rescue the effects of IRS1 or IRS2 siRNA on the differentiation. In antler chondrocytes, IGF1 played a role in modulating the expression of RUNX1 through IGF1R. Moreover, attenuation of RUNX1 expression advanced the differentiation elicited by rIGF1, while administration of rRUNX1 to chondrocytes treated with IGF1 siRNA or PQ401 reduced their differentiation. Additionally, siRNA-mediated downregulation of IRS1 or IRS2 in the chondrocytes impaired the interaction between IGF1 and RUNX1. Collectively, IGF1 could promote the proliferation and differentiation of antler chondrocytes. Furthermore, IRS1/2 might act downstream of IGF1 to regulate chondrocyte differentiation through targeting RUNX1.

  13. Cardiac Overexpression of Insulin-Like Growth Factor I (IGF-1) Attenuates Chronic Alcohol Intake-Induced Myocardial Contractile Dysfunction But Not Hypertrophy: Role of Akt, mTOR, GSK3β and PTEN

    PubMed Central

    Zhang, Bingfang; Turdi, Subat; Li, Quan; Lopez, Faye L.; Eason, Anna R.; Anversa, Piero; Ren, Jun

    2010-01-01

    Chronic alcohol intake leads to the development of alcoholic cardiomyopathy manifested by cardiac hypertrophy and contractile dysfunction. This study was designed to examine the effect of transgenic overexpression of insulin-like growth factor I (IGF-1) on alcohol-induced cardiac contractile dysfunction. Wild-type FVB and cardiac-specific IGF-1 mice were placed on a 4% alcohol or control diet for 16 weeks. Cardiac geometry and mechanical function were evaluated by echocardiography, cardiomyocyte and intracellular Ca2+ properties. Histological analyses for cardiac fibrosis and apoptosis were evaluated by Masson trichrome staining and TUNEL assay, respectively. Expression and/or phosphorylation of Cu/Zn superoxide dismutase (SOD1), Ca2+ handling proteins, key signaling molecules for survival including Akt, mTOR, GSK3β, Foxo3a and the negative regulator of Akt phosphatase and tensin homolog on chromosome ten (PTEN) as well as mitochondrial proteins UCP-2 and PGC1α were evaluated by western blot analysis. Chronic alcohol intake led to cardiac hypertrophy, interstitial fibrosis, reduced mitochondrial number, compromised cardiac contractile function and intracellular Ca2+ handling, decreased SOD1 expression, elevated superoxide production and overt apoptosis, all of which with the exception of cardiac hypertrophy were abrogated by the IGF-1 transgene. Immunoblotting data showed reduced phosphorylation of Akt, mTOR, GSK3β and Foxo3a, upregulated Foxo3a and PTEN, as well as dampened SERCA2a, PGC1α and UCP-2 following alcohol intake. All these alcohol-induced changes in survival and mitochondrial proteins were alleviated by IGF-1. Taken together, these data favor a beneficial role of IGF-1 in alcohol-induced myocardial contractile dysfunction independent of cardiac hypertrophy. PMID:20678571

  14. Lifelong exercise and mild (8%) caloric restriction attenuate age-induced alterations in plantaris muscle morphology, oxidative stress and IGF-1 in the Fischer-344 rat.

    PubMed

    Kim, Jong-Hee; Kwak, Hyo-Bum; Leeuwenburgh, Christiaan; Lawler, John M

    2008-04-01

    Muscle atrophy is a highly prevalent condition among older adults, and results from reduced muscle mass and fiber cross-sectional area. Resistive exercise training and moderate (30-40%) caloric restriction may reduce the rate of sarcopenia in animal models. We tested the hypothesis that lifelong, voluntary exercise combined with mild (8%) caloric restriction would attenuate the reduction of muscle fiber cross-sectional area in the rat plantaris. Fischer-344 rats were divided into: young adults (6 mo) fed ad libitum (YAL); 24 mo old fed ad libitum (OAL); 24 mo old on 8% caloric restriction (OCR); lifelong wheel running with 8% CR (OExCR). Plantaris fiber cross-sectional area was significantly lower in OAL than YAL (-27%), but protected in OCR and OExCR, while mass/body mass ratio was preserved in OExCR only. Furthermore, 8% CR and lifelong wheel running attenuated the age-induced increases in extramyocyte space and connective tissue. Citrate synthase activity decreased with age, but was not significantly protected in OCR and OExCR. Total hydroperoxides were higher in OAL than YAL, but were not elevated in OExCR, with out a change in MnSOD. IGF-1 levels were lower in OAL (-57%) than YAL, but partially protected in the OExCR group (+51%).

  15. 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

  16. 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.

  17. miR-96, miR-145 and miR-9 expression increases, and IGF-1R and FOXO1 expression decreases in peripheral blood mononuclear cells of aging humans.

    PubMed

    Budzinska, Monika; Owczarz, Magdalena; Pawlik-Pachucka, Eliza; Roszkowska-Gancarz, Malgorzata; Slusarczyk, Przemyslaw; Puzianowska-Kuznicka, Monika

    2016-11-30

    In mammals, the IGF-1 pathway affects the phenotype of aging. Since the function of the immune system is modulated by IGF-1, it is plausible that immunosenescence might in part result from altered control by this pathway. We therefore examined whether the expression of IGF-1R, FOXO1, and FOXO3a in peripheral blood mononuclear cells (PBMC) changes with age and if this might be due to changes in the expression of select miRNAs. The expression of IGF-1R, FOXO1, FOXO3a, as well as of miR-9, miR-96, miR-99a, miR-132, miR-145, and miR-182 was examined in PBMC of young (27.8 ± 3.7 years), elderly (65.6 ± 3.4 years), and long-lived (94.0 ± 3.7 years) Polish Caucasians using real-time PCR. mRNA/miRNA interactions were studied in HEK 293 cells using luciferase-expressing pmirGLO reporter vector. The median expression of IGF-1R decreased with age (p < 0.000001), as did the expression of FOXO1 (p < 0.000001), while the expression of FOXO3a remained stable. We also found an age-associated increase of the median expression of miR-96 (p = 0.002), miR-145 (p = 0.024) and miR-9 (p = 0.026), decrease of the expression of miR-99a (p = 0.037), and no changes regarding miR-132 and miR-182. Functional studies revealed that miR-96 and miR-182 interacted with human IGF-1R mRNA, and that miR-145 and miR-132 interacted with human FOXO1 mRNA. The age-associated higher expression of miR-96 and miR-145 might contribute to the lower expression of IGF-1R while the higher expression of miR-96, miR-145 and miR-9 might contribute to the lower expression of FOXO1 in peripheral blood mononuclear cells of aging humans. Sustained expression/function of FOXO3a but not of the other two genes might be important for the maintenance of the immune system function in these individuals.

  18. Increased insulin-like growth factor 1 receptor (IGF1R) expression in small cell lung cancer and the effect of inhibition of IGF1R expression by RNAi on growth of human small cell lung cancer NCI-H446 cell.

    PubMed

    Wang, Zhigang; Lu, Pingfang; Liang, Zhu; Zhang, Zhanfei; Shi, Weicheng; Cai, Xiaobi; Chen, Chunyuan

    2015-01-01

    Insulin-like growth factor 1 receptor (IGF1R) is a tyrosine kinase receptor implicated in tumourigenesis that may be an attractive target for anti-cancer treatment. In this study, the expression and clinical significance of IGF1R were investigated in serum and lung cancer tissues from small cell lung cancinoma (SCLC). We also compared the effect of IGF1R up-regulation and IGF1R inhibition on viability and apoptosis of NCI-H446 cells. We found the concentration of IGF1R in blood serum was significantly increased and positive IGF1R protein in cancer tissue was more prevalent in SCLC. A statistically significant correlation among IGF1R-positve tumors, lymph node metastasis and local invasion was discussed. Furthermore, IGF1R overexpression lead to an increase of cell survival and suppressed cell apoptosis, IGF1R silencing mediated by RNAi abrogate this response of NCI-H446 cells. Our results further demonstrated that the effects of these treatments may be assigned to the effective inhibition of lung cancer cells from Akt/P27(Kip1) pathway in IGF-1R signaling. These features may have important implications for future anti-IGF1R therapeutic approaches.

  19. 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.

  20. 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

  1. IGF-1R and mTOR Blockade: Novel Resistance Mechanisms and Synergistic Drug Combinations for Ewing Sarcoma.

    PubMed

    Lamhamedi-Cherradi, Salah-Eddine; Menegaz, Brian A; Ramamoorthy, Vandhana; Vishwamitra, Deeksha; Wang, Ying; Maywald, Rebecca L; Buford, Adriana S; Fokt, Izabela; Skora, Stanislaw; Wang, Jing; Naing, Aung; Lazar, Alexander J; Rohren, Eric M; Daw, Najat C; Subbiah, Vivek; Benjamin, Robert S; Ratan, Ravin; Priebe, Waldemar; Mikos, Antonios G; Amin, Hesham M; Ludwig, Joseph A

    2016-12-01

    Therapies cotargeting insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) have demonstrated remarkable, albeit short-lived, clinical responses in a subset of Ewing sarcoma (ES) patients. However, the mechanisms of resistance and applicable strategies for overcoming drug resistance to the IGF-1R/mTOR blockade are still undefined. To elucidate predominant mechanism(s) of acquired drug resistance while identifying synergistic drug combinations that improve clinical efficacy, we generated more than 18 ES cell lines resistant to IGF-1R- or mTOR-targeted therapy. Two small-molecule inhibitors of IGF-1R were chosen, NVP-ADW-742 (IGF-1R-selective) and OSI-906 (a dual IGF-1R/insulin receptor alpha [IR-α] inhibitor). Reverse-phase protein lysate arrays (RPPAs) revealed proteomic changes linked to IGF-1R/mTOR resistance, and selected proteins were validated in cell-based assays, xenografts, and within human clinical samples. All statistical tests were two-sided. Novel mechanisms of resistance (MOR) emerged after dalotuzumab-, NVP-ADW-742-, and OSI-906-based targeting of IGF-1R. MOR to dalotuzumab included upregulation of IRS1, PI3K, and STAT3, as well as p38 MAPK, which was also induced by OSI-906. pEIF4E(Ser209), a key regulator of Cap-dependent translation, was induced in ridaforolimus-resistant ES cell lines. Unique drug combinations targeting IGF-1R and PI3K-alpha or Mnk and mTOR were synergistic in vivo and vitro (P < .001) as assessed respectively by Mantel-Cox and isobologram testing. We discovered new druggable targets expressed by chemoresistant ES cells, xenografts, and relapsed human tumors. Joint suppression of these newfound targets, in concert with IGF-1R or mTOR blockade, should improve clinical outcomes. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. 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.

  3. 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. Published by Elsevier Inc.

  4. Racial differences in IGF1 methylation and birth weight.

    PubMed

    Straughen, Jennifer K; Sipahi, Levent; Uddin, Monica; Misra, Dawn P; Misra, Vinod K

    2015-01-01

    The birth weight of Black neonates in the United States is consistently smaller than that of their White counterparts. Epigenetic differences between the races may be involved in such disparities. The goal of these analyses was to model the role of IGF1 methylation in mediating the association between race and birth weight. Data was collected on a cohort of 87 live born infants. IGF1 methylation was measured in DNA isolated from the mononuclear fraction of umbilical cord blood collected after delivery. Quantitative, loci-specific methylation was assessed using the Infinium HumanMethylation27 BeadArray (Illumina Inc., San Diego, CA). Locus specific methylation of the IGF1 CpG site was validated on a subset of the original sample (N = 61) using pyrosequencing. Multiple linear regression was used to examine relationships between IGF1 methylation, race, and birth weight. A formal mediation analysis was then used to estimate the relationship of IGF1 methylation to race and birth weight. Black race was associated with a 7.45% decrease in gestational age-adjusted birth weight (aBW) (P = 0.04) and Black infants had significantly higher IGF1 methylation than non-Black infants (P < 0.05). A one standard deviation increase in IGF1 methylation was associated with a 3.32% decrease in aBW (P = 0.02). Including IGF1 methylation as a covariate, the effect of Black race on aBW was attenuated. A formal mediation analysis showed that the controlled direct effect of Black race on aBW was -6.26% (95% CI = -14.15, 1.06); the total effect of Black race on IGF1 methylation was -8.12% (95% CI = -16.08, -0.55); and the natural indirect effect of Black race on aBW through IGF1 methylation was -1.86% (95% CI = -5.22, 0.18). The results of the mediation analysis along with the multivariable regression analyses suggest that IGF1 methylation may partially mediate the relationship between Black race and aBW. Such epigenetic differences may be involved in racial

  5. IGF-1R peptide vaccines/mimics inhibit the growth of BxPC3 and JIMT-1 cancer cells and exhibit synergistic antitumor effects with HER-1 and HER-2 peptides.

    PubMed

    Foy, Kevin Chu; Miller, Megan J; Overholser, Jay; Donnelly, Siobhan M; Nahta, Rita; Kaumaya, Pravin Tp

    2014-11-01

    The insulin-like growth factor-1 receptor (IGF-1R) plays a crucial role in cellular growth, proliferation, transformation, and inhibition of apoptosis. A myriad of human cancer types have been shown to overexpress IGF-1R, including breast and pancreatic adenocarcinoma. IGF-1R signaling interferes with numerous receptor pathways, rendering tumor cells resistant to chemotherapy, anti-hormonal therapy, and epidermal growth factor receptor (EGFR, also known as HER-1) and v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2, (ERBB2, best known as HER-2) -targeted therapies. Targeting the IGF:IGF-1R axis with innovative peptide inhibitors and vaccine antibodies thus represents a promising therapeutic strategy to overcome drug resistance and to provide new avenues for individualized and combinatorial treatment strategies. In this study, we designed, synthesized, and characterized several B-cell epitopes from the IGF-1:IGF-1R axis. The chimeric peptide epitopes were highly immunogenic in outbred rabbits, eliciting high levels of peptide vaccine antibodies. The IGF-1R peptide antibodies and peptide mimics inhibited cell proliferation and receptor phosphorylation, induced apoptosis and antibody-dependent cellular cytotoxicity (ADCC), and significantly inhibited tumor growth in the transplantable BxPC-3 pancreatic and JIMT-1 breast cancer models. Our results showed that the peptides and antibodies targeting residues 56-81 and 233-251 are potential therapeutic and vaccine candidates for the treatment of IGF-1R-expressing cancers, including those that are resistant to the HER-2-targeted antibody, trastuzumab. Additionally, we found additive antitumor effects for the combination treatment of the IGF-1R 56-81 epitope with HER-1-418 and HER-2-597 epitopes. Treatment with the IGF-1R/HER-1 or IGF-1R/HER-2 combination inhibited proliferation, invasion, and receptor phosphorylation, and induced apoptosis and ADCC, to a greater degree than single agents.

  6. 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

  7. The Glycolytic Inhibitor 2-Deoxyglucose Activates Multiple Prosurvival Pathways through IGF1R*

    PubMed Central

    Zhong, Diansheng; Xiong, Li; Liu, Tongrui; Liu, Xiuju; Liu, Xiangguo; Chen, Jing; Sun, Shi-Yong; Khuri, Fadlo R.; Zong, Yaping; Zhou, Qinghua; Zhou, Wei

    2009-01-01

    Recent molecular studies indicate that aerobic glycolysis plays an important role in tumorigenesis and is a valid target for cancer therapy. Although 2-deoxyglucose (2-DG) is well characterized as a glycolytic inhibitor, we recently discovered that it activates a prosurvival oncoprotein, AKT, through PI3K. In this study, we discovered that 2-DG treatments disrupted the binding between insulin-like growth factor 1 (IGF-1) and IGF-binding protein 3 (IGFBP3) so that the free form of IGF-1 could be released from the IGF-1·IGFBP3 complex to activate IGF-1 receptor (IGF1R) signaling. Because IGF1R signaling is involved, PI3K/AKT constitutes only one of the prosurvival pathways that are activated by 2-DG treatment; we validated that MEK-ERK signaling was also induced in an IGF1R-dependent manner in some cancer cell lines. Furthermore, our phospho-specific antibody microarray analysis indicated that 2-DG up-regulated the phosphorylation of 64 sites within various signaling pathways in H460 cells. Chemical inhibition of IGF1R reduced 57 of these up-regulations. These data suggest that 2-DG-induced activation of many survival pathways can be jointly attenuated through IGF1R inhibition. Our in vitro analysis demonstrated that treatment with a combination of subtoxic doses of 2-DG and the IGF1R inhibitor II reduced cancer cell proliferation 90% and promoted significant apoptosis. PMID:19574224

  8. 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.

  9. Unbound (bioavailable) IGF1 enhances somatic growth

    PubMed Central

    Elis, Sebastien; Wu, Yingjie; Courtland, Hayden-William; Cannata, Dara; Sun, Hui; Beth-On, Mordechay; Liu, Chengyu; Jasper, Hector; Domené, Horacio; Karabatas, Liliana; Guida, Clara; Basta-Pljakic, Jelena; Cardoso, Luis; Rosen, Clifford J.; Frystyk, Jan; Yakar, Shoshana

    2011-01-01

    SUMMARY Understanding insulin-like growth factor-1 (IGF1) biology is of particular importance because, apart from its role in mediating growth, it plays key roles in cellular transformation, organ regeneration, immune function, development of the musculoskeletal system and aging. IGF1 bioactivity is modulated by its binding to IGF-binding proteins (IGFBPs) and the acid labile subunit (ALS), which are present in serum and tissues. To determine whether IGF1 binding to IGFBPs is necessary to facilitate normal growth and development, we used a gene-targeting approach and generated two novel knock-in mouse models of mutated IGF1, in which the native Igf1 gene was replaced by Des-Igf1 (KID mice) or R3-Igf1 (KIR mice). The KID and KIR mutant proteins have reduced affinity for the IGFBPs, and therefore present as unbound IGF1, or ‘free IGF1’. We found that both KID and KIR mice have reduced serum IGF1 levels and a concomitant increase in serum growth hormone levels. Ternary complex formation of IGF1 with the IGFBPs and the ALS was markedly reduced in sera from KID and KIR mice compared with wild type. Both mutant mice showed increased body weight, body and bone lengths, and relative lean mass. We found selective organomegaly of the spleen, kidneys and uterus, enhanced mammary gland complexity, and increased skeletal acquisition. The KID and KIR models show unequivocally that IGF1-complex formation with the IGFBPs is fundamental for establishing normal body and organ size, and that uncontrolled IGF bioactivity could lead to pathological conditions. PMID:21628395

  10. 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.

  11. Epigenetics: intrauterine growth retardation (IUGR) modifies the histone code along the rat hepatic IGF-1 gene

    PubMed Central

    Fu, Qi; Yu, Xing; Callaway, Christopher W.; Lane, Robert H.; McKnight, Robert A.

    2009-01-01

    Intrauterine growth restriction (IUGR) decreases serum insulin growth factor-1 (IGF-1) levels. IGF-1 is an epigenetically regulated gene that has two promoters, alternative exon 5 splicing, and multiple termination sites. The regulation of gene expression involves the whole gene, as evidenced by the aforementioned IGF-1 paradigm. We hypothesized that IUGR in the rat would affect hepatic IGF-1 expression and alter the epigenetic characteristics of the IGF-1 gene along its length. IUGR was induced through a bilateral uterine artery ligation of the pregnant rat, a well-characterized model of IUGR. Pups from anesthesia and sham-operated dams were used as controls. Real-time RT-PCR and ELISA was used to measure expression at day of life (DOL) 0 and 21. Bisulfite sequencing and chromatin immunoprecipitation (ChIP) quantified IGF-1 epigenetic characteristics. A nontranscribed intergenic control was used for ChIP studies. IUGR decreased hepatic and serum IGF-1. Concurrently, IUGR modified epigenetic characteristics, particularly the histone code, along the length of the hepatic IGF-1 gene. Many changes persisted postnatally, and the postnatal effect of IUGR on the histone code was gender-specific. We conclude that IUGR modifies epigenetic characteristics of the rat hepatic IGF-1 gene along the length of the whole gene.—Fu, Q., Yu, X., Callaway, C. W., Lane, R. H., McKnight, R. A. Epigenetics: intrauterine growth retardation (IUGR) modifies the histone code along the rat hepatic IGF-1 gene. PMID:19364764

  12. 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

  13. IGF-1 Prevents Diastolic and Systolic Dysfunction Associated with Cardiomyopathy and Preserves Adrenergic Sensitivity

    PubMed Central

    Roof, Steve R.; Boslett, James; Russell, Duncan; del Rio, Carlos; Alecusan, Joe; Zweier, Jay L.; Ziolo, Mark T.; Hamlin, Robert; Mohler, Peter J.; Curran, Jerry

    2015-01-01

    Aims Insulin-like growth factor 1 (IGF-1)-dependent signaling promotes exercise-induced physiological cardiac hypertrophy. However, the in vivo therapeutic potential of IGF-1 for heart disease is not well established. Here we test the potential therapeutic benefits of IGF-1 on cardiac function using an in vivo model of chronic catecholamine-induced cardiomyopathy. Methods Rats were perfused with isoproterenol via osmotic pump (1 mg/kg/day) and treated with 2 mg/kg IGF-1 (2 mg/kg/day, 6 days a week) for 2 or 4 weeks. Echocardiography, ECG, and blood pressure were assessed. In vivo pressure-volume loop studies were conducted at 4 weeks. Heart sections were analyzed for fibrosis and apoptosis, and relevant biochemical signaling cascades were assessed. Results After 4 weeks, diastolic function (EDPVR, EDP, tau, E/A ratio), systolic function (PRSW, ESPVR, dP/dtmax), and structural remodeling (LV chamber diameter, wall thickness) were all adversely affected in isoproterenol-treated rats. All these detrimental effects were attenuated in rats treated with Iso+IGF-1. Isoproterenol-dependent effects on BP were attenuated by IGF-1 treatment. Adrenergic sensitivity was blunted in isoproterenol-treated rats but was preserved by IGF-1 treatment. Immunoblots indicate that cardioprotective p110α signaling and activated Akt are selectively upregulated in Iso+IGF-1 treated hearts. Expression of iNOS was significantly increased in both the Iso and Iso+IGF-1 groups, however tetrahydrobiopterin (BH4) levels were decreased in the Iso group and maintained by IGF-1 treatment. Conclusion IGF-1 treatment attenuates diastolic and systolic dysfunction associated with chronic catecholamine-induced cardiomyopathy while preserving adrenergic sensitivity and promoting BH4 production. These data support the potential use of IGF-1 therapy for clinical applications for cardiomyopathies. PMID:26399932

  14. 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

  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 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

  17. IGF-1 has sexually dimorphic, pleiotropic, and time-dependent effects on healthspan, pathology, and lifespan.

    PubMed

    Ashpole, Nicole M; Logan, Sreemathi; Yabluchanskiy, Andriy; Mitschelen, Matthew C; Yan, Han; Farley, Julie A; Hodges, Erik L; Ungvari, Zoltan; Csiszar, Anna; Chen, Sixia; Georgescu, Constantin; Hubbard, Gene B; Ikeno, Yuji; Sonntag, William E

    2017-04-01

    Reduced circulating levels of IGF-1 have been proposed as a conserved anti-aging mechanism that contributes to increased lifespan in diverse experimental models. However, IGF-1 has also been shown to be essential for normal development and the maintenance of tissue function late into the lifespan. These disparate findings suggest that IGF-1 may be a pleiotropic modulator of health and aging, as reductions in IGF-1 may be beneficial for one aspect of aging, but detrimental for another. We postulated that the effects of IGF-1 on tissue health and function in advanced age are dependent on the tissue, the sex of the animal, and the age at which IGF-1 is manipulated. In this study, we examined how alterations in IGF-1 levels at multiple stages of development and aging influence overall lifespan, healthspan, and pathology. Specifically, we investigated the effects of perinatal, post-pubertal, and late-adult onset IGF-1 deficiency using genetic and viral approaches in both male and female igf (f/f) C57Bl/6 mice. Our results support the concept that IGF-1 levels early during lifespan establish the conditions necessary for subsequent healthspan and pathological changes that contribute to aging. Nevertheless, these changes are specific for each sex and tissue. Importantly, late-life IGF-1 deficiency (a time point relevant for human studies) reduces cancer risk but does not increase lifespan. Overall, our results indicate that the levels of IGF-1 during development influence late-life pathology, suggesting that IGF-1 is a developmental driver of healthspan, pathology, and lifespan.

  18. 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

  19. IGF-1 Gene Expression in Rat Colonic Mucosa After Different Exercise Volumes

    PubMed Central

    Buehlmeyer, Katja; Doering, Frank; Daniel, Hannelore; Petridou, Anatoli; Mougios, Vassilis; Schulz, Thorsten; Michna, Horst

    2007-01-01

    The evidence is increasing for a close link between the insulin/insulin-like growth factor (IGF) system and colon cancer prevention by physical exercise. To reveal exercise-induced alterations in colon mucosa, gene expression of IGF-1 and related genes and serum IGF-1 were investigated. Twenty male Wistar rats performed a 12 week voluntary exercise program. Nine rats served as the control group. Gene expression of IGF-1, IGF-1 receptor (IGF-1R) and IGF-binding protein 3 (IGF-BP3) were quantified by real-time RT-PCR. Circulating IGF-1 was analyzed exercise volume-dependent. Based on 3 distinguished groups with low (L-EX, <2629 m·night-1), medium (M-EX, 3003-7458 m·night-1) and high exercise volume (H-EX, >8314 m·night-1), we observed lower serum IGF-1 levels (P < 0.05) in all exercise groups as compared to the control group and IGF-1 levels declined proportional to the increase in exercise volume. A significant (p < 0.05) positive correlation was found between IGF-1 concentration and body mass (r = 0.50) and a significant negative correlation exists between body mass and exercise volume (r = -0.50). Significant differences in colonic mRNA levels of IGF-1, IGF-1R and IGF-BP3 could not be observed. Based on our data we propose that the exercise as well as the body mass reduction leads to a decrease in circulating IGF-1 and this might represent a prime link to colon cancer prevention. Key pointsThere were significantly lower serum IGF-1 levels in all exercise groups as compared to the control group.GF-1 levels declined proportional to the increase in exercise volume.A significant positive correlation was found between IGF-1 concentration and body mass and a significant negative correlation was found between body mass and exercise volume.Significant differences in colonic mRNA levels of IGF-1, IGF-1R and IGF-BP3 could not be observed. PMID:24149475

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

    PubMed Central

    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

    2015-01-01

    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-EGFPLow) and reserve/facultative ISCs (Sox9-EGFPHigh) 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-EGFPLow ISCs and percentage of these cells in M-phase. IGF1 increased percentages of Sox9-EGFPHigh 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-EGFPHigh facultative ISCs but not Sox9-EGFPLow 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.—Van Landeghem, L., Santoro, M. A., Mah, A. T., Krebs, A. E., Dehmer, J. J., McNaughton, K. K., Helmrath, M. A., Magness, S. T., Lund, P. K. IGF1 stimulates crypt expansion via differential activation of 2 intestinal stem cell populations. PMID:25837582

  3. 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

  4. A kinase-independent biological activity for insulin growth factor-1 receptor (IGF-1R) : implications for inhibition of the IGF-1R signal.

    PubMed

    Janku, Filip; Huang, Helen J; Angelo, Laura S; Kurzrock, Razelle

    2013-03-01

    It has been demonstrated that epidermal growth factor receptor (EGFR) can have kinase independent activity. EGFR kinase-independent function maintains intracellular glucose levels via sodium glucose transporter protein 1 (SGLT1) and supports cell survival. It is plausible that this phenomenon can apply to other receptor tyrosine kinases. We found that transfection of insulin-like growth factor receptor (IGF-1R) siRNA into HEK293 (human embryonic kidney) and MCF7 (metastatic breast cancer) cells result in decreased intracellular glucose levels, whereas treatment with an IGF-1R tyrosine kinase inhibitor OSI-906 did not affect intracellular glucose levels. In addition, IGF-1R interacted with SGLT1 in a manner similar to that previously reported with EGFR. The combination of IGF-1R siRNA and OSI-906 resulted in decreased viability of HEK293 and MCF7 cell lines compared to either agent alone. Collectively, these experiments suggest that IGF-1R, has kinase-independent biologic functions and provide a rationale for combining anti-IGF-1R antibodies or siRNA and IGF-1R small molecule inhibitors.

  5. 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.

  6. 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.

  7. Obesity and metabolic dysfunction severely influence prostate cell function: role of insulin and IGF1.

    PubMed

    L-López, Fernando; Sarmento-Cabral, André; Herrero-Aguayo, Vicente; Gahete, Manuel D; Castaño, Justo P; Luque, Raúl M

    2017-09-01

    Obesity is a major health problem that courses with severe comorbidities and a drastic impairment of homeostasis and function of several organs, including the prostate gland (PG). The endocrine-metabolic regulatory axis comprising growth hormone (GH), insulin and IGF1, which is drastically altered under extreme metabolic conditions such as obesity, also plays relevant roles in the development, modulation and homeostasis of the PG. However, its implication in the pathophysiological interplay between obesity and prostate function is still to be elucidated. To explore this association, we used a high fat-diet obese mouse model, as well as in vitro primary cultures of normal-mouse PG cells and human prostate cancer cell lines. This approach revealed that most of the components of the GH/insulin/IGF1 regulatory axis are present in PGs, where their expression pattern is altered under obesity conditions and after an acute insulin treatment (e.g. Igfbp3), which might have some pathophysiological implications. Moreover, our results demonstrate, for the first time, that the PG becomes severely insulin resistant under diet-induced obesity in mice. Finally, use of in vitro approaches served to confirm and expand the conception that insulin and IGF1 play a direct, relevant role in the control of normal and pathological PG cell function. Altogether, these results uncover a fine, germane crosstalk between the endocrine-metabolic status and the development and homeostasis of the PG, wherein key components of the GH, insulin and IGF1 axes could play a relevant pathophysiological role. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  8. IGF-1 bioavailability is increased by resistance training in older women with low bone mineral density.

    PubMed

    Parkhouse, W S; Coupland, D C; Li, C; Vanderhoek, K J

    2000-02-07

    We investigated if long-term resistance training would increase insulin-like growth factor-1 (IGF-1) bioavailabilty at rest in older women (68+/-1 years) with low bone mineral density. IGF-1 levels were significantly lower (P<0.05), and insulin-like growth factor binding proteins -1 and -3 (IGFBP-1 and IGFBP-3) significantly higher than an age-matched healthy normal group. Resistance training resulted in significant (P<0.05) increases in repetition maximums across all exercises (range 41-78%). Resting IGF-1 levels were significantly (P<0.05) elevated (70%) by the resistance training whereas no significant changes occurred in IGFBP-1 and IGFBP-3 levels. IGFBP-1/IGF-1 and IGFBP-3/IGF-1 ratios were significantly decreased (approximately - 50%) as a result of resistance training (P<0.05). Thus, IGF-1 bioavailability was increased as a result of resistance training induced increases in IGF-1 levels in older women with low bone mineral density. These alterations in the IGF-1 system may be contributing to the significant strength gain observed with the resistance training in this population.

  9. 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

  10. 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

  11. Complement component 1, q subcomponent binding protein (C1QBP) in lipid rafts mediates hepatic metastasis of pancreatic cancer by regulating IGF-1/IGF-1R signaling.

    PubMed

    Shi, Haojun; Fang, Winston; Liu, Minda; Fu, Deliang

    2017-10-01

    Pancreatic cancer shows a remarkable predilection for hepatic metastasis. Complement component 1, q subcomponent binding protein (C1QBP) can mediate growth factor-induced cancer cell chemotaxis and distant metastasis by activation of receptor tyrosine kinases. Coincidentally, insulin-like growth factor-1 (IGF-1) derived from the liver and cancer cells itself has been recognized as a critical inducer of hepatic metastasis. However, the mechanism underlying IGF-1-dependent hepatic metastasis of pancreatic cancer, in which C1QBP may be involved, remains unknown. In the study, we demonstrated a significant association between C1QBP expression and hepatic metastasis in patients with pancreatic cancer. IGF-1 induced the translocation of C1QBP from cytoplasm to lipid rafts and further drove the formation of CD44 variant 6 (CD44v6)/C1QBP complex in pancreatic cancer cells. C1QBP interacting with CD44v6 in lipid rafts promoted phosphorylation of IGF-1R and thus activated downstream PI3K and MAPK signaling pathways which mediated metastatic potential of pancreatic cancer cells including proliferation, apoptosis, invasion, adhesion and energy metabolism. Furthermore, C1QBP knockdown suppressed hepatic metastasis of pancreatic cancer cells in nude mice. We therefore conclude that C1QBP in lipid rafts serves a key regulator of IGF-1/IGF-1R-induced hepatic metastasis from pancreatic cancer. Our findings about C1QBP in lipid rafts provide a novel strategy to block IGF-1/IGF-1R signaling in pancreatic cancer and a reliable premise for more efficient combined modality therapies. © 2017 UICC.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. IGF-1R Inhibition Activates a YES/SFK Bypass Resistance Pathway: Rational Basis for Co-Targeting IGF-1R and Yes/SFK Kinase in Rhabdomyosarcoma1

    PubMed Central

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

    2015-01-01

    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. PMID:25925378

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Aging, Synaptic Dysfunction, and Insulin-Like Growth Factor (IGF)-1

    PubMed Central

    Deak, Ferenc

    2012-01-01

    Insulin-like growth factor (IGF)-1 is an important neurotrophic hormone. Deficiency of this hormone has been reported to influence the genesis of cognitive impairment and dementia in the elderly patients. Nevertheless, there are studies indicating that cognitive function can be maintained into old age even in the absence of circulating IGF-1 and studies that link IGF-1 to an acceleration of neurological diseases. Although IGF-1 has a complex role in brain function, synaptic effects appear to be central to the IGF-1induced improvement in learning and memory. In this review, synaptic mechanisms of learning and memory and the effects of IGF-1 on synaptic communication are discussed. The emerging data indicate that synaptic function decreases with age and that IGF-1 contributes to information processing in the brain. Further studies that detail the specific actions of this important neurotrophic hormone will likely lead to therapies that result in improved cognitive function for the elderly patients. PMID:22503992

  6. IGF-1 modulates gene expression of proteins involved in inflammation, cytoskeleton, and liver architecture.

    PubMed

    Lara-Diaz, V J; Castilla-Cortazar, I; Martín-Estal, I; García-Magariño, M; Aguirre, G A; Puche, J E; de la Garza, R G; Morales, L A; Muñoz, U

    2017-05-01

    Even though the liver synthesizes most of circulating IGF-1, it lacks its receptor under physiological conditions. However, according to previous studies, a damaged liver expresses the receptor. For this reason, herein, we examine hepatic histology and expression of genes encoding proteins of the cytoskeleton, extracellular matrix, and cell-cell molecules and inflammation-related proteins. A partial IGF-1 deficiency murine model was used to investigate IGF-1's effects on liver by comparing wild-type controls, heterozygous igf1(+/-), and heterozygous mice treated with IGF-1 for 10 days. Histology, microarray for mRNA gene expression, RT-qPCR, and lipid peroxidation were assessed. Microarray analyses revealed significant underexpression of igf1 in heterozygous mice compared to control mice, restoring normal liver expression after treatment, which then normalized its circulating levels. IGF-1 receptor mRNA was overexpressed in Hz mice liver, while treated mice displayed a similar expression to that of the controls. Heterozygous mice showed overexpression of several genes encoding proteins related to inflammatory and acute-phase proteins and underexpression or overexpression of genes which coded for extracellular matrix, cytoskeleton, and cell junction components. Histology revealed an altered hepatic architecture. In addition, liver oxidative damage was found increased in the heterozygous group. The mere IGF-1 partial deficiency is associated with relevant alterations of the hepatic architecture and expression of genes involved in cytoskeleton, hepatocyte polarity, cell junctions, and extracellular matrix proteins. Moreover, it induces hepatic expression of the IGF-1 receptor and elevated acute-phase and inflammation mediators, which all resulted in liver oxidative damage.

  7. Can we unlock the potential of IGF-1R inhibition in cancer therapy?

    PubMed Central

    King, Helen; Aleksic, Tamara; Haluska, Paul; Macaulay, Valentine M.

    2014-01-01

    IGF-1R inhibitors arrived in the clinic accompanied by optimism based on preclinical activity of IGF-1R targeting, and recognition that low IGF bioactivity protects from cancer. This was tempered by concerns about toxicity to normal tissue IGF-1R and cross-reactivity with insulin receptor (InsR). In fact, toxicity is not a show-stopper; the key issue is efficacy. While IGF-1R inhibition induces responses as monotherapy in sarcomas and with chemotherapy or targeted agents in common cancers, negative Phase 2/3 trials in unselected patients prompted the cessation of several Pharma programs. Here, we review completed and on-going trials of IGF-1R antibodies, kinase inhibitors and ligand antibodies. We assess candidate bio-markers for patient selection, highlighting the potential predictive value of circulating IGFs/IGFBPs, the need for standardized assays for IGF-1R, and preclinical evidence that variant InsRs mediate resistance to IGF-1R antibodies. We review hypothesis-led and unbiased approaches to evaluate IGF-1R inhibitors with other agents, and stress the need to consider sequencing with chemotherapy. The last few years were a tough time for IGF-1R therapeutics, but also brought progress in understanding IGF biology. Even failed studies include patients who derived benefit; they should be investigated to identify features distinguishing the tumors and host environment of responders from non-responders. We emphasize the importance of incorporating biospecimen collection into trial design, and wording patient consents to allow post hoc analysis of trial material as new data become available. Such information represents the key to unlocking the potential of this approach, to inform the next generation of trials of IGF signalling inhibitors. PMID:25123819

  8. Muscle Protein Catabolism After Severe Burn: Effects of IGF-1/IGFBP-3 Treatment

    PubMed Central

    Herndon, David N.; Ramzy, Peter I.; DebRoy, Meelie A.; Zheng, Ming; Ferrando, Arny A.; Chinkes, David L.; Barret, Juan P.; Wolfe, Robert R.; Wolf, Steven E.

    1999-01-01

    Objective To determine the effects of recombinant human insulin-like growth factor-1 (IGF-1) complexed with its principal binding protein, IGFBP-3, on skeletal muscle metabolism in severely burned children. Summary Background Data Severe burns are associated with a persistent hypermetabolic response characterized by hyperdynamic circulation and severe muscle catabolism and wasting. Previous studies showed that nutritional support and pharmacologic intervention with anabolic agents such as growth hormone and insulin abrogated muscle wasting and improved net protein synthesis in the severely burned. The use of these agents, however, has several adverse side effects. A new combination of IGF-1 and IGFBP-3 is now available for clinical study. Methods Twenty-nine severely burned children were prospectively studied before and after treatment with 0.5, 1, 2, or 4 mg/kg/day IGF-1/IGFBP-3 to determine net balance of protein across the leg, muscle protein fractional synthetic rates, and glucose metabolism. Another group was studied in a similar fashion without IGF-1/IGFBP-3 treatment as time controls. Results Seventeen of 29 children were catabolic before starting treatment. The infusion of 1.0 mg/kg/day IGF-1/IGFBP-3 increased serum IGF-1, which did not further increase with 2.0 and 4.0 mg/kg/day. IGF-1/IGFBP-3 treatment at 1 to 4 mg/kg/day improved net protein balance and increased muscle protein fractional synthetic rates. This effect was more pronounced in catabolic children. IGF-1/IGFBP-3 did not affect glucose uptake across the leg or change substrate utilization. Conclusions IGF-1/IGFBP-3 at doses of 1 to 4 mg/kg/day attenuates catabolism in catabolic burned children with negligible clinical side effects. PMID:10235530

  9. Hepatic-Specific Accessibility of Igf1 Gene Enhancers Is Independent of Growth Hormone Signaling

    PubMed Central

    Santhanam, Mahalakshmi

    2013-01-01

    The diverse roles of IGF-1 in physiology include acting as the endocrine intermediate to elicit the anabolic actions of GH. The majority of serum IGF-1 is synthesized in liver, where GH stimulates Igf1 gene transcription via the transcription factor, signal transducer and activator of transcription (Stat)5b. We and others have identified multiple Stat5-binding domains at the Igf1 locus that function in gene regulation, but it remains unclear whether the roles of these domains are tissue specific. Survey of the chromatin landscape of regulatory domains can provide insight about mechanisms of gene regulation, with chromatin accessibility regarded as a hallmark feature of regulatory domains. We prepared chromatin from liver, kidney, and spleen of C57BL/6 mice, and used formaldehyde-associated isolation of regulatory elements to assess chromatin accessibility at the major Igf1 promoter and 7 -binding enhancers. Whereas the promoters of other prototypical tissue-specific genes are open in a tissue-specific way, the major Igf1 promoter is open in all 3 tissues, albeit moderately more so in liver. In contrast, chromatin accessibility at Igf1 Stat5-binding domains is essentially restricted to liver, indicating that the enhancers are driving extensive differences in tissue expression. Furthermore, studies with Ghrhrlit/lit mice reveal that prior GH exposure is not necessary to establish open chromatin at these domains. Lastly, formaldehyde-associated isolation of regulatory elements of human liver samples confirms open chromatin at IGF1 Promoter 1, but unexpectedly, homologous Stat5-binding motifs are not accessible. We conclude that robust GH-stimulated hepatic Igf1 gene transcription utilizes tissue-specific mechanisms of epigenetic regulation that are established independent of GH signaling. PMID:24109593

  10. Kinase inhibitors of the IGF-1R as a potential therapeutic agent for rheumatoid arthritis.

    PubMed

    Tsushima, Hiroshi; Morimoto, Shinji; Fujishiro, Maki; Yoshida, Yuko; Hayakawa, Kunihiro; Hirai, Takuya; Miyashita, Tomoko; Ikeda, Keigo; Yamaji, Ken; Takamori, Kenji; Takasaki, Yoshinari; Sekigawa, Iwao; Tamura, Naoto

    2017-08-01

    We have previously shown that the inhibition of connective tissue growth factor (CTGF) is a potential therapeutic strategy against rheumatoid arthritis (RA). CTGF consists of four distinct modules, including the insulin-like growth factor binding protein (IGFBP). In serum, insulin-like growth factors (IGFs) bind IGFBPs, interact with the IGF-1 receptor (IGF-1 R), and regulate anabolic effects and bone metabolism. We investigated the correlation between IGF-1 and the pathogenesis of RA, and the inhibitory effect on osteoclastogenesis and angiogenesis of the small molecular weight kinase inhibitor of the IGF-1 R, NVP-AEW541, against pathogenesis of RA in vitro. Cell proliferation was evaluated by cell count and immunoblotting. The expression of IGF-1 and IGF-1 R was evaluated by RT-PCR. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase staining, a bone resorption assay, and osteoclast-specific enzyme production. Angiogenesis was evaluated by a tube formation assay using human umbilical vein endothelial cells (HUVECs). The proliferation of MH7A cells was found to be inhibited in the presence of NVP-AEW541, and the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt was downregulated in MH7A cells. IGF-1 and IGF-1 R mRNA expression levels were upregulated during formation of M-colony stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL)-mediated osteoclast formation. Moreover, osteoclastogenesis was suppressed in the presence of NVP-AEW541. The formation of the tubular network was enhanced by IGF-1, and this effect was neutralized by NVP-ARE541. Our findings suggest that NVP-AEW541 may be utilized as a potential therapeutic agent in the treatment of RA.

  11. Serum IGF-1, IGFBP-3 and their ratio: Potential biochemical growth maturity indicators.

    PubMed

    Jain, Nimisha; Tripathi, Tulika; Gupta, S K; Rai, Priyank; Kanase, Anup; Kalra, Shilpa

    2017-12-01

    Determination of skeletal maturation and remaining growth potential is an essential part of treatment planning in orthodontics. The aim of our study was to determine the relationship between IGF-1 levels, IGFBP-3 levels with CVM staging to track the pre pubertal and pubertal growth spurts in female patients in North Indian population. This cross-sectional study was conducted on ninety female subjects in the age group of 8-20 years. Blood samples were collected and centrifuged and serum samples were then analysed by Human IGF-1 and IGFBP-3 enzyme-linked immunosorbent assay kits, specific for IGF-1 and IGFBP-3, respectively. CVM staging on lateral cephalometric radiograph was determined for all patients. Analysis of variance test followed by a post hoc test was used to compare mean IGF-1 and IGFBP-3 corresponding to six stages of cervical vertebrae maturation stages. Linear Pearson's correlations were performed to determine the trends of IGF-1, IGFBP-3, and its ratio relating to CVM stage. The kappa statistic was used to measure inter and intra examiner reliability. P value <0.05 was considered as statistically significant. Mean serum IGF-1 levels were found to be highest (403.3 ± 12.3 ng/ml) at CVMI3 stage of CVMI. The post-hoc test revealed a significant difference in IGF-1 levels between all stages of CVMI, thereby indicating a specific range of IGF-1 levels for a specific skeletal stage. Mean serum IGFBP-3 levels were found to be highest (5186.8 ± 1384.2 ng/ml) at CVMI4 stage of CVMI. The mean serum IGFBP-3 levels at CVMI4 were found to be significantly higher than the levels at all other CVMI stages except CVMI3 stage. IGF-1 and IGFBP-3 can serve as a potential biochemical indicator for assessment of skeletal maturity.

  12. Precise mapping of an IGF-I-binding site on the IGF-1R.

    PubMed

    Keyhanfar, Mehrnaz; Booker, Grant W; Whittaker, Jonathan; Wallace, John C; Forbes, Briony E

    2007-01-01

    The IGF-1R [type 1 IGF (insulin-like growth factor) receptor] is activated upon binding to IGF-I and IGF-II leading to cell growth, survival and migration of both normal and cancerous cells. We have characterized the binding interaction between the IGF-1R and its ligands using two high-affinity mouse anti-IGF-1R mAbs (monoclonal antibodies), 7C2 and 9E11. These mAbs both block IGF-I binding to the IGF-1R but have no effect on IGF-II binding. Epitope mapping using chimaeras of the IGF-1R and insulin receptor revealed that the mAbs bind to the CR (cysteine-rich) domain of IGF-1R. The epitope was finely mapped using single point mutations in the IGF-1R. Mutation of Phe241, Phe251 or Phe266 completely abolished 7C2 and 9E11 binding. The three-dimensional structure showed that these residues cluster on the surface of the CR-domain. BIAcore analyses revealed that IGF-I and a chimaeric IGF-II with the IGF-I C-domain competed for the binding of both mAbs with the IGF-1R, whereas neither IGF-II nor a chimaeric IGF-I with the IGF-II C-domain affected antibody binding. We therefore conclude the IGF-I C-domain interacts with the CR (cysteine-rich) domain of the receptor at the cluster of residues Phe241, Phe251 and Phe266. These results allow precise orientation of IGF-I within the IGF-I-IGF-1R complex involving the IGF-I C-domain binding to the IGF-1R CR domain. In addition, mAbs 7C2 and 9E11 inhibited both IGF-I- and IGF-II-induced cancer cell proliferation, migration and IGF-1R down-regulation, demonstrating that targeting the IGF-1R is an effective strategy for inhibition of cancer cell growth.

  13. 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

  14. 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

  15. VEGF/Neuropilin-2 Regulation of Bmi-1 and Consequent Repression of IGF-1R Define a Novel Mechanism of Aggressive Prostate Cancer

    PubMed Central

    Goel, Hira Lal; Chang, Cheng; Pursell, Bryan; Leav, Irwin; Lyle, Stephen; Xi, Hualin Simon; Hsieh, Chung-Cheng; Adisetiyo, Helty; Roy-Burman, Pradip; Coleman, Ilsa M.; Nelson, Peter S.; Vessella, Robert L.; Davis, Roger J.; Plymate, Stephen R.; Mercurio, Arthur M.

    2014-01-01

    We demonstrate that the VEGF receptor, neuropilin-2 (NRP2) is associated with high-grade, PTEN-null prostate cancer and that its expression in tumor cells is induced by PTEN loss as a consequence of c-Jun activation. VEGF/NRP2 signaling represses IGF-1R expression and signaling and the mechanism involves Bmi-1-mediated transcriptional repression of the IGF-1R. This mechanism has significant functional and therapeutic implications that were evaluated. IGF-1R expression correlates with PTEN and inversely with NRP2 in prostate tumors. NRP2 is a robust biomarker for predicting response to IGF-1R therapy because prostate carcinomas that express NRP2 exhibit low levels of IGF-1R. Conversely, targeting NRP2 is only modestly effective because NRP2 inhibition induces compensatory IGF-1R signaling. Inhibition of both NRP2 and IGF-1R, however, completely blocks tumor growth in vivo. PMID:22777769

  16. 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.

  17. 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

  18. Ganglioside GM3 depletion reverses impaired wound healing in diabetic mice by activating IGF-1 and insulin receptors.

    PubMed

    Wang, Xiao-Qi; Lee, Sarah; Wilson, Heather; Seeger, Mark; Iordanov, Hristo; Gatla, Nandita; Whittington, Adam; Bach, Daniel; Lu, Jian-Yun; Paller, Amy S

    2014-05-01

    Ganglioside GM3 mediates adipocyte insulin resistance, but the role of GM3 in diabetic wound healing, a major cause of morbidity, is unclear. The purpose of this study was to determine whether GM3 depletion promotes diabetic wound healing and directly activates keratinocyte (KC) insulin pathway signaling. GM3 synthase (GM3S) expression is increased in human diabetic foot skin, ob/ob and diet-induced obese diabetic mouse skin, and in mouse KCs exposed to increased glucose. GM3S knockout in diet-induced obese mice prevents the diabetic wound-healing defect. KC proliferation, migration, and activation of insulin receptor (IR) and insulin growth factor-1 receptor (IGF-1R) are suppressed by excess glucose in wild-type cells, but increased in GM3S (-/-) KCs with supplemental glucose. Co-immunoprecipitation of IR, IR substrate 1 (IRS-1), and IGF-1R, and increased IRS-1 and Akt phosphorylation accompany receptor activation. GM3 supplementation or inhibition of IGF-1R or PI3K reverses the increased migration of GM3S(-/-) KCs, whereas IR knockdown only partially suppresses migration.

  19. Enforced epithelial expression of IGF-1 causes hyperplastic prostate growth while negative selection is requisite for spontaneous metastogenesis

    USDA-ARS?s Scientific Manuscript database

    The insulin-like growth factor-1 (IGF-1) signaling axis is important for cell growth, differentiation, and survival, and increased serum IGF is a risk factor for prostate and other cancers. To study IGF-1 action on the prostate, we created transgenic (PB-Des) mice that specifically express human IGF...

  20. 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.

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

    PubMed Central

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

    2010-01-01

    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. PMID:20228935

  2. HIV/HCV Co-infection, Liver Disease Progression, and Age-Related IGF-1 Decline.

    PubMed

    Quinn, Jeffrey; Astemborski, Jacquie; Mehta, Shruti H; Kirk, Gregory D; Thomas, David L; Balagopal, Ashwin

    2017-01-01

    We have previously reported that persons co-infected with HIV and hepatitis C virus (HCV) had liver disease stages similar to HIV-uninfected individuals who were approximately 10 years older. Insulin-like growth factor 1(IGF-1) levels have long been known to decline with advancing age in humans and non-humans alike. We examined whether HIV infection affects the expected decline in IGF-1 in persons with chronic hepatitis C virus (HCV) infection and if that alteration in IGF-1 decline contributes to the link between HIV, aging, and liver disease progression. A total of 553 individuals with HCV infection were studied from the AIDS Linked to the Intravenous Experience (ALIVE) cohort for whom more than 10 years of follow-up was available. Serum IGF-1 levels were determined by ELISA and evaluated according to baseline characteristics and over time by HIV status and liver disease progression. Linear regression with generalized estimating equations was used to determine whether IGF-1 decline over time was independently associated with liver disease progression. Baseline IGF-1 levels were strongly associated with age (P < 0.0001) but not with gender or HIV infection. Levels of IGF-1 declined at a rate of -1.75 ng/mL each year in HCV mono-infected individuals and at a rate of -1.23 ng/mL each year in HIV/HCV co-infected individuals (P < 0.05). In a multivariable linear regression model, progression of liver fibrosis was associated with HIV infection and age, as well as with a slower rate of IGF-1 decline (P = 0.001); however, the rate of IGF-1 decline did not alter the strength of the associations between HIV, liver disease, and age. The normal decline in IGF-1 levels with age was attenuated in HIV/HCV co-infected individuals compared to those with HCV mono-infection, and slower IGF-1 decline was independently associated with liver disease progression.

  3. 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.

  4. The adipokine leptin mediates muscle- and liver-derived IGF-1 in aged mice.

    PubMed

    Hamrick, M W; Dukes, A; Arounleut, P; Davis, C; Periyasamy-Thandavan, S; Mork, S; Herberg, S; Johnson, M H; Isales, C M; Hill, W D; Otvos, L; Belin de Chantemèle, E J

    2015-10-01

    Muscle- and liver-derived IGF-1 play important roles in muscle anabolism throughout growth and aging. Yet, prolonged food restriction is thought to increase longevity in part by lowering levels of IGF-1, which in turn reduces the risk for developing various cancers. The dietary factors that modulate IGF-1 levels are, however, poorly understood. We tested the hypothesis that the adipokine leptin, which is elevated with food intake and suppressed during fasting, is a key mediator of IGF-1 levels with aging and food restriction. First, leptin levels in peripheral tissues were measured in young mice fed ad libitum, aged mice fed ad libitum, and aged calorie-restricted (CR) mice. A group of aged CR mice were also treated with recombinant leptin for 10 days. Later, aged mice fed ad libitum were treated with saline (VEH) or with a novel leptin receptor antagonist peptide (Allo-aca) and tissue-specific levels of IGF-1 were determined. On one hand, recombinant leptin induced a three-fold increase in liver-derived IGF-1 and a two-fold increase in muscle-derived IGF-1 in aged, CR mice. Leptin also significantly increased serum growth hormone levels in the aged, CR mice. On the other, the leptin receptor antagonist Allo-aca did not alter body weight or muscle mass in treated mice compared to VEH mice. Allo-aca did, however, produce a significant (20%) decline in liver-derived IGF-1 as well as an even more pronounced (>50%) decrease in muscle-derived IGF-1 compared to VEH-treated mice. The reduced IGF-1 levels in Allo-aca treated mice were not accompanied by any significant change in growth hormone levels compared to VEH mice. These findings suggest that leptin receptor antagonists may represent novel therapeutic agents for attenuating IGF-1 signaling associated with aging, and could potentially mimic some of the positive effects of calorie restriction on longevity. Copyright © 2015 Elsevier Inc. All rights reserved.

  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. The effects of IGF-1 on mouse spermatogenesis using an organ culture method.

    PubMed

    Yao, Jianfei; Zuo, Haiyang; Gao, Jun; Wang, Mingming; Wang, Dong; Li, Xiangdong

    2017-09-23

    Currently available organ culture methods can induce the differentiation of spermatogonial stem cells (SSCs) to spermatids in vitro, but the percentages of haploid cells and elongated spermatids are extremely low. The goal of this study was to test strategies to increase the differentiation rate of SSCs into elongated spermatids in vitro. RNA-seq was performed from forty round spermatids isolated by laser capture microdissection from cultured mouse testicular fragments (MTFs) or 27 days post-partum testes. Gene Ontology (GO) and KEGG analysis of the transcriptome revealed that many cell cycle and apoptosis-associated genes were among the differently expressed genes. Quantitative real-time PCR confirmed that the expression of Ccnd3 decreased and the expression of Trp53, Casp8 and Cyct increased in round spermatids from cultured MTFs. As insulin-like growth factor (IGF-1) can regulate cell cycle and apoptosis of many kinds of cells, the expression of Igf-1 decreased in cultured MTFs and IGF-1 receptor expressed strongly in germ cells, IGF-1 was added to the basal medium. IGF-1 increased the percentages of round and elongated spermatids by decreasing the apoptosis of germ cells and increasing the density of germ cells in cultured MTFs. These results indicate that IGF-1 plays a critical role in spermatogenesis from SSCs. Copyright © 2017. Published by Elsevier Inc.

  7. 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.

  8. AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice.

    PubMed

    Mallol, Cristina; Casana, Estefania; Jimenez, Veronica; Casellas, Alba; Haurigot, Virginia; Jambrina, Claudia; Sacristan, Victor; Morró, Meritxell; Agudo, Judith; Vilà, Laia; Bosch, Fatima

    2017-07-01

    Type 1 diabetes is characterized by autoimmune destruction of β-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding β-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for β-cells with immunomodulatory properties. Transgenic NOD mice overexpressing IGF1 specifically in β-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28-30 weeks. In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of β-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved β-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a

  9. Vitamin D increases circulating IGF1 in adults: potential implication for the treatment of GH deficiency.

    PubMed

    Ameri, Pietro; Giusti, Andrea; Boschetti, Mara; Bovio, Marta; Teti, Claudia; Leoncini, Giovanna; Ferone, Diego; Murialdo, Giovanni; Minuto, Francesco

    2013-12-01

    Previous studies suggested that vitamin D modulates circulating IGF1. We investigated this effect in adults and its clinical relevance in the management of GH deficiency (GHD). IGF1 levels were prospectively measured before and after 12 weeks of treatment with oral vitamin D3 (5000 or 7000 IU/week) vs no intervention in 39 subjects 61.9±7.9 years old. The frequency of IGF1 values ≥50th age- and sex-specific percentile in relation to vitamin D status, as determined by the concentration of 25-hydroxyvitamin D (25(OH)D), was retrospectively assessed in 69 GHD patients (57.4±16.6 years) on stable hormone replacement and with 25(OH)D and IGF1 concurrently measured. Treatment with 5000 and 7000 IU vitamin D3/week significantly raised 25(OH)D by 12.7±8.4 and 13.1±6.5 ng/ml respectively (both P<0.001 vs baseline). In the 7000 IU group, IGF1 levels also significantly increased by 31.3±36.7 ng/ml (P=0.01). Neither 25(OH)D nor IGF1 significantly varied in controls. IGF1 was ≥50th percentile more frequently in GHD patients with 25(OH)D levels ≥15 than <15 ng/ml (65.9 vs 40.0%, P<0.05). Logistic regression with adjustment for recombinant human GH (rhGH) dose, vitamin D supplements, gender, use of thyroid hormones, corticosteroids or estrogen/testosterone, and season revealed a significant positive association between ≥15 ng/ml 25(OH)D and IGF1 ≥50th percentile (OR 4.4, 95% CI 1.0-18.8, P<0.05). A significant negative correlation between 25(OH)D concentrations and rhGH dose was found after correcting for age and IGF1 (β -0.042, P<0.01), but not after further adjusting for sex, thyroid, adrenal or gonadal replacement, and season (β -0.037, P=0.06). Vitamin D increases circulating IGF1 in adults. As a result, a better vitamin D status may ease the achievement of normal IGF1 values in GHD.

  10. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. 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

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

    PubMed

    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.

  13. Anabolic effects of IGF-1 signaling on the skeleton

    PubMed Central

    Tahimic, Candice G. T.; Wang, Yongmei; Bikle, Daniel D.

    2013-01-01

    This review focuses on the anabolic effects of IGF-1 signaling on the skeleton, emphasizing the requirement for IGF-1 signaling in normal bone formation and remodeling. We first discuss the genomic context, splicing variants, and species conservation of the IGF-1 locus. The modulation of IGF-1 action by growth hormone (GH) is then reviewed while also discussing the current model which takes into account the GH-independent actions of IGF-1. Next, the skeletal phenotypes of IGF-1-deficient animals are described in both embryonic and postnatal stages of development, which include severe dwarfism and an undermineralized skeleton. We then highlight two mechanisms by which IGF-1 exerts its anabolic action on the skeleton. Firstly, the role of IGF-1 signaling in the modulation of anabolic effects of parathyroid hormone (PTH) on bone will be discussed, presenting in vitro and in vivo studies that establish this concept and the proposed underlying molecular mechanisms involving Indian hedgehog (Ihh) and the ephrins. Secondly, the crosstalk of IGF-1 signaling with mechanosensing pathways will be discussed, beginning with the observation that animals subjected to skeletal unloading by hindlimb elevation are unable to mitigate cessation of bone growth despite infusion with IGF-1 and the failure of IGF-1 to activate its receptor in bone marrow stromal cell cultures from unloaded bone. Disrupted crosstalk between IGF-1 signaling and the integrin mechanotransduction pathways is discussed as one of the potential mechanisms for this IGF-1 resistance. Next, emerging paradigms on bone-muscle crosstalk are examined, focusing on the potential role of IGF-1 signaling in modulating such interactions. Finally, we present a future outlook on IGF research. PMID:23382729

  14. 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

  15. 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

  16. 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.

  17. 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.

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

    PubMed Central

    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

    2014-01-01

    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. PMID:24633053

  19. 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

  20. 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

  1. AAV-2-mediated expression of IGF-1 in skeletal myoblasts stimulates angiogenesis and cell survival.

    PubMed

    Subramanian, Indira V; Fernandes, Brian C A; Robinson, Timothy; Koening, Jennifer; Lapara, Kelly S; Ramakrishnan, S

    2009-03-01

    The transplantation of skeletal myoblasts is being tested in various organ systems to facilitate tissue repair and regeneration. Previous studies have indicated that transplanted cells for varied reasons were not surviving in sufficient numbers following transplantation, thus negatively affecting overall therapeutic efficacy of the approach. We hypothesize that the genetic modification of myoblasts to express insulin-like growth factor 1 (IGF-1) locally may enhance the survival of transplanted cells by stimulating neo-vascularization, decreasing apoptosis, and promoting cell proliferation. Using an adeno-associated virus (adeno-associated virus type 2) vector system, the IGF-1 gene was introduced into canine skeletal myoblasts. As a negative control, myoblasts transduced with the green fluorescence protein (GFP) was used. Relative angiogenic response induced by IGF-1 myoblast was compared to VEGF165-induced neo-vascularization using Matrigel plugs under similar conditions. In vitro evaluation and characterization revealed that the secreted IGF-1 protein was biologically and functionally active in promoting endothelial cell proliferation, migration and assembly into vessel-like structures. Matrigel plugs containing the three test groups were implanted subcutaneously in nude mice (n = 5). After 3 weeks, analysis of explanted samples revealed an enhanced neo-vascularization with an average microvessel density per field for IGF-1 at 55.9 versus 33.4 for vascular endothelial growth factor and 24 for GFP. Additionally, apoptosis was significantly reduced (p IGF-1-transduced myoblasts. We conclude that the genetic modification of skeletal myoblasts with the IGF-1 gene offers a potential means for enhanced cell survival following transplantation.

  2. A microsatellite polymorphism in IGF1 gene promoter and timing of natural menopause in Caucasian women.

    PubMed

    Kaczmarek, Maria; Pacholska-Bogalska, Joanna; Kwaśniewski, Wojciech; Kotarski, Jan; Halerz-Nowakowska, Barbara; Goździka-Józefiak, Anna

    2015-01-01

    Genes involved in the IGF-1 aging pathways in the human ovary can be considered strong candidates for predictors of the natural menopause timing. This study evaluates the association between a cytosine-adenine (CA) microsatellite polymorphism in the IGF1 gene promoter P1 and age at natural menopause. Genomic DNA was extracted from the peripheral blood, PCR was performed using primers designed to amplify the polymorphic (CA) n repeat of the human IGF1 gene, an allele dose effect for the most common (CA)19 repeats allele, Cox proportional hazard regression models and the Kaplan-Meier cumulative survivorship method with the log-rank test were used to determine statistical significance of studied associations in a sample of 257 Polish women aged 40-58 years. Crude Cox proportional hazard regression analysis confirmed the association between the IGF1 gene polymorphism and the menopause timing (p=0.038). This relationship remained statistically significant after controlling for other menopause confounders in multivariate modelling. Out of the input variables, the (CA)n polymorphism in the IGF1 gene promoter, age at menarche and smoking status were independent covariates of the natural menopause timing (χ2=12.845; df=3; p=0.034). The onset of menopause at a younger age was likely associated with the IGF1 genotype variant not carrying the (CA)19 repeats allele, menarche before the age of 12 and a current cigarette smoker status (HR=1.6). This study provides evidence that a common cytosine-adenine (CA) microsatellite repeat polymorphism in the P1 promoter region of the IGF1 gene is an independent predictive factor for age at natural menopause in Caucasian women also after adjusting for other menopause covariates.

  3. DHT and IGF-1 in peripheral blood lymphocytes: new markers for the biological passport of athletes.

    PubMed

    Mancini, A; Imperlini, E; Alfieri, A; Spaziani, S; Martone, D; Parisi, A; Orru, S; Buono, P

    2013-01-01

    We performed a pilot study using human peripheral blood lymphocytes (PBL) as a novel system to identify new biomarkers of dihydrotestosterone (DHT) and insulin-like growth factor-1 (IGF-1) abuse in sport. First, to obtain a gene signature, we treated cultures of lymphocytes from sedentary males with three doses of 0.237 microg/ml DHT, each of which is 80-fold the physiological concentration in young adult male serum, at days 0, 2 and 4, or with a single dose of 1.25 microg/ml IGF-1, which is 5-fold the physiological concentration in young adult male serum. We then used the Human Genome U133 Plus 2.0 microarray to identify a gene signature related to DHT or IGF-1 administration. Gene expression was evaluated after 7 and 21 days of DHT treatment, and after 24 h, 72 h and 7 days of IGF-1 treatment. Microarray analysis yielded a list of genes whose expression was altered after DHT or IGF-1 treatment. Among these we selected the genes that are most representative of the pathways associated with skeletal and muscular disorders using the IPA bioinformatics tool. We identified six (IDO1, CXCL13, CCL1, GZMB, VDR and IL2RA) and two (FN1 and RAB31) genes that were up-regulated in lymphocytes from sedentary subjects after 7 days of DHT and IGF-1 treatment, respectively. The expression of these genes in lymphocytes from differently trained athletes was either down-regulated or similar to that in lymphocytes from sedentary subjects. This finding suggests that up-regulation was due to the drug and not to physical exercise. In conclusion, we demonstrate that PBL can be useful in anti-doping checks, and we describe new biomarkers of DHT and IGF-1 abuse which can be included in the Athlete's Biological Passport.

  4. 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.

  5. 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

  6. Elevated IGFBP3 levels in diabetic tears: a negative regulator of IGF-1 signaling in the corneal epithelium

    PubMed Central

    Wu, Yu-Chieh; Buckner, Benjamin R.; Zhu, Meifang; Cavanagh, H. Dwight; Robertson, Danielle M.

    2012-01-01

    Purpose To determine the ratio of IGFBP3:IGF-1 in normal and diabetic human tears, and in telomerase-immortalized human corneal epithelial cells (hTCEpi) cultured under elevated glucose conditions and to correlate these changes with total and phosphorylated levels of IGF-1R. Methods Tear samples were collected noninvasively from diabetic subjects and non-diabetic controls; corneal sensitivity was assessed using a Cochet-Bonnet Aesthesiometer. Conditioned media were collected following culture of hTCEpi cells in normal (5 mM) and elevated (25 mM) glucose conditions; mannitol was used as an osmotic control. IGFBP3, IGF-1, and phosphorylated IGF-1R levels were assessed by ELISA. IGFBP3 and IGF-1R mRNA were assessed by real time polymerase chain reaction (PCR). Total and phosphorylated IGF-1R expression in whole cell lysates was assessed by western blot. Results There was a 2.8-fold increase in IGFBP3 in diabetic tears compared to non-diabetic controls (P=0.006); IGF-1 levels were not significantly altered. No difference in corneal sensitivity was detected between groups. The concentration of IGFBP3 in tears was independent of IGF-1. Consistent with human tear measurements in vivo, IGFBP3 secretion was increased 2.2 fold (P<0.001) following culture of hTCEpi cells under elevated glucose conditions in vitro. Treatment with glucose and the mannitol control reduced IGFBP3 mRNA (P<0.001). Total IGF-1R levels were unchanged. The increase in the IGFBP3:IGF-1 ratio detected in diabetic tears compared to normal controls blocked phosphorylation of the IGF-1R by IGF-1 (P<0.001) when tested in vitro. Conclusions Taken together, these in vivo and confirmatory in vitro findings suggest that the observed increase in IGFBP3 found in human tears may attenuate IGF-1R signaling in the diabetic cornea. A long-term increase in IGFBP3 may contribute to epithelial compromise and the pathogenesis of ocular surface complications reported in diabetes. PMID:22482470

  7. Elevated IGFBP3 levels in diabetic tears: a negative regulator of IGF-1 signaling in the corneal epithelium.

    PubMed

    Wu, Yu-Chieh; Buckner, Benjamin R; Zhu, Meifang; Cavanagh, H Dwight; Robertson, Danielle M

    2012-04-01

    To determine the ratio of IGFBP3:IGF-1 in normal and diabetic human tears, and in telomerase-immortalized human corneal epithelial cells (hTCEpi) cultured under elevated glucose conditions and to correlate these changes with total and phosphorylated levels of IGF-1R. Tear samples were collected noninvasively from diabetic subjects and non-diabetic controls; corneal sensitivity was assessed using a Cochet-Bonnet Aesthesiometer. Conditioned media were collected following culture of hTCEpi cells in normal (5 mM) and elevated (25 mM) glucose conditions; mannitol was used as an osmotic control. IGFBP3, IGF-1, and phosphorylated IGF-1R levels were assessed by ELISA. IGFBP3 and IGF-1R mRNA were assessed by real-time polymerase chain reaction (PCR). Total and phosphorylated IGF-1R expression in whole cell lysates was assessed by western blot. There was a 2.8-fold increase in IGFBP3 in diabetic tears compared to non-diabetic controls (P=0.006); IGF-1 levels were not significantly altered. No difference in corneal sensitivity was detected between groups. The concentration of IGFBP3 in tears was independent of IGF-1. Consistent with human tear measurements in vivo, IGFBP3 secretion was increased 2.2 fold (P<0.001) following culture of hTCEpi cells under elevated glucose conditions in vitro. Treatment with glucose and the mannitol control reduced IGFBP3 mRNA (P<0.001). Total IGF-1R levels were unchanged. The increase in the IGFBP3:IGF-1 ratio detected in diabetic tears compared to normal controls blocked phosphorylation of the IGF-1R by IGF-1 (P<0.001) when tested in vitro. Taken together, these in vivo and confirmatory in vitro findings suggest that the observed increase in IGFBP3 found in human tears may attenuate IGF-1R signaling in the diabetic cornea. A long-term increase in IGFBP3 may contribute to epithelial compromise and the pathogenesis of ocular surface complications reported in diabetes. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. InsR/IGF1R pathway mediates resistance to EGFR inhibitors in glioblastoma

    PubMed Central

    Ma, Yufang; Tang, Nan; Thompson, Reid; Mobley, Bret C.; Clark, Steven W.; Sarkaria, Jann N.; Wang, Jialiang

    2015-01-01

    Purpose Aberrant activation of epidermal growth factor receptor (EGFR) is a hallmark of glioblastoma. However, EGFR inhibitors exhibit at best modest efficacy in glioblastoma. This is in sharp contrast to the observations in EGFR-mutant lung cancer. We examined whether activation of functionally redundant receptor tyrosine kinases (RTKs) conferred resistance to EGFR inhibitors in glioblastoma. Experimental Design We collected a panel of patient-derived glioblastoma xenograft (PDX) lines that maintained expression of wild type or mutant EGFR in serial xenotransplantation and tissue cultures. Using this physiologically relevant platform, we tested the abilities of several RTK ligands to protect glioblastoma cells against an EGFR inhibitor, gefitinib. Based on the screening results, we further developed a combination therapy co-targeting EGFR and insulin receptor (InsR)/insulin-like growth factor 1 receptor (IGF1R). Results Insulin and IGF1 induced significant protection against gefitinib in the majority of EGFR-dependent PDX lines with one exception that did not expression InsR or IGF1R. Blockade of the InsR/IGF1R pathway synergistically improved sensitivity to gefitinib or dacomitinib. Gefitinib alone effectively attenuated EGFR activities and the downstream MEK/ERK pathway. However, repression of AKT and induction of apoptosis required concurrent inhibition of both EGFR and InsR/IGF1R. A combination of gefitinib and OSI-906, a dual InsR/IGF1R inhibitor, was more effective than either agent alone to treat subcutaneous glioblastoma xenograft tumors. Conclusions Our results suggest that activation of the InsR/IGF1R pathway confers resistance to EGFR inhibitors in EGFR-dependent glioblastoma through AKT regulation. Concurrent blockade of these two pathways holds promise to treat EGFR-dependent glioblastoma. PMID:26561558

  9. 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.

  10. Relative IGF-1 and IGF-2 gene expression in maternal and fetal tissues from diabetic swine

    SciTech Connect

    Wolverton, C.K.; Leaman, D.W.; White, M.E.; Ramsay, T.G. )

    1990-02-26

    Fourteen pregnant, crossbred gilts were utilized in this study. Seven gilts were injected with alloxan (50 mg/kg) at day 75 of gestation to induce diabetes. Gilts underwent caesarean section on day 105 of gestation. Samples were collected from maternal skeletal muscle, adipose tissue, uterus and endometrium; and from fetal skeletal muscle, adipose tissue, placenta, liver, lung, kidney, heart, brain and spleen. Tissues were frozen in liquid nitrogen for later analysis of IGF-1 and IGF-2 gene expression. Samples were pooled and total RNA was isolated using the guanidine isothiocynate method. Total mRNA was analyzed by dot blot hybridization. Blots were probed with {sup 32}P-cDNA for porcine IGF-1 and rat IGF-2. IGF-1 gene expression in maternal tissues was unaffected by diabetes. Maternal diabetes increased IGF-2 mRNA in maternal adipose tissue but exhibited no effect in muscle or uterus. Expression of IGF-2 by maternal endometrium was decreased by diabetes. Maternal diabetes induced an increase in IGF-1 gene expression in muscle and placenta while causing an increase in IGF-2 expression in fetal liver and placenta. IGF-2 mRNA was lower in lung from fetuses of diabetic mothers than in controls. These results suggest that maternal diabetes alters IGF-1 and IGF-2 gene expression in specific tissues and differential regulation of these genes appears to exist in the mother and developing fetus.

  11. IGF-1 contributes to the expansion of melanoma-initiating cells through an epithelial-mesenchymal transition process.

    PubMed

    Le Coz, Vincent; Zhu, Chaobin; Devocelle, Aurore; Vazquez, Aimé; Boucheix, Claude; Azzi, Sandy; Gallerne, Cindy; Eid, Pierre; Lecourt, Séverine; Giron-Michel, Julien

    2016-12-13

    Melanoma is a particularly virulent human cancer, due to its resistance to conventional treatments and high frequency of metastasis. Melanomas contain a fraction of cells, the melanoma-initiating cells (MICs), responsible for tumor propagation and relapse. Identification of the molecular pathways supporting MICs is, therefore, vital for the development of targeted treatments. One factor produced by melanoma cells and their microenvironment, insulin-like growth factor-1 (IGF- 1), is linked to epithelial-mesenchymal transition (EMT) and stemness features in several cancers.We evaluated the effect of IGF-1 on the phenotype and chemoresistance of B16-F10 cells. IGF-1 inhibition in these cells prevented malignant cell proliferation, migration and invasion, and lung colony formation in immunodeficient mice. IGF-1 downregulation also markedly inhibited EMT, with low levels of ZEB1 and mesenchymal markers (N-cadherin, CD44, CD29, CD105) associated with high levels of E-cadherin and MITF, the major regulator of melanocyte differentiation. IGF-1 inhibition greatly reduced stemness features, including the expression of key stem markers (SOX2, Oct-3/4, CD24 and CD133), and the functional characteristics of MICs (melanosphere formation, aldehyde dehydrogenase activity, side population). These features were associated with a high degree of sensitivity to mitoxantrone treatment.In this study, we deciphered new connections between IGF-1 and stemness features and identified IGF-1 as instrumental for maintaining the MIC phenotype. The IGF1/IGF1-R nexus could be targeted for the development of more efficient anti-melanoma treatments. Blocking the IGF-1 pathway would improve the immune response, decrease the metastatic potential of tumor cells and sensitize melanoma cells to conventional treatments.

  12. 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.

  13. FOXO1 is regulated by insulin and IGF1 in pituitary gonadotropes.

    PubMed

    Skarra, Danalea V; Thackray, Varykina G

    2015-04-15

    The FOXO1 transcription factor is important for multiple aspects of reproductive function. We previously reported that FOXO1 functions as a repressor of gonadotropin hormone synthesis, but how FOXO1 is regulated in pituitary gonadotropes is unknown. The growth factors, insulin and insulin-like growth factor I (IGF1), function as key regulators of cell proliferation, metabolism and apoptosis in multiple cell types through the PI3K/AKT signaling pathway. In this study, we found that insulin and IGF1 signaling in gonadotropes induced FOXO1 phosphorylation through the PI3K/AKT pathway in immortalized and primary cells, resulting in FOXO1 relocation from the nucleus to the cytoplasm. Furthermore, insulin administration in vivo induced phosphorylation of FOXO1 and AKT in the pituitary. Thus, insulin and IGF1 act as negative regulators of FOXO1 activity and may serve to fine-tune gonadotropin expression. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. FOXO1 is Regulated by Insulin and IGF1 in Pituitary Gonadotropes

    PubMed Central

    Skarra, Danalea V.; Thackray, Varykina G.

    2015-01-01

    The FOXO1 transcription factor is important for multiple aspects of reproductive function. We previously reported that FOXO1 functions as a repressor of gonadotropin hormone synthesis, but how FOXO1 is regulated in pituitary gonadotropes is unknown. The growth factors, insulin and insulin-like growth factor I (IGF1) function as key regulators of cell proliferation, metabolism and apoptosis in multiple cell types through the PI3K/AKT signaling pathway. In this study, we found that insulin and IGF1 signaling in gonadotropes induced FOXO1 phosphorylation through the PI3K/AKT pathway in immortalized and primary cells, resulting in FOXO1 relocation from the nucleus to the cytoplasm. Furthermore, insulin administration in vivo induced phosphorylation of FOXO1 and AKT in the pituitary. Thus, insulin and IGF1 act as negative regulators of FOXO1 activity and may serve to fine-tune gonadotropin expression. PMID:25676570

  15. Proteomic Screening and Lasso Regression Reveal Differential Signaling in Insulin and Insulin-like Growth Factor I (IGF1) Pathways *

    PubMed Central

    Erdem, Cemal; Nagle, Alison M.; Casa, Angelo J.; Litzenburger, Beate C.; Wang, Yu-fen; Taylor, D. Lansing; Lee, Adrian V.; Lezon, Timothy R.

    2016-01-01

    Insulin and insulin-like growth factor I (IGF1) influence cancer risk and progression through poorly understood mechanisms. To better understand the roles of insulin and IGF1 signaling in breast cancer, we combined proteomic screening with computational network inference to uncover differences in IGF1 and insulin induced signaling. Using reverse phase protein array, we measured the levels of 134 proteins in 21 breast cancer cell lines stimulated with IGF1 or insulin for up to 48 h. We then constructed directed protein expression networks using three separate methods: (i) lasso regression, (ii) conventional matrix inversion, and (iii) entropy maximization. These networks, named here as the time translation models, were analyzed and the inferred interactions were ranked by differential magnitude to identify pathway differences. The two top candidates, chosen for experimental validation, were shown to regulate IGF1/insulin induced phosphorylation events. First, acetyl-CoA carboxylase (ACC) knock-down was shown to increase the level of mitogen-activated protein kinase (MAPK) phosphorylation. Second, stable knock-down of E-Cadherin increased the phospho-Akt protein levels. Both of the knock-down perturbations incurred phosphorylation responses stronger in IGF1 stimulated cells compared with insulin. Overall, the time-translation modeling coupled to wet-lab experiments has proven to be powerful in inferring differential interactions downstream of IGF1 and insulin signaling, in vitro. PMID:27364358

  16. miR-139 is up-regulated in osteoarthritis and inhibits chondrocyte proliferation and migration possibly via suppressing EIF4G2 and IGF1R

    SciTech Connect

    Hu, Weihua; Zhang, Weikai; Li, Feng; Guo, Fengjing; Chen, Anmin

    2016-05-27

    Osteoarthritis (OA) is one of the most progressive articular cartilage erosions. microRNAs (miRNAs) play pivotal roles in OA modulation, but the role of miR-139 in OA remains elusive. This study aims to reveal the effects and possible mechanism of miR-139 in OA and chondrocytes. The levels of miR-139 and its possible targets eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) and insulin-like growth factor 1 receptor (IGF1R) were detected by qRT-PCR in the articular cartilages of 20 OA patients and 20 non-OA patients. Human chondrocyte CHON-001 cells were transfected with miR-139 mimic or inhibitor, as well as the siRNAs of EIF4G2 and IGF1R. Cell viability by MTT assay, proliferation by colony formation assay and migration by Transwell assay were performed. Results showed that miR-139 was up-regulated, while EIF4G2 and IGF1R mRNAs down-regulated in OA cartilages (P < 0.001), and negative correlations existed between the level of miR-139 and EIF4G2 or IGF1R. Overexpression of miR-139 in CHON-001 cells suppressed both mRNA and protein levels of EIF4G2 and IGF1R, and inhibited cell viability, colony formation number and cell migration, while miR-139 inhibitor induced the opposite effects. Knockdown of EIF4G2 or IGF1R in CHON-001 cells reversed the effects of miR-139 inhibitor on cell viability, colony formation and cell migration. These results indicate that miR-139 is capable of inhibiting chondrocyte proliferation and migration, thus being a possible therapeutic target for OA. The mechanism of miR-139 in chondrocytes may be related to its regulation on EIF4G2 and IGF1R.

  17. Systemic Administration of a Recombinant AAV1 Vector Encoding IGF-1 Improves Disease Manifestations in SMA Mice

    PubMed Central

    Tsai, Li-Kai; Chen, Chien-Lin; Ting, Chen-Hung; Lin-Chao, Sue; Hwu, Wuh-Liang; Dodge, James C; Passini, Marco A; Cheng, Seng H

    2014-01-01

    Spinal muscular atrophy is a progressive motor neuron disease caused by a deficiency of survival motor neuron. In this study, we evaluated the efficacy of intravenous administration of a recombinant adeno-associated virus (AAV1) vector encoding human insulin-like growth factor-1 (IGF-1) in a severe mouse model of spinal muscular atrophy. Measurable quantities of human IGF-1 transcripts and protein were detected in the liver (up to 3 months postinjection) and in the serum indicating that IGF-1 was secreted from the liver into systemic circulation. Spinal muscular atrophy mice administered AAV1-IGF-1 on postnatal day 1 exhibited a lower extent of motor neuron degeneration, cardiac and muscle atrophy as well as a greater extent of innervation at the neuromuscular junctions compared to untreated controls at day 8 posttreatment. Importantly, treatment with AAV1-IGF-1 prolonged the animals' lifespan, increased their body weights and improved their motor coordination. Quantitative polymerase chain reaction and western blot analyses showed that AAV1-mediated expression of IGF-1 led to an increase in survival motor neuron transcript and protein levels in the spinal cord, brain, muscles, and heart. These data indicate that systemically delivered AAV1-IGF-1 can correct several of the biochemical and behavioral deficits in spinal muscular atrophy mice through increasing tissue levels of survival motor neuron. PMID:24814151

  18. Small-molecule inhibition and activation-loop trans-phosphorylation of the IGF1 receptor

    PubMed Central

    Wu, Jinhua; Li, Wanqing; Craddock, Barbara P; Foreman, Kenneth W; Mulvihill, Mark J; Ji, Qun-sheng; Miller, W Todd; Hubbard, Stevan R

    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. PMID:18566589

  19. 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

  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. 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.

  2. Generation and Screening of Monoclonal Antibodies for ImmunoPET Imaging of IGF1R in Prostate Cancer

    PubMed Central

    2015-01-01

    Insulin-like growth factor 1 receptor (IGF1R) plays an important role in proliferation, apoptosis, angiogenesis, and tumor invasion. The expression level of IGF1R is related to resistance to several targeted therapies. The goal of this study was to develop an immunoPET tracer for imaging of IGF1R in prostate cancer. Murine antibodies against human IGF1R were generated in BALB/c mice, which were screened in IGF1R-positive MCF-7 cells using flow cytometry as well as biodistribution studies with multiple 64Cu-labeled antibody clones. The antibody production method we adopted could readily produce milligram quantities of anti-IGF1R antibodies for in vivo studies. One antibody clone (1A2G11) with the highest affinity for IGF1R was selected and conjugated to NOTA for 64Cu-labeling. NOTA-1A2G11 maintained IGF1R specificity/avidity based on flow cytometry. 64Cu-labeling was achieved with good yield (>50%) and high specific activity (>1 Ci/μmol). Serial PET imaging revealed that uptake of 64Cu-NOTA-1A2G11 was 2.8 ± 0.7, 10.2 ± 2.6, and 9.6 ± 1.7 %ID/g in IGF1R-positive DU-145 tumors at 4, 24, and 48 h postinjection, respectively (n = 3), significantly higher than that in IGF1R-negative LNCaP tumors (<3 %ID/g at each time point) except at 4 h postinjection. Histology studies showed strong correlations between IGF1R expression level in the prostate cancer tumor tissues and tumor uptake of 64Cu-NOTA-1A2G11. Prominent, persistent, and IGF1R-specific uptake of 64Cu-NOTA-1A2G11 in IGF1R-positive prostate tumors holds strong potential for future cancer diagnosis, prognosis, and therapy using this antibody. PMID:25157758

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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. © 2015 International Federation for Cell Biology.

  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. The single IGF-1 partial deficiency is responsible for mitochondrial dysfunction and is restored by IGF-1 replacement therapy.

    PubMed

    Olleros Santos-Ruiz, M; Sádaba, M C; Martín-Estal, I; Muñoz, U; Sebal Neira, C; Castilla-Cortázar, I

    2017-08-01

    We previously described in cirrhosis and aging, both conditions of IGF-1 deficiency, a clear hepatic mitochondrial dysfunction with increased oxidative damage. In both conditions, the hepatic mitochondrial function was improved with low doses of IGF-1. The aim of this work was to explore if the only mere IGF-1 partial deficiency, without any exogenous insult, is responsible for hepatic mitochondrial dysfunction. Heterozygous (igf1(+/-)) mice were divided into two groups: untreated and treated mice with low doses of IGF-1. WT group was used as controls. Parameters of hepatic mitochondrial function were determined by flow cytometry, antioxidant enzyme activities were determined by spectrophotometry, and electron chain transport enzyme levels were determined by immunohistochemistry and immunofluorescence analyses. Liver expression of genes coding for proteins involved in mitochondrial protection and apoptosis was studied by microarray analysis and RT-qPCR. Hz mice showed a significant reduction in hepatic mitochondrial membrane potential (MMP) and ATPase activity, and an increase in intramitochondrial free radical production and proton leak rates, compared to controls. These parameters were normalized by IGF-1 replacement therapy. No significant differences were found between groups in oxygen consumption and antioxidant enzyme activities, except for catalase, whose activity was increased in both Hz groups. Relevant genes coding for proteins involved in mitochondrial protection and survival were altered in Hz group and were reverted to normal in Hz+IGF-1 group. The mere IGF-1 partial deficiency is per se associated with hepatic mitochondrial dysfunction sensitive to IGF-1 replacement therapy. Results in this work prove that IGF-1 is involved in hepatic mitochondrial protection, because it is able to reduce free radical production, oxidative damage and apoptosis. All these IGF-1 actions are mediated by the modulation of the expression of genes encoding citoprotective

  10. 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

  11. 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

  12. Initial testing of a monoclonal antibody (IMC-A12) against IGF-1R by the Pediatric Preclinical Testing Program.

    PubMed

    Houghton, Peter J; Morton, Christopher L; Gorlick, Richard; Kolb, E Anders; Keir, Stephen T; Reynolds, C Patrick; Kang, Min H; Maris, John M; Wu, Jianrong; Smith, Malcolm A

    2010-07-01

    Many childhood malignancies including sarcomas, neuroblastoma, and Wilms tumor show the presence of both, active, type-1-insulin-like growth factor receptor (IGF-1R), and the autocrine production of its ligands IGF-1/IGF-2. IMC-A12 is a fully human IgG1 antibody that prevents ligand binding to the IGF-1R. IMC-A12 was evaluated against the 23 cell lines of the Pediatric Preclinical Testing Program (PPTP) in vitro panel using 96 hr exposure at concentrations ranging from 0.01 nM to 0.1 microM. IMC-A12 was tested in vivo at a dose of 1 mg/mouse administered intraperitoneally twice weekly for 6 weeks. In vitro, IMC-A12-induced T/C values <50% in only three cell lines, a rhabdomyosarcoma cell line (Rh41) and two Ewing sarcoma cell lines (TC-71 and CHLA-9). In vivo, IMC-A12 induced significant differences in EFS distribution compared to control in 24 of 34 (71%) evaluable solid tumor xenografts. Using the PPTP "time to event" activity measure, IMC-A12 induced intermediate (n = 13) or high (n = 1) activity in 33 xenografts evaluable for this activity measure, including 6 of 6 rhabdomyosarcoma xenografts, 3 of 5 osteosarcoma xenografts, 2 of 5 neuroblastoma xenografts, and 1 of 5 Ewing sarcoma xenografts. The only objective response observed was observed in a rhabdomyosarcoma xenograft (Rh28) that achieved a maintained complete response. IMC-A12 demonstrated broad antitumor activity against the PPTP's in vivo solid tumor panels, with the activity primarily being tumor growth inhibition rather than tumor regression. IMC-A12 showed its greatest activity in vivo against the PPTP's rhabdomyosarcoma xenografts. Copyright 2010 Wiley-Liss, Inc.

  13. 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

  14. The Association between IGF-1 Polymorphisms, IGF-1 Serum Levels, and Cognitive Functions in Healthy Adults: The Amsterdam Growth and Health Longitudinal Study

    PubMed Central

    Licht, Carmilla M. M.; van Turenhout, Lise C.; Deijen, Jan Berend; Koppes, Lando L. J.; van Mechelen, Willem; Twisk, Jos W. R.; Drent, Madeleine L.

    2014-01-01

    Several studies have demonstrated an association between polymorphisms in the insulin-like growth factor-1 (IGF-1) gene and IGF-1 serum levels. IGF-1 levels have been associated with cognitive functioning in older persons and growth hormone deficient patients. The present study investigates whether IGF-1 polymorphisms, IGF-1 levels, and cognition are interconnected in healthy adults. Data of 277 participants (mean age: 42.4 years) of the Amsterdam Growth and Health Longitudinal Study on IGF-1 promoter polymorphisms, IGF-1 serum level, spatial working memory (SWM), paired associate learning (PAL), and IQ tests were analyzed. (M)ANOVAs were applied to confirm the associations between IGF-1 polymorphisms and IGF-1 levels and between IGF-1 levels and cognition. Three groups were distinguished based on specific IGF-1 polymorphism alleles: a homozygote 192 bp/192 bp genotype, a heterozygote 192 bp/x genotype, and a noncarrier x/x genotype. Although different IGF-1 levels were found for the three genotypes, performance on all cognitive tasks and IQ measures was similar. Despite the associations between IGF-1 polymorphisms and IGF-1 levels, no association was found between cognition and IGF-1 levels. It seems that IGF-1 does not play a role in the cognitive performance of healthy middle-aged adults. Possible, IGF-1 fulfills a more developmental and protective role in cognition which becomes apparent during childhood, old-age, or disease. PMID:25114679

  15. JiangTang XiaoKe granule attenuates cathepsin K expression and improves IGF-1 expression in the bone of high fat diet induced KK-Ay diabetic mice.

    PubMed

    Guo, Yubo; Wang, Lili; Ma, Rufeng; Mu, Qianqian; Yu, Na; Zhang, Yi; Tang, Yuqing; Li, Yu; Jiang, Guangjian; Zhao, Dandan; Mo, Fangfang; Gao, Sihua; Yang, Meijuan; Kan, Feifei; Ma, Qun; Fu, Min; Zhang, Dongwei

    2016-03-01

    To assess the beneficial effects of JiangTang XiaoKe (JTXK) granule on the bone metabolism in high fat diet (HFD) fed KK-Ay diabetic mice. The KK-Ay mice were used as a diabetic model, while C57BL/6 mice were utilized as the non-diabetic control. The left tibia was used for determining bone mineral density (BMD) and bone ash coefficient. The HE and alizarin red S staining of femur were employed to evaluate bone pathology and calcium deposition. The expressions of alkaline phosphatase (ALP), insulin growth factor 1 (IGF-1) and cathepsin K were assessed by western blotting and immunohistochemical staining. JTXK granule significantly improved the bone ash coefficient, the distribution of trabecular bone and the calcification nodules deposition in KK-Ay mice with diabetes. IGF-1 and ALP expressions were significantly decreased, and cathepsin K expression was dramatically increased in the HFD fed KK-Ay diabetic model mice, which can be reversed by JTXK granule treatment. JTXK granule at medium or high dosage was more efficient in improving diabetic bone quality when compared with that in mice with a low dosage. However, the BMD values in each group of KK-Ay diabetic mice were not significantly different. We demonstrate that cathepsin K expression is increased in KK-Ay diabetic mouse model. JTXK granule treatment inhibits osteoclastic bone resorption and promotes the new bone formation by decreasing cathepsin K activity and increasing IGF-1 and ALP levels. These changes may contribute to the increase of bone strength and thus reducing the risk of bone fractures. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 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

  17. Serum IGF-1, IGFBP-3 levels and circulating tumor cells (CTCs) in early breast cancer patients.

    PubMed

    Papadakis, Georgios Z; Mavroudis, Dimitrios; Georgoulias, Vasilios; Souglakos, John; Alegakis, Athanasios K; Samonis, George; Bagci, Ulas; Makrigiannakis, Antonis; Zoras, Odysseas

    2017-04-01

    Insulin-like growth factor (IGF)-axis is involved in human oncogenesis and metastasis development for various solid tumors including breast cancer. Aim of this study was to assess the association between IGF-1, IGF-binding protein-3 (IGFBP-3) serum levels and the presence of circulating tumor cells (CTCs) in the peripheral blood of women diagnosed with early breast cancer (EBC), before and after adjuvant chemotherapy. 171 patients with early-stage breast adenocarcinomas were retrospectively evaluated. Immunoradiometric (IRMA) assays were employed for the in-vitro determination of IGF-1 and IGFBP-3 serum levels in blood samples collected after surgical treatment and before initiation of adjuvant chemotherapy. CTCs' presence was assessed through detection of cytokeratin-19 (CK-19) mRNA transcripts using quantitative real time reverse transcription polymerase chain reaction (RT-PCR). IGF-1, IGFBP-3 serum levels were correlated with CTCs' presence before and after adjuvant chemotherapy as well as with tumor characteristics including tumor size, axillary lymph node status, oestrogen (ER)/progestorene (PR) and human epidermural growth factor receptor 2 (HER2) receptor status. Log-rank test was applied to investigate possible association between IGF-1, IGFBP-3 serum levels and disease-free interval (DFI) and overall survival (OS). Before initiation of adjuvant therapy IGF-1, IGFBP-3 serum levels were moderately associated (Spearman's rho=0.361, p<0.001) with each other, while presenting significant differences across age groups (all p values<0.05). IGF-1 serum levels did not correlate with the presence of CTCs before initiation (p=0.558) or after completion (p=0.474) of adjuvant chemotherapy. Similarly, IGFBP-3 serum levels did not show significant association with detectable CTCs either before (p=0.487) or after (p=0.134) completion of adjuvant chemotherapy. There was no statistically significant association between the clinical outcome of patients in terms of DFI, OS

  18. 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.

  19. 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.

  20. 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.

  1. Human monoclonal antibodies to the insulin-like growth factor 1 receptor inhibit receptor activation and tumor growth in preclinical studies.

    PubMed

    Runnels, Herbert A; Arbuckle, J Alan; Bailey, Karen S; Nicastro, Peter J; Sun, Duo; Pegg, Jodi A; Meyer, Debra M; Evans, Michelle; Bono, Christine P; Lie, Wen-Rong; Moffat, Mark A; Casperson, Gerald F; Lennard, Simon; Elvin, John; Vaughan, Tristan; Smith, Christine E; Morton, Phillip A

    2010-07-01

    The insulin-like growth factor type 1 (IGF-1) receptor contributes importantly to transformation and survival of tumor cells both in vitro and in vivo, and selective antagonists of the IGF-1 receptor (IGF-1R) activity represent an attractive experimental approach for human cancer therapy. Using a phage display library, we identified several high-affinity fully human monoclonal antibodies with inhibitory activity against both human and rodent IGF.1Rs. These candidate therapeutic antibodies recognized several distinct epitopes and effectively blocked ligand-mediated receptor signal transduction and cellular proliferation in vitro. They also induced IGF-1R downregulation and catabolism following antibody-mediated endocytosis. These antibodies exhibited activity against human, primate, and rodent IGF-1Rs, and dose-dependently inhibited the growth of established human tumors in nude mice. These fully human antibodies therefore have the potential to provide an effective anti-tumor biological therapy in the human clinical setting.

  2. 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.

  3. IGF-1 as a drug for preterm infants: a step-wise clinical development.

    PubMed

    Hellstrom, Ann; Ley, David; Hallberg, Boubou; Lofqvist, Chatarina; Hansen-Pupp, Ingrid; Ramenghi, Luca A; Borg, Jan; Smith, Lois E H; Hard, Anna-Lena

    2017-10-02

    Insulin-like growth factor 1 (IGF-1) is a mitogenic hormone involved in many processes such as growth, metabolism, angiogenesis and differentiation. After very preterm birth, energy demands increase while maternal supplies of nutrients and other factors are lost and the infant may become dependent on parenteral nutrition for weeks. Low postnatal IGF-1 concentrations in preterm infants are associated with poor weight gain, retinopathy of prematurity (ROP) and other morbidities. We will describe the process by which we aim to develop supplementation with recombinant human (rh) IGF-1 and its binding protein rhIGFBP-3 as a possible therapy to promote growth and maturation and reduce morbidities in extremely preterm infants. In order to calculate a dose of IGF-1 tolerated by neonates, a pharmacokinetic study of transfusion with fresh frozen plasma was performed, which provided a relatively low dose of IGF-1, (on average 1.4 μg/kg), that increased serum IGF-1 to levels close to those observed in fetuses and preterm infants of similar GAs. Thereafter, a Phase I 3 hours IV infusion of rhIGF-1/rhIGFBP-3 was conducted in 5 infants, followed by a Phase II study with four sections (A-D). In the Phase II, sections A-D studies, time on infusion increased and younger gestational ages were included. IV infusion increased IGF-1 but with short half-life (0.5h) implying a need for continuous infusion. In order to obtain in utero levels of IGF-I, the dose was increased from 100 to 250 μg/kg/24 h and the infusion was prolonged from 3 weeks postnatal age until a postmenstrual age of 29 weeks and 6 days. The purpose has been to ensure high-quality research into the development of a new drug for preterm infants. We hope that our work will help to establish a new standard for the testing of medications for preterm infants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

    MedlinePlus

    ... diagnose and monitor treatment of two rare conditions, acromegaly and gigantism . IGF-1 is a hormone that, ... gigantism or when an adult shows signs of acromegaly . When a GH-producing pituitary tumor is found, ...

  5. Childhood obesity and insulin resistance in a Yucatan mini-piglet model: putative roles of IGF-1 and muscle PPARs in adipose tissue activity and development.

    PubMed

    Sébert, S P; Lecannu, G; Kozlowski, F; Siliart, B; Bard, J M; Krempf, M; Champ, M M-J

    2005-03-01

    To explore metabolic and cellular modifications induced during childhood obesity, in a novel animal model of obese mini-piglets. A total of 10 four-month old Yucatan mini-pigs were followed from prepuberty to adulthood. Animals were divided into two groups. The first one had been overfed (OF) a western-type diet and the second one had been normally fed a control recommended human-type diet (NF). Plasma insulin-like growth factor 1 (IGF-1), insulin, leptin, nonesterified fatty acids, triglycerides (TGs) and glucose were determined at sexual maturity and at young adulthood. Quantitative gene expressions of peroxysome-proliferator-activated receptors (PPARs), glucose transporter 4, insulin receptor, IGF-1, leptin and interleukin-6 (IL-6) in skeletal muscle, adipose tissue and liver were also measured at both stages. Adult insulin sensitivity was measured via euglycaemic-hyperinsulinaemic clamps. Increased body weight in adult OF pigs was associated with increased body size and low insulin sensitivity. Sexually mature OF pigs had higher IGF-1 plasma concentrations than their lean littermates (P < 0.05). In the OF group, TGs and glucose were both decreased (P < 0.05). Muscle PPARgamma and alpha in OF pubescent pigs as compared to NF pigs were 11 times higher and 20 times lower, respectively (P < 0.01). Obesity and insulin resistance induced by overfeeding mini-pigs during development and puberty were not associated with the cluster of metabolic modifications frequently observed in their adult littermates. Increased IGF-1 concentrations and modifications of skeletal muscle PPAR (alpha and gamma) expressions may help the young obese pig to partially regulate its glycaemia and triglyceridaemia through an increase of fat mass, which maintains its high insulin sensitivity.

  6. Additive effect of diets and training on total insulin-like growth factor-1 (IGF-1) in rats.

    PubMed

    El Elj, N; Lac, G; Alya, B; Lasram, M; Zaouali, M; Tabka, Z; Kammoun, A; Gharbi, N; El Fezaa, S

    2010-09-01

    Although it is known that circulating levels of insulin-like growth factor-1 (IGF-1) are influenced by both physical exercise and dietary intake separately, there is little information regarding the additive effect of diets and training on IGF-1 regulation. To test this, we examined the combined effect of 30 days of two different diets (high-protein and high-carbohydrate) and exercise training on total IGF-1. The study was carried out with four groups of rats; the sedentary group with standard diet (SS) (control group), standard diet with exercise (SE), high-protein diet with exercise (PE) and high-carbohydrate diet with exercise (CE). Serum IGF-1, insulin, corticosterone were analyzed. IGF-1 concentrations were decreased by exercise training (p<0.001) and only with protein diet (p<0.05). Physical training, with and without diet, decreased body weight and food intake (p<0.01) and increased corticosterone levels (p<0.05). Carbohydrate diet did not cause major hormonal and metabolic alterations. The main result of this study was the decreased levels of IGF-1 in spite of high-protein diet, which is known to enhance IGF-1 secretion, and the little changes with carbohydrate diet. This may be related to the negative energy balance as a result of the catabolic state induced by exercise training and decreased calorie intake in protein diet. Thus, it can be concluded that the caloric restriction, regardless of dietary composition, decreased IGF-1 secretion. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  7. 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

  8. Targeting IGF-1R with ganitumab inhibits tumorigenesis and increases durability of response to androgen-deprivation therapy in VCaP prostate cancer xenografts

    PubMed Central

    Fahrenholtz, Cale D; Beltran, Pedro J; Burnstein, Kerry L

    2013-01-01

    Prostate cancer is the most commonly diagnosed malignancy in men. While tumors initially respond to androgen-deprivation therapy, the standard care for advanced or metastatic disease, tumors eventually recur as castration-resistant prostate cancer. Upregulation of the insulin-like growth factor receptor type 1 (IGF-1R) signaling axis drives growth and progression of prostate cancer by promoting proliferation, survival, and angiogenesis. Ganitumab (formerly AMG 479) is a fully human antibody that inhibits binding of IGF-1 and IGF-2 to IGF-1R. We evaluated the therapeutic value of ganitumab in several pre-clinical settings including androgen-dependent prostate cancer, castration-resistant prostate cancer, and in combination with androgen-deprivation therapy. Ganitumab inhibited IGF-1 induced phosphorylation of the downstream effector AKT and reduced proliferation of multiple androgen-dependent and castration-resistant human prostate cancer cell lines in vitro. Ganitumab inhibited androgen-dependent VCaP xenograft growth and increased tumor doubling time from 2.3±0.4 weeks to 6.4±0.4 weeks. Ganitumab blocked growth of castration-resistant VCaP xenografts for over 11.5 weeks of treatment. In contrast, ganitumab did not have appreciable effects on the castration-resistant CWR-22Rv1 xenograft model. Ganitumab was most potent against VCaP xenografts when combined with complete androgen-deprivation therapy (castration). Tumor volume was reduced by 72% after 4 weeks of treatment and growth suppression was maintained over 16 weeks of treatment. These data suggest that judicious use of ganitumab particularly in conjunction with androgen-deprivation therapy may be beneficial in the treatment of prostate cancer. PMID:23348048

  9. 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.

  10. GH and IGF1 levels are positively associated with musculotendinous collagen expression: experiments in acromegalic and GH deficiency patients.

    PubMed

    Doessing, Simon; Holm, Lars; Heinemeier, Katja M; Feldt-Rasmussen, Ulla; Schjerling, Peter; Qvortrup, Klaus; Larsen, Jytte O; Nielsen, Rie H; Flyvbjerg, Allan; Kjaer, Michael

    2010-12-01

    Disproportionate growth of musculoskeletal tissue is a major cause of morbidity in both acromegalic (ACRO) and GH-deficient (GHD) patients. GH/IGF1 is likely to play an important role in the regulation of tendon and muscle collagen. We hypothesized that the local production of collagen is associated with the level of GH/IGF1. As primary outcomes, collagen mRNA expression and collagen protein fractional synthesis rate (FSR) were determined locally in skeletal muscle and tendon in nine ACRO and nine GHD patients. Moreover, muscle myofibrillar protein synthesis and tendon collagen morphology were determined. Muscle collagen I and III mRNA expression was higher in ACRO patients versus GHD patients (P<0.05), whereas collagen protein FSR did not differ significantly between ACRO and GHD patients in muscle (P=0.21) and tendon (P=0.15). IGF1Ea and IGF1Ec mRNA expression in muscle was higher in ACRO patients versus GHD patients (P<0.01). Muscle IGF1Ea mRNA expression correlated positively with collagen I mRNA expression (P<0.01). Tendon collagen fibrillar area tended to be higher in GHD patients relative to ACRO patients (P=0.07). Thus, we observed a higher expression for collagen and IGF1 mRNA in local musculotendinous tissue in ACRO patients relative to GHD patients. Moreover, there was a tendency towards a higher collagen protein FSR and a smaller collagen fibril diameter in ACRO patients relative to GHD patients. The results indicate a collagen-stimulating role of local IGF1 in human connective tissue and add to the understanding of musculoskeletal pathology in patients with either high or low GH/IGF1 axis activity.

  11. Effectiveness and Safety of rhIGF-1 Therapy in Children: The European Increlex® Growth Forum Database Experience.

    PubMed

    Bang, Peter; Polak, Michel; Woelfle, Joachim; Houchard, Aude

    2015-01-01

    We report data from the EU Increlex® Growth Forum Database (IGFD) Registry, an ongoing, open-label, observational study monitoring clinical practice use of recombinant human insulin-like growth factor-1 (rhIGF-1) therapy in children. Safety and effectiveness data on rhIGF-1 treatment of 195 enrolled children with growth failure were collected from December 2008 to September 2013. Mean ± SD (95% CI) height velocity during first year of rhIGF-1 treatment was 6.9 ± 2.2 cm/year (6.5; 7.2) (n = 144); in prepubertal patients naïve to treatment, this was 7.3 ± 2.0 cm/year (6.8; 7.7) (n = 81). Female sex, younger age at start of rhIGF-1 therapy, and lower baseline height SDS predicted first-year change in height SDS. The most frequent targeted treatment-emergent adverse events (% patients) were hypoglycemia (17.6%, predictors: young age, diagnosis of Laron syndrome, but not rhIGF-1 dose), lipohypertrophy (10.6%), tonsillar hypertrophy (7.4%), injection site reactions (6.4%), and headache (5.9%). Sixty-one serious adverse events (37 related to rhIGF-1 therapy) were reported in 31 patients (16.5%). Safety and effectiveness data on use of rhIGF-1 in a 'real-world' setting were similar to those from controlled randomized trials. Severe growth phenotype and early start of rhIGF-1 improved height response and predicted risk of hypoglycemia. © 2015 S. Karger AG, Basel.

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

    PubMed

    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

    2015-03-01

    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. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  13. 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.

  14. Human Axonal Survival of Motor Neuron (a-SMN) Protein Stimulates Axon Growth, Cell Motility, C-C Motif Ligand 2 (CCL2), and Insulin-like Growth Factor-1 (IGF1) Production*

    PubMed Central

    Locatelli, Denise; Terao, Mineko; Fratelli, Maddalena; Zanetti, Adriana; Kurosaki, Mami; Lupi, Monica; Barzago, Maria Monica; Uggetti, Andrea; Capra, Silvia; D'Errico, Paolo; Battaglia, Giorgio S.; Garattini, Enrico

    2012-01-01

    Spinal muscular atrophy is a fatal genetic disease of motoneurons due to loss of full-length survival of motor neuron protein, the main product of the disease gene SMN1. Axonal SMN (a-SMN) is an alternatively spliced isoform of SMN1, generated by retention of intron 3. To study a-SMN function, we generated cellular clones for the expression of the protein in mouse motoneuron-like NSC34 cells. The model was instrumental in providing evidence that a-SMN decreases cell growth and plays an important role in the processes of axon growth and cellular motility. In our conditions, low levels of a-SMN expression were sufficient to trigger the observed biological effects, which were not modified by further increasing the amounts of the expressed protein. Differential transcriptome analysis led to the identification of novel a-SMN-regulated factors, i.e. the transcripts coding for the two chemokines, C-C motif ligands 2 and 7 (CCL2 and CCL7), as well as the neuronal and myotrophic factor, insulin-like growth factor-1 (IGF1). a-SMN-dependent induction of CCL2 and IGF1 mRNAs resulted in increased intracellular levels and secretion of the respective protein products. Induction of CCL2 contributes to the a-SMN effects, mediating part of the action on axon growth and random cell motility, as indicated by chemokine knockdown and re-addition studies. Our results shed new light on a-SMN function and the underlying molecular mechanisms. The data provide a rational framework to understand the role of a-SMN deficiency in the etiopathogenesis of spinal muscular atrophy. PMID:22669976

  15. 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

  16. IGF-1R inhibition enhances radiosensitivity and delays double-strand break repair by both non-homologous end-joining and homologous recombination.

    PubMed

    Chitnis, M M; Lodhia, K A; Aleksic, T; Gao, S; Protheroe, A S; Macaulay, V M

    2014-11-06

    Inhibition of type 1 insulin-like growth factor receptor (IGF-1R) enhances tumor cell sensitivity to ionizing radiation. It is not clear how this effect is mediated, nor whether this approach can be applied effectively in the clinic. We previously showed that IGF-1R depletion delays repair of radiation-induced DNA double-strand breaks (DSBs), unlikely to be explained entirely by reduction in homologous recombination (HR) repair. The current study tested the hypothesis that IGF-1R inhibition induces a repair defect that involves non-homologous end joining (NHEJ). IGF-1R inhibitor AZ12253801 blocked cell survival and radiosensitized IGF-1R-overexpressing murine fibroblasts but not isogenic IGF-1R-null cells, supporting specificity for IGF-1R. IGF-1R inhibition enhanced radiosensitivity in DU145, PC3 and 22Rv1 prostate cancer cells, comparable to effects of Ataxia Telangiectasia Mutated inhibition. AZ12253801-treated DU145 cells showed delayed resolution of γH2AX foci, apparent within 1 h of irradiation and persisting for 24 h. In contrast, IGF-1R inhibition did not influence radiosensitivity or γH2AX focus resolution in LNCaP-LN3 cells, suggesting that radiosensitization tracks with the ability of IGF-1R to influence DSB repair. To differentiate effects on repair from growth and cell-survival responses, we tested AZ12253801 in DU145 cells at sub-SF50 concentrations that had no early (⩽48 h) effects on cell cycle distribution or apoptosis induction. Irradiated cultures contained abnormal mitoses, and after 5 days IGF-1R-inhibited cells showed enhanced radiation-induced polyploidy and nuclear fragmentation, consistent with the consequences of entry into mitosis with incompletely repaired DNA. AZ12253801 radiosensitized DNA-dependent protein kinase (DNA-PK)-proficient but not DNA-PK-deficient glioblastoma cells, and did not radiosensitize DNA-PK-inhibited DU145 cells, suggesting that in the context of DSB repair, IGF-1R functions in the same pathway as DNA

  17. 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

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

    PubMed Central

    Mangiola, Annunziato; Vigo, Vera; Anile, Carmelo; De Bonis, Pasquale; 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

  19. 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

  20. IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats.

    PubMed

    Zhao, Tian-Yu; Su, Li-Ping; Ma, Chun-Ye; Zhai, Xiao-Han; Duan, Zhi-Jun; Zhu, Ying; Zhao, Gang; Li, Chun-Yan; Wang, Li-Xia; Yang, Dong

    2015-07-08

    Intestinal barrier dysfunction is not only the consequence of liver cirrhosis, but also an active participant in the development of liver cirrhosis. Previous studies showed that external administration of insulin-like growth factor 1 (IGF-1) improved intestinal barrier function in liver cirrhosis. However, the mechanism of IGF-1 on intestinal barrier in liver cirrhosis is not fully elucidated. The present study aims to investigate the mechanisms of IGF-1 improving intestinal barrier function via regulating tight junctions in intestines. We used carbon tetrachloride induced liver cirrhotic rats to investigate the effect of IGF-1 on intestinal claudin-1 and occludin expressions, serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, severity of liver fibrosis, portal pressures, enterocytic apoptosis and lipopolysaccharides (LPS) levels in portal vein. The changes of IGF-1 in serum during the development of rat liver cirrhosis were also evaluated. Additionally, we assessed the effect of IGF-1 on claudin-1 and occludin expressions, changes of transepithelial electrical resistance (TEER) and apoptosis in Caco-2 cells to confirm in vivo findings. Serum IGF-1 levels were decreased in the development of rat liver cirrhosis, and external administration of IGF-1 restored serum IGF-1 levels. External administration of IGF-1 reduced serum ALT and AST levels, severity of liver fibrosis, LPS levels in portal vein, enterocytic apoptosis and portal pressure in cirrhotic rats. External administration of IGF-1 increased the expressions of claudin-1 and occludin in enterocytes, and attenuated tight junction dysfunction in intestines of cirrhotic rats. LPS decreased TEER in Caco-2 cell monolayer. LPS also decreased claudin-1 and occludin expressions and increased apoptosis in Caco-2 cells. Furthermore, IGF-1 attenuated the effect of LPS on TEER, claudin-1 expression, occludin expression and apoptosis in Caco-2 cells. Tight junction dysfunction develops during the

  1. 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.

  2. 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

  3. IGF-1 promotes G1/S cell cycle progression through bidirectional regulation of cyclins and CDK inhibitors via the PI3K/Akt pathway in developing rat cerebral cortex

    PubMed Central

    Mairet-Coello, Georges; Tury, Anna; DiCicco-Bloom, Emanuel

    2011-01-01

    While survival promoting effects of insulin-like growth factor-1 (IGF-1) during neurogenesis are well characterized, mitogenic effects remain less well substantiated. Here, we characterize cell cycle regulators and signaling pathways underlying IGF-1 effects on embryonic cortical precursor proliferation in vitro and in vivo. In vitro, IGF-1 stimulated cell cycle progression and increased cell number without promoting cell survival. IGF-1 induced rapid increases in cyclin D1 and D3 protein levels at 4h and cyclin E at 8h. Moreover, p27KIP1 and p57KIP2 expression were reduced, suggesting downregulation of negative regulators contributes to mitogenesis. Further, the PI3K/Akt pathway specifically underlies IGF-1 activity, as blocking this pathway, but not MEK/ERK, prevented mitogenesis. To determine whether mechanisms defined in culture relate to corticogenesis in vivo, we performed transuterine intracerebroventricular injections. While blockade of endogenous factor with anti-IGF-1 antibody decreased DNA synthesis, IGF-1 injection stimulated DNA synthesis and increased the number of S-phase cells in the VZ. IGF-1 treatment increased phospho-Akt 4 fold at 30 min, cyclins D1 and E by 6h, and decreased p27KIP1 and p57KIP2 expression. Moreover, blockade of the PI3K/Akt pathway in vivo decreased DNA synthesis and cyclin E, increased p27KIP1 and p57KIP2 expression, and prevented IGF-1 induced cyclin E mRNA upregulation. Finally, IGF-1 injection in embryos increased P10 brain DNA content by 28%, suggesting a role for IGF-1 in brain growth control. These results demonstrate a mitogenic role for IGF-1 which tightly controls both positive and negative cell cycle regulators, and indicate that the PI3K/Akt pathway mediates IGF-1 mitogenic signaling during corticogenesis. PMID:19158303

  4. Intrauterine growth restriction perturbs nucleosome depletion at a growth hormone-responsive element in the mouse IGF-1 gene.

    PubMed

    McKnight, Robert A; Yost, Christian C; Yu, Xing; Wiedmeier, Julia E; Callaway, Christopher W; Brown, Ashley S; Lane, Robert H; Fung, Camille M

    2015-12-01

    Intrauterine growth restriction (IUGR) is a common human pregnancy complication. IUGR offspring carry significant postnatal risk for early-onset metabolic syndrome, which is associated with persistent reduction in IGF-1 protein expression. We have previously shown that preadolescent IUGR male mice have decreased hepatic IGF-1 mRNA and circulating IGF-1 protein at postnatal day 21, the age when growth hormone (GH) normally upregulates hepatic IGF-1 expression. Here we studied nucleosome occupancy and CpG methylation at a putative growth hormone-responsive element in intron 2 (in2GHRE) of the hepatic IGF-1 gene in normal, sham-operated, and IUGR mice. Nucleosome occupancy and CpG methylation were determined in embryonic stem cells (ESCs) and in liver at postnatal days 14, 21, and 42. For CpG methylation, additional time points out to 2 yr were analyzed. We confirmed the putative mouse in2GHRE was GH-responsive, and in normal mice, a single nucleosome was displaced from the hepatic in2GHRE by postnatal day 21, which exposed two STAT5b DNA binding sites. Nucleosome displacement correlated with developmentally programmed CpG demethylation. Finally, IUGR significantly altered the nucleosome-depleted region (NDR) at the in2GHRE of IGF-1 on postnatal day 21, with either complete absence of the NDR or with a shifted NDR exposing only one of two STAT5b DNA binding sites. An NDR shift was also seen in offspring of sham-operated mothers. We conclude that prenatal insult such as IUGR or anesthesia/surgery could perturb the proper formation of a well-positioned NDR at the mouse hepatic IGF-1 in2GHRE necessary for transitioning to an open chromatin state. Copyright © 2015 the American Physiological Society.

  5. 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.

  6. 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.

  7. Overexpression of IGF-1 attenuates skeletal muscle damage and accelerates muscle regeneration and functional recovery after disuse

    PubMed Central

    Ye, Fan; Mathur, Sunita; Liu, Min; Borst, Stephen E.; Walter, Glenn A.; Sweeney, H. Lee; Vandenborne, Krista

    2014-01-01

    Skeletal muscle is a highly dynamic tissue that responds to endogenous and external stimuli, including alterations in mechanical loading and growth factors. In particular, the antigravity soleus muscle experiences significant muscle atrophy during disuse and extensive muscle damage upon reloading. Since insulin-like growth factor-1 (IGF-1) has been implicated as a central regulator of muscle repair and modulation of muscle size, we examined the effect of viral mediated overexpression of IGF-1 on the soleus muscle following hindlimb cast immobilization and upon reloading. Recombinant IGF-1 cDNA virus was injected into one of the posterior hindlimbs of the mice, while the contralateral limb was injected with saline (control). At 20 weeks of age, both hindlimbs were immobilized for two weeks to induce muscle atrophy in the soleus and ankle plantar flexor muscle group. Subsequently, the mice were allowed to reambulate and muscle damage and recovery was monitored over a period of 2 to 21 days. The primary finding of this study was that IGF-1 overexpression attenuated reloading-induced muscle damage in the soleus muscle, and accelerated muscle regeneration and force recovery. Muscle T2 assessed by MRI, a nonspecific marker of muscle damage, was significantly lower in IGF-1 injected, compared to contralateral soleus muscles at 2 and 5 days reambulation (P<0.05). The reduced prevalence of muscle damage in IGF-1 injected soleus muscles was confirmed on histology, with a lower fraction area of abnormal muscle tissue in IGF-I injected muscles at 2 days reambulation (33.2±3.3%vs 54.1±3.6%, P<0.05). Evidence of the effect of IGF-1 on muscle regeneration included timely increases in the number of central nuclei (21% at 5 days reambulation), paired-box transcription factor 7 (36% at 5 days), embryonic myosin (37% at 10 days), and elevated MyoD mRNA (7-fold at 2 days) in IGF-1 injected limbs (P<0.05). These findings demonstrate a potential role of IGF-1 in protecting unloaded

  8. 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

  9. 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

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

    PubMed

    Bitar, Milad S; Al-Mulla, Fahd

    2012-05-01

    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 pathophysiologically relevant

  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. 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

  13. 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.

  14. CCAAT-enhancer binding protein (C/EBP) β regulates insulin-like growth factor (IGF) 1 expression in porcine liver during prenatal and postnatal development.

    PubMed

    Tang, Yiting; Xiong, Kai; Shen, Ming; Mu, Yulian; Li, Kui; Liu, Honglin

    2015-03-01

    IGF1 expression regulation attracts numerous interests because of its important role during mammalian growth and development. Domestic pig can be used as a valuable animal model to investigate human development since they share the high similarity in general physiology and metabolism. In this study, we examined the expression pattern of IGF1 and found it associated with liver C/EBP β expression pattern in porcine liver during embryonic and postnatal development. Both IGF1 and C/EBP β expression in liver maintained at low levels before birth and increased after birth. Correspondingly, C/EBP β demonstrated high binding activity to two sites at IGF1 promoter region in liver after birth. Additionally, IGF1 expression can be activated by C/EBP β overexpression in porcine primary hepatocytes. These results indicated that C/EBP β can activate IGF1 expression after birth by binding to IGF1 promoter. Our study may contribute to a better understanding of mammalian development and bring a novel anti-aging pathway in human.

  15. 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.

  16. 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.

  17. 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.

  18. After Myocardial Ischemia-Reperfusion, miR-29a, and Let7 Could Affect Apoptosis through Regulating IGF-1

    PubMed Central

    Wang, Lei; Niu, Xuehong; Hu, Jihua; Xing, Haijian; Sun, Min; Wang, Juanli; Jian, Qiang; Yang, Hua

    2015-01-01

    Cardiovascular and cerebrovascular ischemic disease is a large class of diseases that is harmful to human health. The primary treatment for the ischemic disease is to recover the blood perfusion and relieve the tissue hypoxia and the shortage of the nutrients in the supply of nutrients. In recent years, investigations found that IGF-1 has a protective effect on cardiovascular disease, especially in myocardial ischemia-reperfusion injury. Investigation into molecular mechanism of ischemia-reperfusion injury may offer potential targets for the development of novel diagnostic strategies. In this study we defined IGF-1 was differentially expressed in the I/R model of the Mus musculus and IGF-1 was the target gene of miR-29a and Let7f. After ischemia-reperfusion, the expression of miR-29a and Let7f increased, while the expression of IGF-1 decreased significantly in the animal model assay. Further studies have found that IGF-1 could inhibit cell apoptosis signaling pathway, thus protecting the reperfusion injury. These results provide new understanding of ischemia-reperfusion injury, with the hope of offering theoretical support for future therapeutic studies. PMID:26844226

  19. 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

  20. MicroRNA-214 Reduces Insulin-like Growth Factor-1 (IGF-1) Receptor Expression and Downstream mTORC1 Signaling in Renal Carcinoma Cells*

    PubMed Central

    Das, Falguni; Dey, Nirmalya; Bera, Amit; Kasinath, Balakuntalam S.; Ghosh-Choudhury, Nandini; Choudhury, Goutam Ghosh

    2016-01-01

    Elevated IGF-1/insulin-like growth factor-1 receptor (IGF-1R) autocrine/paracrine signaling in patients with renal cell carcinoma is associated with poor prognosis of the disease independent of their von Hippel-Lindau (VHL) status. Increased expression of IGF-1R in renal cancer cells correlates with their potency of tumor development and progression. The mechanism by which expression of IGF-1R is increased in renal carcinoma is not known. We report that VHL-deficient and VHL-positive renal cancer cells possess significantly decreased levels of mature, pre-, and pri-miR-214 than normal proximal tubular epithelial cells. We identified an miR-214 recognition element in the 3′UTR of IGF-1R mRNA and confirmed its responsiveness to miR-214. Overexpression of miR-214 decreased the IGF-1R protein levels, resulting in the inhibition of Akt kinase activity in both types of renal cancer cells. IGF-1 provoked phosphorylation and inactivation of PRAS40 in an Akt-dependent manner, leading to the activation of mTORC1 signal transduction to increase phosphorylation of S6 kinase and 4EBP-1. Phosphorylation-deficient mutants of PRAS40 and 4EBP-1 significantly inhibited IGF-1R-driven proliferation of renal cancer cells. Expression of miR-214 suppressed IGF-1R-induced phosphorylation of PRAS40, S6 kinase, and 4EBP-1, indicating inhibition of mTORC1 activity. Finally, miR-214 significantly blocked IGF-1R-forced renal cancer cell proliferation, which was reversed by expression of 3′UTR-less IGF-1R and constitutively active mTORC1. Together, our results identify a reciprocal regulation of IGF-1R levels and miR-214 expression in renal cancer cells independent of VHL status. Our data provide evidence for a novel mechanism for IGF-1R-driven renal cancer cell proliferation involving miR-214 and mTORC1. PMID:27226530

  1. Follicular fluid insulin like growth factor-1 (FF IGF-1) is a biochemical marker of embryo quality and implantation rates in in vitro fertilization cycles.

    PubMed

    Mehta, Bindu N; Chimote, Natachandra M; Chimote, Meena N; Chimote, Nishad N; Nath, Nirmalendu M

    2013-04-01

    Insulin-like growth factor-1 (IGF-1) has been reported to play a role in human follicular and embryonic development. However, earlier studies carried out mostly in animal models or in culture mediums supplemented with IGF-1 have been unable to directly link IGF-1 with embryo quality. Results correlating IGF-1 with pregnancy outcome have also been ambiguous so far. The aim of this study is to find if in situ follicular-fluid level of IGF-1 is predictive of embryo quality and implantation rates in in vitro fertilization (IVF) cycles. Prospective study involving 120 cycles of conventional IVF-embryo transfer in infertile women. IGF-1 concentrations were estimated in pooled follicular-fluid on the day of oocyte-pickup. Embryo quality was assessed daily at different developmental stages. Cycles were sorted into low and high follicular fluid insulin-like growth factor-1 (FF IGF-1) groups according to the median value of measurement. Embryo quality, clinical pregnancy and implantation rate were the main outcome measures. Graph-pad Prism 5 statistical package. FF IGF-1 correlates with embryo quality (Pearson r = 0.3894, r (2) = 0.1516, P > 0.0001) and clinical pregnancy (Pearson r = 0.5972, r (2) = 0.36, P > 0.0001). High FF IGF-1 group shows significantly higher rates of fertilization, cleavage, blastocyst formation and top grade embryos compared with low FF IGF-1 group. Clinical pregnancy rates (38.33 vs. 20%, P = 0.0272) and embryo implantation rates (21.6 vs. 10.32%, P = 0.0152) are also significantly higher in the high versus low FF IGF-1 group. Threshold value of FF IGF-1 for clinical pregnancy is <58.50 ng/mg protein (receiver operating characteristics AUC : 0.85 ± 0.03, 95% CI: 0.78-0.91). FF IGF-1 is a plausible biochemical marker of embryo quality and implantation rate and correlates with clinical pregnancy rates in conventional IVF cycles.

  2. Insulin-like growth factor-1 (IGF-1) enhances the osteogenic activity of bone morphogenetic protein-6 (BMP-6) in vitro and in vivo, and together have a stronger osteogenic effect than when IGF-1 is combined with BMP-2.

    PubMed

    Rico-Llanos, Gustavo A; Becerra, Jose; Visser, Rick

    2017-07-01

    Bone morphogenetic protein-2 (BMP-2) is widely used in orthopedic surgery and bone tissue engineering because of its strong osteogenic activity. However, BMP-2 treatments have several drawbacks and many groups are actively exploring alternatives. Since BMP-6 has been demonstrated to be more osteoinductive, its use, either alone or together with other growth factors, might be an interesting option. In this work, we have compared the effect of BMP-2, BMP-6, or insulin-like growth factor-1 (IGF-1), either alone or in combination. Murine preosteoblasts were treated with 15 nM IGF-1 and/or 6 nM BMP-2 or -6 and the expression of osteogenic marker genes, proliferation, and alkaline phosphatase (ALP) activity in vitro were analyzed. The results showed that IGF-1 greatly enhanced the BMP-induced osteogenic differentiation of these cells in general and that the ALP activity in the cultures was higher when the combination was made with BMP-6 than with BMP-2. Furthermore, we tested the osteogenic potential of these treatments in vivo by loading 25 pmoles of IGF-1 and/or 10 pmoles of BMP-2 or -6 onto absorbable collagen sponges and implanting them into an ectopic bone formation model in rats. This study revealed that only BMP-6 was able to induce bone formation at the used dose and that the addition of IGF-1 contributed to an increase of the mineralization in the implants. Hence, the combination of BMP-6 with IGF-1 might be a better alternative than BMP-2 for orthopedic surgery or bone tissue engineering approaches. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1867-1875, 2017. © 2017 Wiley Periodicals, Inc.

  3. 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

  4. The anti-apoptotic effect of IGF-1 on tissue resident stem cells is mediated via PI3-kinase dependent secreted frizzled related protein 2 (Sfrp2) release

    SciTech Connect

    Gehmert, Sebastian; Sadat, Sanga; Song Yaohua; Yan Yasheng; Alt, Eckhard

    2008-07-11

    Previous studies suggest that IGF-1 may be used as an adjuvant to stem cell transfer in order to improve cell engraftment in ischemic tissue. In the current study, we investigated the effect of IGF-1 on serum deprivation and hypoxia induced stem cell apoptosis and the possible mechanisms involved. Exposure of adipose tissue derived stem cells (ASCs) to serum deprivation and hypoxia resulted in significant apoptosis in ASC which is partially prevented by IGF-1. IGF-1's anti-apoptotic effect was abolished in ASCs transfected with Sfrp2 siRNA but not by the control siRNA. Using Western blot analysis, we demonstrated that serum deprivation and hypoxia reduced the expression of nuclear {beta}-catenin, which is reversed by IGF-1. IGF-1's effect on {beta}-catenin expression was abolished by the presence of PI3-kinase inhibitor LY294002 or in ASCs transfected with Sfrp2 siRNA. These results suggest that IGF-1, through the release of the Sfrp2, contributes to cell survival by stabilizing {beta}-catenin.

  5. 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

  6. 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

  7. 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

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

    PubMed

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

    2011-04-18

    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 2h. 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 4h before being returned to their dams. Two doses of 50 μg recombinant human IGF-1 were administered intranasally at a 1h interval starting at 0, 2 or 4h 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 2h 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 6h 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.

  9. Comparison of a conventional immunoassay (ELISA) with a surface plasmon resonance-based biosensor for IGF-1 detection in cows' milk.

    PubMed

    Guidi, A; Laricchia-Robbio, L; Gianfaldoni, D; Revoltella, R; Del Bono, G

    2001-12-01

    Recombinant bovine somatotropin (rBST) treatment is adopted in dairy cows to augment milk yield. Previous studies showed that insulin-like growth factor-1 (IGF-1) is present in milk from cows treated with rBST. Since IGF-1 is a suspected carcinogen, its presence in milk for human consumption is potentially a health hazard. Therefore rBST use, still authorized in the United States, has been revoked in Canada and is under evaluation in the EU. The rising attention on IGF-1 presence in alimentary milk focused the necessity to develop specific, sensitive and rapid IGF-1 detection systems. We have developed a solid phase enzyme-linked immunoassay (ELISA) and also an automated surface plasmon resonance-based biosensor system (BIA-technology) for evaluating IGF-1 in fresh cow's milk. Hyperimmune polyclonal anti-IGF-1 antibodies were characterized with respect to their specific binding capacity to IGF-1. The results obtained with these two methods have been compared. This study shows the potential usefulness of the biosensor technology for biomolecular interaction analysis. The features of this technology (fully automated, measures in real time, sharpened yes/no response) offer several advantages compared to ELISA in the detection of compounds in fresh cows' milk (MURST 40%; CNR P.F. MADESS 2).

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  15. 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.

  16. 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.

  17. MicroRNA-122 confers sorafenib resistance to hepatocellular carcinoma cells by targeting IGF-1R to regulate RAS/RAF/ERK signaling pathways.

    PubMed

    Xu, Yanmin; Huang, Ji; Ma, Leina; Shan, Juanjuan; Shen, Junjie; Yang, Zhi; Liu, Limei; Luo, Yongli; Yao, Chao; Qian, Cheng

    2016-02-28

    Sorafenib is the first-line treatment for advanced hepatocellular carcinoma (HCC), but the clinical response to sorafenib is seriously limited by drug resistance. In this study, we investigated the molecular mechanisms of sorafenib resistance in HCC cells. Our miRNA microarray data indicate that liver-specific miR-122 expression was significantly reduced in sorafenib-resistant cells. Overexpression of miR-122 made drug-tolerant cells sensitive to sorafenib and induced apoptosis. Insulin-like growth factor 1 receptor (IGF-1R) was validated as a target of miR-122 and was repressed by this miRNA. miR-122-induced apoptosis was repressed by the IGF-1R activator IGFI or IGFII. Conversely, the IGF-1R inhibitor PPP or NVP-AEW541 in combination with sorafenib significantly induced cell apoptosis and disrupted tolerance to drugs in vitro. These results indicated that activation of IGF-1R by ectopic down-regulation of miR-122 counteracted the effects of sorafenib-induced apoptosis, thus conferring sorafenib resistance. Further study revealed that activation of IGF-1R by miR-122 down-regulation contributed to activation of RAS/RAF/ERK signaling, which was associated with drug resistance. Our data imply that an intimate correlation between miR-122 and IGF-1R abnormal expression is a critical determinant of sorafenib tolerance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. 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.

  19. The energy sensing LKB1-AMPKα1 pathway regulates IGF1 secretion and consequent activation of the IGF1R-PKB pathway in primary hepatocytes.

    PubMed

    Chen, Liang; Chen, Qiaoli; Rong, Ping; Wang, Hong Yu; Chen, Shuai

    2017-07-01

    The insulin-like growth factor 1 (IGF1) pathway has been linked with various diseases including diabetes, cancer and aging. In contrast to the well-established regulatory mechanisms controlling IGF1 expression, molecular mechanisms regulating its secretion are not fully understood. The AMP-activated protein kinase (AMPK) is a key energy sensor, and cumulative evidence shows that it is an attractive therapeutic target for treatment of diabetes, cancer and aging. Here we found that deficiency of AMPK promoted IGF1 secretion in mouse primary hepatocytes. Furthermore, we found that AMPKα1 but not AMPKα2 was involved in regulation of IGF1 secretion in mouse primary hepatocytes. Knockout of AMPK caused activation of the IGF1 receptor (IGF1R)-protein kinase B (PKB; also known as Akt) pathway in hepatocytes, which was mediated by hypersecretion of IGF1. Upstream of AMPK, liver kinase B1 (LKB1) was responsible for AMPK-dependent suppression of IGF1 secretion in hepatocytes. Collectively, these findings demonstrate that the energy-sensing LKB1-AMPK pathway regulates IGF1 secretion in mouse primary hepatocytes, which in turn regulates activation of the IGF1R-PKB pathway. © 2017 Federation of European Biochemical Societies.

  20. Activation of Akt by Advanced Glycation End Products (AGEs): Involvement of IGF-1 Receptor and Caveolin-1

    PubMed Central

    Yang, Su-Jung; Chen, Chen-Yu; Chang, Geen-Dong; Wen, Hui-Chin; Chen, Ching-Yu; Chang, Shi-Chuan; Liao, Jyh-Fei; Chang, Chung-Ho

    2013-01-01

    Diabetes is characterized by chronic hyperglycemia, which in turn facilitates the formation of advanced glycation end products (AGEs). AGEs activate signaling proteins such as Src, Akt and ERK1/2. However, the mechanisms by which AGEs activate these kinases remain unclear. We examined the effect of AGEs on Akt activation in 3T3-L1 preadipocytes. Addition of AGEs to 3T3-L1 cells activated Akt in a dose- and time-dependent manner. The AGEs-stimulated Akt activation was blocked by a PI3-kinase inhibitor LY 294002, Src inhibitor PP2, an antioxidant NAC, superoxide scavenger Tiron, or nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase inhibitor DPI, suggesting the involvement of Src and NAD(P)H oxidase in the activation of PI3-kinase-Akt pathway by AGEs. AGEs-stimulated Src tyrosine phosphorylation was inhibited by NAC, suggesting that Src is downstream of NAD(P)H oxidase. The AGEs-stimulated Akt activity was sensitive to Insulin-like growth factor 1 receptor (IGF-1R) kinase inhibitor AG1024. Furthermore, AGEs induced phosphorylation of IGF-1 receptorβsubunit (IGF-1Rβ) on Tyr1135/1136, which was sensitive to PP2, indicating that AGEs stimulate Akt activity by transactivating IGF-1 receptor. In addition, the AGEs-stimulated Akt activation was attenuated by β-methylcyclodextrin that abolishes the structure of caveolae, and by lowering caveolin-1 (Cav-1) levels with siRNAs. Furthermore, addition of AGEs enhanced the interaction of phospho-Cav-1 with IGF-1Rβ and transfection of 3T3-L1 cells with Cav-1 Y14F mutants inhibited the activation of Akt by AGEs. These results suggest that AGEs activate NAD(P)H oxidase and Src which in turn phosphorylates IGF-1 receptor and Cav-1 leading to activation of IGF-1 receptor and the downstream Akt in 3T3-L1 cells. AGEs treatment promoted the differentiation of 3T3-L1 preadipocytes and addition of AG1024, LY 294002 or Akt inhibitor attenuated the promoting effect of AGEs on adipogenesis, suggesting that IGF-1 receptor, PI3

  1. Hepatic JAK2 protects against atherosclerosis through circulating IGF-1

    PubMed Central

    Sivasubramaniyam, Tharini; Schroer, Stephanie A.; Li, Angela; Luk, Cynthia T.; Shi, Sally Yu; Besla, Rickvinder; Metherel, Adam H.; Kitson, Alex P.; Brunt, Jara J.; Lopes, Joshua; Wagner, Kay-Uwe; Bazinet, Richard P.; Bendeck, Michelle P.; Robbins, Clinton S.

    2017-01-01

    Atherosclerosis is considered both a metabolic and inflammatory disease; however, the specific tissue and signaling molecules that instigate and propagate this disease remain unclear. The liver is a central site of inflammation and lipid metabolism that is critical for atherosclerosis, and JAK2 is a key mediator of inflammation and, more recently, of hepatic lipid metabolism. However, precise effects of hepatic Jak2 on atherosclerosis remain unknown. We show here that hepatic Jak2 deficiency in atherosclerosis-prone mouse models exhibited accelerated atherosclerosis with increased plaque macrophages and decreased plaque smooth muscle cell content. JAK2’s essential role in growth hormone signalling in liver that resulted in reduced IGF-1 with hepatic Jak2 deficiency played a causal role in exacerbating atherosclerosis. As such, restoring IGF-1 either pharmacologically or genetically attenuated atherosclerotic burden. Together, our data show hepatic Jak2 to play a protective role in atherogenesis through actions mediated by circulating IGF-1 and, to our knowledge, provide a novel liver-centric mechanism in atheroprotection. PMID:28724798

  2. IGF1R Variants Associated with Isolated Single Suture Craniosynostosis

    PubMed Central

    Cunningham, Michael L.; Horst, Jeremy A.; Rieder, Mark J.; Hing, Anne V.; Stanaway, Ian B.; Park, Sarah S.; Samudrala, Ram; Speltz, Matthew L.

    2010-01-01

    The genetic contribution to the pathogenesis of isolated single suture craniosynostosis is poorly understood. The role of mutations in genes known to be associated with syndromic synostosis appears to be limited. We present our findings of a candidate gene resequencing approach to identify rare variants associated with the most common forms of isolated craniosynostosis. Resequencing of the coding regions, splice junction sites, and 5′ and 3′ untranslated regions of 27 candidate genes in 186 cases of isolated nonsyndromic single suture synostosis revealed three novel and two rare sequence variants (R406H, R595H, N857S, P190S, M446V) in insulin-like growth factor I receptor (IGF1R) that are enriched relative to control samples. Mapping the resultant amino acid changes to the modeled homodimer protein structure suggests a structural basis for segregation between these and other disease-associated mutations found in IGF1R. These data suggest that IGF1R mutations may contribute to the risk and in some cases cause single suture craniosynostosis. PMID:21204214

  3. Novel functional polymorphism in IGF-1 gene associated with multiple sclerosis: A new insight to MS.

    PubMed

    Shahbazi, Majid; Abdolmohammadi, Reza; Ebadi, Hamid; Farazmandfar, Touraj

    2017-04-01

    Interactions between several genes and environment may play a role in susceptibility to multiple sclerosis (MS). The IGF-1 plays a key role in proliferation, maintenance and survival of nerve cells. Therefore, we hypothesized that IGF-1 may be a target for prediction and control MS. We aimed to analysis IGF-1 gene promoter sequence, to investigate the effect of the single nucleotide variants on IGF-1 expression and its association with MS. We enrolled 339 MS patients and 431 healthy controls. A specific region in IGF-1 gene promoter was investigated by SSCP analysis. All samples were genotyped by SSP-PCR. In-vitro and in-vivo IGF-1 production was measured by ELISA assay. IGF-1 expression in PBMCs was measured using real-time PCR. We identified a T to C single nucleotide substitution at position -1089 and a C to T at position -383 from transcription start site in the IGF-1 gene promoter. There was a significant association between MS and genotypes IGF-1(-383) C/T (p=0.001) and IGF-1(-383) C/C (p<0.001). There was also a significant association between IGF-1(-383) allele C and MS (p=0.001). In-vitro and in-vivo IGF-1 level showed that IGF-1 production in samples with genotype IGF-1(-383) C/C significantly was less than T/T (p=0.004) but not T/C (p=0.220). According to IGF-1 roles in CNS and our results, this study suggests that low IGF-1 level may be associated with susceptibility to MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Polymorphism of Insulin-like Growth Factor 1 Gene (IGF1/TasI, IGF1/SnaBI, IGF1/RsaI) and the Association with Daily Gain of Pesisir Cattle Local Breed from West Sumatera, Indonesia.

    PubMed

    Yurnalis; Arnim; Putra, Dino Eka

    2017-01-01

    The insulin-like growth factor 1 gene (IGF1) is a candidate gene for marker-assisted selection strategies. Two single nucleotide polymorphism of IGF1 gene namely IGF1/SnaBI and IGF1/TasI has been reported to be associated with production traits in several cattle breeds. One single nucleotide polymorphism in exon 4 namely IGF1/Rsa1 has a significant influence (p<0.01) on birth weight, weaning weight and average daily gain of Bali cattle. The objective of this study was to determine the IGF1/SnaBI, IGF1/TasI and IGF1/RsaI polymorphisms and their associations with average daily gain in Pesisir cattle local breed from west Sumatera Indonesia. The isolation of DNA from 183 blood sample was performed using DNA extraction kit (Promega DNA purification kit) following the manufacture procedure. The amplification of IGF1 fragment was done by master mix from Thermo Scientific. In the case of the IGF1/SnaBI polymorphism, three genotypes were observed, frequencies were 0.011, 0.011 and 0.978 for AA, AB and BB, respectively. This gives frequencies of 0.064 and 0.9836 for A and B alleles. For IGF1-TasI locus showed that AA genotype occurred with a frequency of 0.978, AC with 0.011 and CC with 0.011 with frequency for allele A and C were 0.9836 and 0.0164, respectively. In the case IGF1/RsaI polymorphism produces only TT and CT genotype with frequency 0.027 and 0.973 respectively and frequency of T and C allele were 0.5137 and 0.4863, respectively. Among these 3 polymorphism only IGF1/RsaI was associated with average daily gain, Thus this polymorphism could be a potential for improving body weight in Pesisir cattle. Association study for IGF1/SnaBI and IGF1/TasI were strongly limited by low frequency of one allele.

  5. Polymorphisms in the IGF1 and IGF1R genes and children born small for gestational age: results of large population studies.

    PubMed

    Ester, W A; Hokken-Koelega, A C S

    2008-06-01

    Small for gestational age (SGA) is the term used to describe a group of children born with a birth weight and/or birth length below the normal range of a reference population, corrected for their gestational age. Although animal models have shown that insulin-like growth factor 1 (IGF1) and insulin-like growth factor 1 receptor (IGF1R) genes are important candidates for reduced pre- and postnatal growth, only limited case reports have been published describing mutations. This might suggest that IGF1 and IGF1R are such crucial growth factors that only common genetic polymorphisms are allowed to survive. Common IGF1 and IGF1R gene polymorphisms, such as single nucleotide polymorphisms and variable number of tandem repeats, have been investigated with conflicting results with respect to SGA-related outcomes. The exact contribution of these polymorphisms to clinical practice remains to be elucidated.

  6. 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

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

    PubMed

    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.

  8. The effects of different doses of IGF-1 on cartilage and subchondral bone during the repair of full-thickness articular cartilage defects in rabbits.

    PubMed

    Zhang, Z; Li, L; Yang, W; Cao, Y; Shi, Y; Li, X; Zhang, Q

    2017-02-01

    To investigate the effects of different doses of insulin-like growth factor 1 (IGF-1) on the cartilage layer and subchondral bone (SB) during repair of full-thickness articular cartilage (AC) defects. IGF-1-loaded collagen membrane was implanted into full-thickness AC defects in rabbits. The effects of two different doses of IGF-1 on cartilage layer and SB adjacent to the defect, the cartilage structure, formation and integration, and the new SB formation were evaluated at the 1st, 4th and 8th week postoperation. Meanwhile, after 1 week treatment, the relative mRNA expressions in tissues adjacent to the defect, including cartilage and SB were determined by quantitative real-time RT-PCR (qRT-PCR), respectively. Different doses of IGF-1 induced different gene expression profiles in tissues adjacent to the defect and resulted in different repair outcomes. Particularly, at high dose IGF-1 aided cell survival, regulated the gene expressions in cartilage layer adjacent defect and altered ECM composition more effectively, improved the formation and integrity of neo-cartilage. While, at low dose IGF-1 regulated the gene expressions in SB more efficaciously and subsequently promoted the SB remodeling and reconstruction. Different doses of IGF-1 induced different responses of cartilage or SB during the repair of full-thickness AC defects. Particularly, high dose of IGF-1 was more beneficial to the neo-cartilage formation and integration, while low dose of it was more effective for the SB formation. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Impaired thermogenesis and adipose tissue development in mice with fat-specific disruption of insulin and IGF-1 signalling.

    PubMed

    Boucher, Jeremie; Mori, Marcelo A; Lee, Kevin Y; Smyth, Graham; Liew, Chong Wee; Macotela, Yazmin; Rourk, Michael; Bluher, Matthias; Russell, Steven J; Kahn, C Ronald

    2012-06-12

    Insulin and insulin-like growth factor 1 (IGF-1) have important roles in adipocyte differentiation, glucose tolerance and insulin sensitivity. Here to assess how these pathways can compensate for each other, we created mice with a double tissue-specific knockout of insulin and IGF-1 receptors to eliminate all insulin/IGF-1 signalling in fat. These FIGIRKO mice had markedly decreased white and brown fat mass and were completely resistant to high fat diet-induced obesity and age- and high fat diet-induced glucose intolerance. Energy expenditure was increased in FIGIRKO mice despite a >85% reduction in brown fat mass. However, FIGIRKO mice were unable to maintain body temperature when placed at 4 °C. Brown fat activity was markedly decreased in FIGIRKO mice but was responsive to β3-receptor stimulation. Thus, insulin/IGF-1 signalling has a crucial role in the control of brown and white fat development, and, when disrupted, leads to defective thermogenesis and a paradoxical increase in basal metabolic rate.

  10. Phenotypic improvement of dystrophic muscles by rAAV/microdystrophin vectors is augmented by Igf1 codelivery.

    PubMed

    Abmayr, Simone; Gregorevic, Paul; Allen, James M; Chamberlain, Jeffrey S

    2005-09-01

    The absence of dystrophin in Duchenne muscular dystrophy (DMD) leads to sarcolemmal instability and enhances the susceptibility of muscle fibers to contraction-induced injury. Various viral vectors have been used to deliver mini- and microdystrophin expression cassettes to muscles of dystrophin-deficient mdx mice, significantly increasing both the morphological and the functional properties of the muscles. However, dystrophin delivery to adult mdx mice has not yielded a complete rescue of the dystrophic phenotype. Here we investigated a novel strategy involving dual gene transfer of recombinant adeno-associated viral vectors expressing either microdystrophin (rAAV-muDys) or a muscle-specific isoform of Igf-1 (rAAV-mIgf-1). Injection of mdx muscles with rAAV-muDys reduced myofiber degeneration and turnover and increased their resistance to mechanical injury, but did not increase muscle mass or force generation. Injection of mdx muscles with rAAV-mIgf-1 led to increased muscle mass, but did not provide protection against mechanical injury or halt myofiber degeneration, leading to loss of the vector over time. In contrast, co-injection of the rAAV-muDys and rAAV-mIgf-1 vectors resulted in increased muscle mass and strength, reduced myofiber degeneration, and increased protection against contraction-induced injury. These results suggest that a dual-gene, combinatorial strategy could enhance the efficacy of gene therapy of DMD.

  11. Craniopharyngioma cell growth is promoted by growth hormone (GH) and is inhibited by tamoxifen: involvement of growth hormone receptor (GHR) and IGF-1 receptor (IGF-1R).

    PubMed

    Li, Qiang; You, Chao; Liu, Liang; Rao, Zhengxi; Sima, Xiutian; Zhou, Liangxue; Xu, Jianguo

    2013-01-01

    Hormone receptors are related to the biological behavior and recurrence of craniopharyngioma (CP). The effect of therapeutic growth hormone (GH) replacement on CP growth remains largely unclear. We intended to study expression patterns of GH-related receptors in CP, and to study the effect of GH and its mediator, insulin-like growth factor-1 (IGF-1), as well as tamoxifen, on primary CP cell cultures. Primary cell cultures were established from fresh tumor specimens. The expression of GH receptor (GHR) and IGF-1 receptor (IGF-1R) in tumor specimens was studied using immunohistochemistry. Cell cultures were treated with various concentrations of recombinant GH, IGF-1 and tamoxifen. Cell growth promotion or inhibition was assayed using the Trypan blue dye exclusion test of cell viability. Expression of GHR, IGF-1R, phosphorylated-Akt and Akt after treatment was studied using Western blot assay. Twenty-nine primary cultures from 36 patients were established. GHR and IGF-1R were expressed in tumor tissue. The promotion of cell growth by GH compared to control was most prominent at 100 ng/mL, while inhibition by tamoxifen was concentration dependent. IGF-1 was more effective in promoting growth in CP cell cultures with high IGF-1R expression, and it increased phosphorylation of Akt protein. Primary cell cultures can be established in more than 80% of fresh CP specimens. GH and its endogenous mediator, IGF-1, promotes CP cell growth in vitro, while tamoxifen inhibits growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Early IGF-1 primes visual cortex maturation and accelerates developmental switch between NKCC1 and KCC2 chloride transporters in enriched animals.

    PubMed

    Baroncelli, Laura; Cenni, Maria Cristina; Melani, Riccardo; Deidda, Gabriele; Landi, Silvia; Narducci, Roberta; Cancedda, Laura; Maffei, Lamberto; Berardi, Nicoletta

    2017-02-01

    Environmental enrichment (EE) has a remarkable impact on brain development. Continuous exposure to EE from birth determines a significant acceleration of visual system maturation both at retinal and cortical levels. A pre-weaning enriched experience is sufficient to trigger the accelerated maturation of the visual system, suggesting that factors affected by EE during the first days of life might prime visual circuits towards a faster development. The search for such factors is crucial not only to gain a better understanding of the molecular hierarchy of brain development but also to identify molecular pathways amenable to be targeted to correct atypical brain developmental trajectories. Here, we showed that IGF-1 levels are increased in the visual cortex of EE rats as early as P6 and this is a crucial event for setting in motion the developmental program induced by EE. Early intracerebroventricular (i.c.v.) infusion of IGF-1 in standard rats was sufficient to mimic the action of EE on visual acuity development, whereas blocking IGF-1 signaling by i.c.v. injections of the IGF-1 receptor antagonist JB1 prevented the deployment of EE effects. Early IGF-1 decreased the ratio between the expression of NKCC1 and KCC2 cation/chloride transporters, and the reversal potential for GABAAR-driven Cl(-) currents (ECl) was shifted toward more negative potentials, indicating that IGF-1 is a crucial factor in accelerating the maturation of GABAergic neurotransmission and promoting the developmental switch of GABA polarity from excitation to inhibition. In addition, early IGF-1 promoted a later occurring increase in its own expression, suggesting a priming effect of early IGF-1 in driving post-weaning cortical maturation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Regulation of pituitary GnRH receptor and gonadotropin subunits by IGF1 and GnRH in prepubertal male coho salmon.

    PubMed

    Luckenbach, J Adam; Dickey, Jon T; Swanson, Penny

    2010-07-01

    Insulin-like growth factor 1 (IGF1) is a key somatotropic hormone that may convey growth status to the reproductive endocrine system. This study examined effects of IGF1 alone or in combination with gonadotropin-releasing hormone (GnRH) on pituitary transcripts for GnRH receptor (GnRHR) variants, follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), and IGF, as well as secretion of FSH in vitro. Three experiments were conducted with dispersed pituitary cells of prepubertal male coho salmon (Oncorhynchus kisutch) to determine the time course of the response to IGF1, IGF1 concentration response, and GnRH concentration response. IGF1 consistently elevated pituitary transcripts for gnrhr1 and the four gonadotropin subunits (fshb, lhb, cga1, and cga2) by day 10 of culture, while suppressing gh and igf2. Short-term treatment with GnRH (24h) induced minor increases in transcripts for fshb, cga1, and cga2, but suppressed lhb and strongly inhibited gnrhr1 expression. IGF1 significantly increased GnRH-stimulated FSH protein release by the pituitary cells, although not as robustly as previously observed in more reproductively advanced salmon. Our results demonstrate that IGF1 increases steady-state mRNA levels of gnrhr1 and four gonadotropin subunits, and may act alone or with GnRH to increase pituitary FSH release in male coho salmon, over 1year before puberty. These findings suggest that IGF1 may prime pituitary gonadotrope cells of prepubertal salmon to respond to GnRH by stimulating synthesis of GnRHR and FSH during puberty onset. (c) 2009 Elsevier Inc. All rights reserved.

  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. 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

  16. 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.

  17. Familial short stature and intrauterine growth retardation associated with a novel mutation in the IGF-I receptor (IGF1R) gene.

    PubMed

    Labarta, José I; Barrio, Eva; Audí, Laura; Fernández-Cancio, Mónica; Andaluz, Pilar; de Arriba, Antonio; Puga, Beatriz; Calvo, María T; Mayayo, Esteban; Carrascosa, Antonio; Ferrández-Longás, Angel

    2013-02-01

    IGF-I is essential for normal human growth and mediates its effects through the IGF1R. IG