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Sample records for igf-i sensitive cell

  1. Phosphatidylinositol 3-Kinase (PI3K) Activity Bound to Insulin-like Growth Factor-I (IGF-I) Receptor, which Is Continuously Sustained by IGF-I Stimulation, Is Required for IGF-I-induced Cell Proliferation*

    Science.gov (United States)

    Fukushima, Toshiaki; Nakamura, Yusaku; Yamanaka, Daisuke; Shibano, Takashi; Chida, Kazuhiro; Minami, Shiro; Asano, Tomoichiro; Hakuno, Fumihiko; Takahashi, Shin-Ichiro

    2012-01-01

    Continuous stimulation of cells with insulin-like growth factors (IGFs) in G1 phase is a well established requirement for IGF-induced cell proliferation; however, the molecular components of this prolonged signaling pathway that is essential for cell cycle progression from G1 to S phase are unclear. IGF-I activates IGF-I receptor (IGF-IR) tyrosine kinase, followed by phosphorylation of substrates such as insulin receptor substrates (IRS) leading to binding of signaling molecules containing SH2 domains, including phosphatidylinositol 3-kinase (PI3K) to IRS and activation of the downstream signaling pathways. In this study, we found prolonged (>9 h) association of PI3K with IGF-IR induced by IGF-I stimulation. PI3K activity was present in this complex in thyrocytes and fibroblasts, although tyrosine phosphorylation of IRS was not yet evident after 9 h of IGF-I stimulation. IGF-I withdrawal in mid-G1 phase impaired the association of PI3K with IGF-IR and suppressed DNA synthesis the same as when PI3K inhibitor was added. Furthermore, we demonstrated that Tyr1316-X-X-Met of IGF-IR functioned as a PI3K binding sequence when this tyrosine is phosphorylated. We then analyzed IGF signaling and proliferation of IGF-IR−/− fibroblasts expressing exogenous mutant IGF-IR in which Tyr1316 was substituted with Phe (Y1316F). In these cells, IGF-I stimulation induced tyrosine phosphorylation of IGF-IR and IRS-1/2, but mutated IGF-IR failed to bind PI3K and to induce maximal phosphorylation of GSK3β and cell proliferation in response to IGF-I. Based on these results, we concluded that PI3K activity bound to IGF-IR, which is continuously sustained by IGF-I stimulation, is required for IGF-I-induced cell proliferation. PMID:22767591

  2. The Insulin-like Growth Factor (IGF)-I E-Peptides Modulate Cell Entry of the Mature IGF-I Protein

    OpenAIRE

    Pfeffer, Lindsay A.; Brisson, Becky K.; Lei, Hanqin; Barton, Elisabeth R.

    2009-01-01

    Insulin-like growth factor (IGF)-I is a critical protein for cell development and growth. Alternative splicing of the igf1 gene gives rise to multiple isoforms. In rodents, proIGF-IA and proIGF-IB have different carboxy-terminal extensions called the E-peptides (EA and EB) and upon further posttranslational processing, produce the identical mature IGF-I protein. Rodent EB has been reported to have mitogenic and motogenic effects independent of IGF-I. However, effects of EA or EB on mature IGF...

  3. Igf-I regulates pheochromocytoma cell proliferation and survival in vitro and in vivo.

    Science.gov (United States)

    Fernández, María Celia; Venara, Marcela; Nowicki, Susana; Chemes, Héctor E; Barontini, Marta; Pennisi, Patricia A

    2012-08-01

    IGFs are involved in malignant transformation and growth of several tissues, including the adrenal medulla. The present study was designed to evaluate the impact of IGF-I on pheochromocytoma development. We used a murine pheochromocytoma (MPC) cell line (MPC4/30) and an animal model with a reduction of 75% in circulating IGF-I levels [liver-IGF-I-deficient (LID) mice] to perform studies in vitro and in vivo. We found that, in culture, IGF-I stimulation increases proliferation, migration, and anchorage-independent growth, whereas it inhibits apoptosis of MPC cells. When injected to control and to LID mice, MPC cells grow and form tumors with features of pheochromocytoma. Six weeks after cell inoculation, all control mice developed sc tumors. In contrast, in 73% of LID mice, tumor development was delayed to 7-12 wk, and the remaining 27% did not develop tumors up to 12 wk after inoculation. LID mice harboring MPC cells and treated with recombinant human IGF-I (LID+) developed tumors as controls. Tumors developed in control, LID, and LID+ mice had similar histology and were similarly positive for IGF-I receptor expression. The apoptotic index was higher in tumors from LID mice compared with those from control mice, whereas vascular density was decreased. In summary, our work demonstrates that IGF-I has a critical role in maintaining tumor phenotype and survival of already transformed pheochromocytoma cells and is required for the initial establishment of these tumors, providing encouragement to carry on research studies to address the IGF-I/IGF-I receptor system as a target of therapeutic strategies for pheochromocytoma treatment in the future.

  4. IGF-I Stimulates Cooperative Interaction between the IGF-I Receptor and CSK Homologous Kinase that Regulates SHPS-1 Phosphorylation in Vascular Smooth Muscle Cells

    Science.gov (United States)

    Radhakrishnan, Yashwanth; Shen, Xinchun; Maile, Laura A.; Xi, Gang

    2011-01-01

    IGF-I plays an important role in smooth muscle cell proliferation and migration. In vascular smooth muscle cells cultured in 25 mm glucose, IGF-I stimulated a significant increase in Src homology 2 domain containing protein tyrosine phosphatase substrate-1 (SHPS-1) phosphorylation compared with 5 mm glucose and this increase was required for smooth muscle cell proliferation. A proteome-wide screen revealed that carboxyl-terminal SRC kinase homologous kinase (CTK) bound directly to phosphotyrosines in the SHPS-1 cytoplasmic domain. Because the kinase(s) that phosphorylates these tyrosines in response to IGF-I is unknown, we determined the roles of IGF-I receptor (IGF-IR) and CTK in mediating SHPS-1 phosphorylation. After IGF-I stimulation, CTK was recruited to IGF-IR and subsequently to phospho-SHPS-1. Expression of an IGF-IR mutant that eliminated CTK binding reduced CTK transfer to SHPS-1, SHPS-1 phosphorylation, and cell proliferation. IGF-IR phosphorylated SHPS-1, which provided a binding site for CTK. CTK recruitment to SHPS-1 resulted in a further enhancement of SHPS-1 phosphorylation. CTK knockdown also impaired IGF-I-stimulated SHPS-1 phosphorylation and downstream signaling. Analysis of specific tyrosines showed that mutation of tyrosines 428/452 in SHPS-1 to phenylalanine reduced SHPS-1 phosphorylation but allowed CTK binding. In contrast, the mutation of tyrosines 469/495 inhibited IGF-IR-mediated the phosphorylation of SHPS-1 and CTK binding, suggesting that IGF-IR phosphorylated Y469/495, allowing CTK binding, and that CTK subsequently phosphorylated Y428/452. Based on the above findings, we conclude that after IGF-I stimulation, CTK is recruited to IGF-IR and its recruitment facilitates CTK's subsequent association with phospho-SHPS-1. This results in the enhanced CTK transfer to SHPS-1, and the two kinases then fully phosphorylate SHPS-1, which is necessary for IGF-I stimulated cellular proliferation. PMID:21799000

  5. Conditionally immortalized human pancreatic stellate cell lines demonstrate enhanced proliferation and migration in response to IGF-I

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl, Ann H., E-mail: ann.rosendahl@med.lu.se [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden); Lund University and Skåne University Hospital, Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund (Sweden); Gundewar, Chinmay; Said Hilmersson, Katarzyna [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden); Ni, Lan; Saleem, Moin A. [University of Bristol, School of Clinical Sciences, Children' s Renal Unit and Academic Renal Unit, Bristol (United Kingdom); Andersson, Roland [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden)

    2015-01-15

    Pancreatic stellate cells (PSCs) play a key role in the dense desmoplastic stroma associated with pancreatic ductal adenocarcinoma. Studies on human PSCs have been minimal due to difficulty in maintaining primary PSC in culture. We have generated the first conditionally immortalized human non-tumor (NPSC) and tumor-derived (TPSC) pancreatic stellate cells via transformation with the temperature-sensitive SV40 large T antigen and human telomerase (hTERT). These cells proliferate at 33°C. After transfer to 37°C, the SV40LT is switched off and the cells regain their primary PSC phenotype and growth characteristics. NPSC contained cytoplasmic vitamin A-storing lipid droplets, while both NPSC and TPSC expressed the characteristic markers αSMA, vimentin, desmin and GFAP. Proteome array analysis revealed that of the 55 evaluated proteins, 27 (49%) were upregulated ≥3-fold in TPSC compared to NPSC, including uPA, pentraxin-3, endoglin and endothelin-1. Two insulin-like growth factor binding proteins (IGFBPs) were inversely expressed. Although discordant IGFBP-2 and IGFBP-3 levels, IGF-I was found to stimulate proliferation of both NPSC and TPSC. Both basal and IGF-I stimulated motility was significantly enhanced in TPSC compared to NPSC. In conclusion, these cells provide a unique resource that will facilitate further study of the active stroma compartment associated with pancreatic cancer. - Highlights: • Generation of human conditionally immortalized human pancreatic stellate cell lines. • Temperature-sensitive SV40LT allows switch to primary PSC phenotype characteristics. • Proteome profiling revealed distinct expression patterns between TPSC and NPSC. • Enhanced IGF-I-stimulated proliferation and motility by TPSC compared to NPSC.

  6. Lycopene inhibits IGF-I signal transduction and growth in normal prostate epithelial cells by decreasing DHT-modulated IGF-I production in co-cultured reactive stromal cells.

    Science.gov (United States)

    Liu, Xunxian; Allen, Jeffrey D; Arnold, Julia T; Blackman, Marc R

    2008-04-01

    Prostate stromal and epithelial cell communication is important in prostate functioning and cancer development. Primary human stromal cells from normal prostate stromal cells (PRSC) maintain a smooth muscle phenotype, whereas those from prostate cancer (6S) display reactive and fibroblastic characteristics. Dihydrotestosterone (DHT) stimulates insulin-like growth factor-I (IGF-I) production by 6S but not PSRC cells. Effects of reactive versus normal stroma on normal human prostate epithelial (NPE or PREC) cells are poorly understood. We co-cultured NPE plus 6S or PRSC cells to compare influences of different stromal cells on normal epithelium. Because NPE and PREC cells lose androgen receptor (AR) expression in culture, DHT effects must be modulated by associated stromal cells. When treated with camptothecin (CM), NPE cells, alone and in stromal co-cultures, displayed a dose-dependent increase in DNA fragmentation. NPE/6S co-cultures exhibited reduced CM-induced cell death with exposure to DHT, whereas NPE/PRSC co-cultures exhibited CM-induced cell death regardless of DHT treatment. DHT blocked CM-induced, IGF-I-mediated, NPE death in co-cultured NPE/6S cells without, but not with, added anti-IGF-I and anti-IGF-R antibodies. Lycopene consumption is inversely related to human prostate cancer risk and inhibits IGF-I and androgen signaling in rat prostate cancer. In this study, lycopene, in dietary concentrations, reversed DHT effects of 6S cells on NPE cell death, decreased 6S cell IGF-I production by reducing AR and beta-catenin nuclear localization and inhibited IGF-I-stimulated NPE and PREC growth, perhaps by attenuating IGF-I's effects on serine phosphorylation of Akt and GSK3beta and tyrosine phosphorylation of GSK3. This study expands the understanding of the preventive mechanisms of lycopene in prostate cancer.

  7. Stimulation of proteoglycans by IGF I and II in microvessel and large vessel endothelial cells

    International Nuclear Information System (INIS)

    Bar, R.S.; Dake, B.L.; Stueck, S.

    1987-01-01

    Endothelial cells were cultured from bovine capillaries and pulmonary arteries, and the effect of insulinlike growth factor (IGF) I and II (multiplication-stimulating activity) and insulin on the synthesis of proteoglycans was determined. IGF I and II stimulated 35 SO 4 incorporation into proteoglycans in a dose-dependent manner in both microvessel and pulmonary artery endothelial cells with maximum threefold increases. In pulmonary artery cells, the IGFs caused a general stimulation of all classes of glycosaminoglycan-containing proteoglycans. In microvessel endothelial cells, the IGFs appeared to preferentially increase heparan sulfate-containing proteoglycans. Insulin, at concentrations up to 10 -6 M, had no effect on the synthesis of proteoglycans in either microvessel or pulmonary arterial endothelial cells. Thus, the IGFs stimulate the synthesis of proteoglycans in both microvessel and large vessel endothelial cells, a property that is not mimicked by insulin. Because vascular endothelial cells are bathed by IGFs in vivo, such IGF-mediated functions are likely to be significant in both the normal physiology of vascular endothelium and in disease states such as diabetes mellitus

  8. Enhanced contractile force generation by artificial skeletal muscle tissues using IGF-I gene-engineered myoblast cells.

    Science.gov (United States)

    Sato, Masanori; Ito, Akira; Kawabe, Yoshinori; Nagamori, Eiji; Kamihira, Masamichi

    2011-09-01

    The aim of this study was to investigate whether insulin-like growth factor (IGF)-I gene delivery to myoblast cells promotes the contractile force generated by hydrogel-based tissue-engineered skeletal muscles in vitro. Two retroviral vectors allowing doxycycline (Dox)-inducible expression of the IGF-I gene were transduced into mouse myoblast C2C12 cells to evaluate the effects of IGF-I gene expression on these cells. IGF-I gene expression stimulated the proliferation of C2C12 cells, and a significant increase in the growth rate was observed for IGF-I-transduced C2C12 cells with Dox addition, designated C2C12/IGF (Dox+) cells. Quantitative morphometric analyses showed that the myotubes induced from C2C12/IGF (Dox+) cells had a larger area and a greater width than control myotubes induced from normal C2C12 cells. Artificial skeletal muscle tissues were prepared from the respective cells using hydrogels composed of type I collagen and Matrigel. Western blot analyses revealed that the C2C12/IGF (Dox+) tissue constructs showed activation of a skeletal muscle hypertrophy marker (Akt) and enhanced expression of muscle-specific markers (myogenin, myosin heavy chain and tropomyosin). Moreover, the creatine kinase activity was increased in the C2C12/IGF (Dox+) tissue constructs. The C2C12/IGF (Dox+) tissue constructs contracted in response to electrical pulses, and generated a significantly higher physical force than the control C2C12 tissue constructs. These findings indicate that IGF-I gene transfer has the potential to yield functional skeletal muscle substitutes that are capable of in vivo restoration of the load-bearing function of injured muscle or acting as in vitro electrically-controlled bio-actuators. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Comparison of Efficacy of Endogenous and Exogenous IGF-I in Stimulating Matrix Production in Neonatal and Mature Chondrocytes.

    Science.gov (United States)

    Aguilar, Izath N; Trippel, Stephen B; Shi, Shuiliang; Bonassar, Lawrence J

    2015-10-01

    The goal of this study was to compare the efficacy of endogenous upregulation of IGF-I by gene therapy and exogenous addition of insulin-like growth factor I (IGF-I) in enhancing proteoglycan synthesis by skeletally mature and neonatal chondrocytes. Chondrocyte transplantation therapy is a common treatment for focal cartilage lesions, with both mature and neonatal chondrocytes used as a cell source. Additionally, gene therapy strategies to upregulate growth factors such as IGF-I have been proposed to augment chondrocyte transplantation therapies. Both skeletally mature and neonatal chondrocytes were exposed to either an adeno-associated virus-based plasmid containing the IGF-I gene or exogenous IGF-I. Analysis of IGF-I and glycosaminoglycan production using a 4-parameter dose-response model established a clear connection between the amount of IGF-I produced by cells and their biosynthetic response. Both neonatal and mature chondrocytes showed this relationship, but the sensitivities were quite different, with EC50 of 0.57 ng/mL for neonatal chondrocytes and EC50 of 8.70 ng/mL IGF-I for skeletally mature chondrocytes. These data suggest that IGF-I gene therapy may be more effective with younger cell sources. Both cell types were less sensitive to exogenous IGF-I than endogenous IGF-I.

  10. The IGF-I/JAK2-STAT3/miR-21 signaling pathway may be associated with human renal cell carcinoma cell growth.

    Science.gov (United States)

    Su, Ying; Zhao, An; Cheng, Guoping; Xu, Jingjing; Ji, Enming; Sun, Wenyong

    2017-07-04

    Renal cell carcinoma (RCC) is the highest mortality rate of the genitourinary cancers, and the treatment options are very limited. Thus, identification of molecular mechanisms underlying RCC tumorigenesis, is critical for identifying biomarkers for RCC diagnosis and prognosis. To validate whether the IGF-I/JAK2-STAT3/miR-21 signaling pathway is associated with human RCC cell growth. qRT-PCR and Western blotting were used to detect the mRNA and protein expression levels, respectively. The MTT assay was performed to determine cell survival rate. The Annexin V-FITC/PI apoptosis detection kit was used to detect cell apoptosis. We employed RCC tissues and cell lines (A498; ACHN; Caki-1; Caki-2 and 786-O) in the study. IGF-I, and its inhibitor (NT-157) were administrated to detect the effects of IGF-I on the expression of miR-21 and p-JAK2. JAK2 inhibitor (AG490), and si-STAT3 were used to detect the effects of JAK2/STAT3 signaling pathway on the expression of miR-21. In our study, we firstly showed that the expression levels of IGF-I and miR-21 were up-regulated in RCC tissues and cell lines. After exogenous IGF-I treatment, the expression levels of miR-21, p-IGF-IR and p-JAK2 were significantly increased, whereas NT-157 treatment showed the reversed results. Further study indicated that JAK2 inhibitor or si-STAT3 significantly reversed the IGF-I-induced miR-21 expression level. Finally, we found that IGF-I treatment significantly prompted human RCC cell survival and inhibited cell apoptosis, and NT-157 treatment showed the reversed results. The IGF-I/JAK2-STAT3/miR-21 signaling pathway may be associated with human RCC cell growth.

  11. Differential roles of MAPK-Erk1/2 and MAPK-p38 in insulin or insulin-like growth factor-I (IGF-I) signaling pathways for progesterone production in human ovarian cells.

    Science.gov (United States)

    Seto-Young, D; Avtanski, D; Varadinova, M; Park, A; Suwandhi, P; Leiser, A; Parikh, G; Poretsky, L

    2011-06-01

    Insulin and insulin like-growth factor-I (IGF-I) participate in the regulation of ovarian steroidogenesis. In insulin resistant states ovaries remain sensitive to insulin because insulin can activate alternative signaling pathways, such as phosphatidylinositol-3-kinase (PI-3 kinase) and mitogen-activated protein-kinase (MAPK) pathways, as well as insulin receptors and type 1 IGF receptors. We investigated the roles of MAPK-Erk1/2 and MAPK-p38 in insulin and IGF-I signaling pathways for progesterone production in human ovarian cells. Human ovarian cells were cultured in tissue culture medium in the presence of varying concentrations of insulin or IGF-I, with or without PD98059, a specific MAPK-Erk1/2 inhibitor, with or without SB203580, a specific MAPK-p38 inhibitor or with or without a specific PI-3-kinase inhibitor LY294002. Progesterone concentrations were measured using radioimmunoassay. PD98059 alone stimulated progesterone production in a dose-dependent manner by up to 65% (pprogesterone production by 13-18% (pprogesterone production by 17-20% (pprogesterone production by 20-30% (pprogesterone production by 40-60% (pprogesterone synthesis while SB203580 abolished insulin-induced progesterone production. Either PD98059 or SB203580 abolished IGF-I-induced progesterone production. Both MAPK-Erk1/2 and MAPK-p38 participate in IGF-I-induced signaling pathways for progesterone production, while insulin-induced progesterone production requires MAPK-p38, but not MAPK-Erk1/2. These studies provide further evidence for divergence of insulin and IGF-I signaling pathways for human ovarian cell steroidogenesis. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Binding of IGF I and IGF I-stimulated phosphorylation in canine renal basolateral membranes

    International Nuclear Information System (INIS)

    Hammerman, M.R.; Gavin, J.R. III.

    1986-01-01

    To characterize the interaction of the renal proximal tubular cell with insulin like growth factor I (IGF I), we measured binding of 125 I-IGF I to proximal tubular basolateral membranes from dog kidney and induced IGF I-stimulated phosphorylation of basolateral membranes. Specific binding of 125 I-IGF I to basolateral membranes was observed that was half-maximal at between 10(-9) and 10(-8) M IGF I. 125 I-IGF I was affinity cross-linked to a 135,000 Mr protein in basolateral membranes that was distinct from the alpha-subunit of the insulin receptor and from the IGF II receptor. IGF I-stimulated phosphorylation of a 92,000 Mr protein was effected in detergent-solubilized membranes incubated with 100 microM [gamma- 32 P]ATP. The 32 P-labeled protein was distinct from the beta-subunit of the insulin receptor, the 32 P phosphorylation of which was stimulated by insulin. We conclude that specific receptors for IGF I are present in the basolateral membrane of the renal proximal tubular cell. Physiological actions of IGF I at this nephron site may occur through the binding of this peptide circulating in plasma, to specific basolateral membrane receptors, followed by IGF I stimulated phosphorylation

  13. DHT and testosterone, but not DHEA or E2, differentially modulate IGF-I, IGFBP-2, and IGFBP-3 in human prostatic stromal cells.

    Science.gov (United States)

    Le, Hanh; Arnold, Julia T; McFann, Kimberly K; Blackman, Marc R

    2006-05-01

    Prostate cancer is one of the four most common cancers in the United States, affecting one of six men. Increased serum levels of androgens and IGF-I are associated with an augmented risk of prostate cancer. Dihydrotestosterone (DHT) and testosterone (T) stimulate prostate cancer cell growth, development, and function, whereas the effects of DHT and T in prostate stromal cells, and of dehydroepiandrosterone (DHEA) in prostate cancer or stromal cells, are uncertain. We investigated the actions of DHT, T, DHEA, and estradiol (E2) on insulin-like growth factor (IGF)-I, IGF-II, IGF-I receptor (R), IGF-binding protein (IGFBP)-2, IGFBP-3, and IGFBP-5 in primary cultures of human prostatic stromal cells by assessing cell proliferation, mRNA expression, and protein secretion by MTT growth assay, quantitative real-time PCR, and ELISA, respectively. DHT and T each increased IGF-I (7-fold) and decreased IGFBP-3 (2-fold) mRNA expression and protein secretion in a dose- and time-dependent manner and increased IGFBP-2 (2-fold) mRNA in a dose- and time-dependent manner. DHEA and E2 did not significantly alter these measures. Flutamide abolished the DHT-modulated increases in IGF-I and IGFBP-2, suggesting that the influences of DHT and T on these measures were androgen receptor mediated. None of the four steroids significantly affected IGF-IR, IGF-II, or IGFBP-5 mRNA levels or stromal cell proliferation. The effects of DHT on IGF-I, IGFBP-2, and IGFBP-3 were more pronounced in stromal cultures that did not express desmin. These data suggest that DHT and T promote prostate growth partly via modulation of the stromal cell IGF axis, with potential paracrine effects on prostate epithelial cells.

  14. Metformin-mediated growth inhibition involves suppression of the IGF-I receptor signalling pathway in human pancreatic cancer cells

    International Nuclear Information System (INIS)

    Karnevi, Emelie; Said, Katarzyna; Andersson, Roland; Rosendahl, Ann H

    2013-01-01

    Epidemiological studies have shown direct associations between type 2 diabetes and obesity, both conditions associated with hyperglycaemia and hyperinsulinemia, and the risk of pancreatic cancer. Up to 80% of pancreatic cancer patients present with either new-onset type 2 diabetes or impaired glucose tolerance at the time of diagnosis. Recent population studies indicate that the incidence of pancreatic cancer is reduced among diabetics taking metformin. In this study, the effects of exposure of pancreatic cancer cells to high glucose levels on their growth and response to metformin were investigated. The human pancreatic cancer cell lines AsPC-1, BxPC-3, PANC-1 and MIAPaCa-2 were grown in normal (5 mM) or high (25 mM) glucose conditions, with or without metformin. The influence by metformin on proliferation, apoptosis and the AMPK and IGF-IR signalling pathways were evaluated in vitro. Metformin significantly reduced the proliferation of pancreatic cancer cells under normal glucose conditions. Hyperglycaemia however, protected against the metformin-induced growth inhibition. The anti-proliferative actions of metformin were associated with an activation of AMP-activated protein kinase AMPK Thr172 together with an inhibition of the insulin/insulin-like growth factor-I (IGF-I) receptor activation and downstream signalling mediators IRS-1 and phosphorylated Akt. Furthermore, exposure to metformin during normal glucose conditions led to increased apoptosis as measured by poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, exposure to high glucose levels promoted a more robust IGF-I response and Akt activation which correlated to stimulated AMPK Ser485 phosphorylation and impaired AMPK Thr172 phosphorylation, resulting in reduced anti-proliferative and apoptotic effects by metformin. Our results indicate that metformin has direct anti-tumour activities in pancreatic cancer cells involving AMPK Thr172 activation and suppression of the insulin/IGF signalling pathways

  15. Insulin-like growth factor (IGF) binding protein from human decidua inhibits the binding and biological action of IGF-I in cultured choriocarcinoma cells

    International Nuclear Information System (INIS)

    Ritvos, O.; Ranta, T.; Jalkanen, J.; Suikkari, A.M.; Voutilainen, R.; Bohn, H.; Rutanen, E.M.

    1988-01-01

    The placenta expresses genes for insulin-like growth factors (IGFs) and possesses IGF-receptors, suggesting that placental growth is regulated by IGFs in an autocrine manner. We have previously shown that human decidua, but not placenta, synthesizes and secretes a 34 K IGF-binding protein (34 K IGF-BP) called placental protein 12. We now used human choriocarcinoma JEG-3 cell monolayer cultures and recombinant (Thr59)IGF-I as a model to study whether the decidual 34 K IGF-BP is able to modulate the receptor binding and biological activity of IGFs in trophoblasts. JEG-3 cells, which possess type I IGF receptors, were unable to produce IGF-BPs. Purified 34 K IGF-BP specifically bound [125I]iodo-(Thr59)IGF-I. Multiplication-stimulating activity had 2.5% the potency of (Thr59)IGF-I, and insulin had no effect on the binding of [125I] iodo-(Thr59)IGF-I. 34 K IGF-BP inhibited the binding of [125I] iodo-(Thr59)IGF-I to JEG-3 monolayers in a concentration-dependent manner by forming with the tracer a soluble complex that could not bind to the cell surface as demonstrated by competitive binding and cross-linking experiments. After incubating the cell monolayers with [125I]iodo-(Thr59)IGF-I in the presence of purified binding protein, followed by cross-linking, no affinity labeled bands were seen on autoradiography. In contrast, an intensely labeled band at 40 K was detected when the incubation medium was analyzed, suggesting that (Thr59)IGF-I and 34 K IGF-BP formed a complex in a 1:1 molar ratio. Also, 34 K IGF-BP inhibited both basal and IGF-I-stimulated uptake of alpha-[3H]aminoisobutyric acid in JEG-3 cells. RNA analysis revealed that IGF-II is expressed in JEG-3 cells

  16. Insulin-like growth factor (IGF)-I binding to a cell membrane associated IGF binding protein-3 acid-labile subunit complex in human anterior pituitary gland

    NARCIS (Netherlands)

    Wilczak, N; Kuhl, N; Chesik, D; Geerts, A; Luiten, P; De Keyser, J

    The binding characteristics of [(125) I]insulin-like growth factor (IGF)-I were studied in human brain and pituitary gland. Competition binding studies with DES(1-3)IGF-I and R-3 -IGF-I, which display high affinity for the IGF-I receptor and low affinity for IGF binding proteins (IGFBPs), were

  17. Overexpression of IGF-I receptor in HeLa cells enhances in vivo radioresponse

    International Nuclear Information System (INIS)

    Kaneko, Haruna; Yu, Dong; Miura, Masahiko

    2007-01-01

    Insulin-like growth factor I receptor (IGF-IR) is a transmembrane receptor tyrosine kinase whose activation strongly promotes cell growth and survival. We previously reported that IGF-IR activity confers intrinsic radioresistance in mouse embryo fibroblasts in vitro. However, it is still unclear whether tumor cells overexpressing IGF-IR exhibit radioresistance in vivo. For this purpose, we established HeLa cells that overexpress IGF-IR (HeLa-R), subcutaneously transplanted these cells into nude mice, and examined radioresponse in the resulting solid tumors. HeLa-R cells exhibited typical in vitro phenotypes generally observed in IGF-IR-overexpressing cells, as well as significant intrinsic radioresistance in vitro compared with parent cells. As expected, the transplanted HeLa-R tumors grew at a remarkably higher rate than parent tumors. Histological analysis revealed that HeLa-R tumors expressed more VEGF and had a higher density of tumor vessels. Unexpectedly, a marked growth delay was observed in HeLa-R tumors following 10 Gy of X-irradiation. Immunostaining of HeLa-R tumors for the hypoxia marker pimonidazole revealed a significantly lower level of hypoxic cells. Moreover, clamp hypoxia significantly increased radioresistance in HeLa-R tumors. Tumor microenvironments in vivo generated by the IGF-IR expression thus could be a major factor in determining the tumor radioresponse in vivo

  18. Proline-rich tyrosine kinase 2 (Pyk2 regulates IGF-I-induced cell motility and invasion of urothelial carcinoma cells.

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    Marco Genua

    Full Text Available The insulin-like growth factor receptor I (IGF-IR plays an essential role in transformation by promoting cell growth and protecting cancer cells from apoptosis. We have recently demonstrated that the IGF-IR is overexpressed in invasive bladder cancer tissues and promotes motility and invasion of urothelial carcinoma cells. These effects require IGF-I-induced Akt- and MAPK-dependent activation of paxillin. The latter co-localizes with focal adhesion kinases (FAK at dynamic focal adhesions and is critical for promoting motility of urothelial cancer cells. FAK and its homolog Proline-rich tyrosine kinase 2 (Pyk2 modulate paxillin activation; however, their role in regulating IGF-IR-dependent signaling and motility in bladder cancer has not been established. In this study we demonstrate that FAK was not required for IGF-IR-dependent signaling and motility of invasive urothelial carcinoma cells. On the contrary, Pyk2, which was strongly activated by IGF-I, was critical for IGF-IR-dependent motility and invasion and regulated IGF-I-dependent activation of the Akt and MAPK pathways. Using immunofluorescence and AQUA analysis we further discovered that Pyk2 was overexpressed in bladder cancer tissues as compared to normal tissue controls. Significantly, in urothelial carcinoma tissues there was increased Pyk2 localization in the nuclei as compared to normal tissue controls. These results provide the first evidence of a specific Pyk2 activity in regulating IGF-IR-dependent motility and invasion of bladder cancer cells suggesting that Pyk2 and the IGF-IR may play a critical role in the invasive phenotype in urothelial neoplasia. In addition, Pyk2 and the IGF-IR may serve as novel biomarkers with diagnostic and prognostic significance in bladder cancer.

  19. Postnatal Changes in Testicular Position are Associated with IGF-I and Function of Sertoli and Leydig Cells

    DEFF Research Database (Denmark)

    Koskenniemi, Jaakko J; Virtanen, Helena E; Wohlfahrt-Veje, Christine

    2018-01-01

    position during childhood. Design: Testicular position (the distance from the pubic bone to the upper pole of the testes) at birth, 3 months, 18 months, 36 months, 7 years and reproductive hormones at three months were measured. Setting: Prenatally recruited, prospective longitudinal birth cohort....... Participants: In total 2545 boys were recruited prenatally in a Danish-Finnish birth cohort and had testicular position examination available. A subset of 680 Danish and 362 Finnish boys had serum reproductive hormone concentrations and insulin-like growth factor I (IGF-I) determined at three months. Main...

  20. The pro-Forms of Insulin-Like Growth Factor I (IGF-I) Are Predominant in Skeletal Muscle and Alter IGF-I Receptor Activation

    Science.gov (United States)

    Durzyńska, Julia; Philippou, Anastassios; Brisson, Becky K.; Nguyen-McCarty, Michelle

    2013-01-01

    IGF-I is a key regulator of muscle development and growth. The pre-pro-peptide produced by the Igf1gene undergoes several posttranslational processing steps to result in a secreted mature protein, which is thought to be the obligate ligand for the IGF-I receptor (IGF-IR). The goals of this study were to determine what forms of IGF-I exist in skeletal muscle, and whether the mature IGF-I protein was the only form able to activate the IGF-IR. We measured the proportion of IGF-I species in murine skeletal muscle and found that the predominant forms were nonglycosylated pro-IGF-I and glycosylated pro-IGF-I, which retained the C-terminal E peptide extension, instead of mature IGF-I. These forms were validated using samples subjected to viral expression of IGF-I combined with furin and glycosidase digestion. To determine whether the larger molecular weight IGF-I forms were also ligands for the IGF-IR, we generated each specific form through transient transfection of 3T3 cells and used the enriched media to perform kinase receptor activation assays. Compared with mature IGF-I, nonglycosylated pro-IGF-I had similar ability to activate the IGF-IR, whereas glycosylation of pro-IGF-I significantly reduced receptor activation. Thus, it is important to understand not only the quantity, but also the proportion of IGF-I forms produced, to evaluate the true biological activity of this growth factor. PMID:23407451

  1. PKC{eta} is a negative regulator of AKT inhibiting the IGF-I induced proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shahaf, Galit; Rotem-Dai, Noa; Koifman, Gabriela; Raveh-Amit, Hadas; Frost, Sigal A.; Livneh, Etta, E-mail: etta@bgu.ac.il

    2012-04-15

    The PI3K-AKT pathway is frequently activated in human cancers, including breast cancer, and its activation appears to be critical for tumor maintenance. Some malignant cells are dependent on activated AKT for their survival; tumors exhibiting elevated AKT activity show sensitivity to its inhibition, providing an Achilles heel for their treatment. Here we show that the PKC{eta} isoform is a negative regulator of the AKT signaling pathway. The IGF-I induced phosphorylation on Ser473 of AKT was inhibited by the PKC{eta}-induced expression in MCF-7 breast adenocarcinoma cancer cells. This was further confirmed in shRNA PKC{eta}-knocked-down MCF-7 cells, demonstrating elevated phosphorylation on AKT Ser473. While PKC{eta} exhibited negative regulation on AKT phosphorylation it did not alter the IGF-I induced ERK phosphorylation. However, it enhanced ERK phosphorylation when stimulated by PDGF. Moreover, its effects on IGF-I/AKT and PDGF/ERK pathways were in correlation with cell proliferation. We further show that both PKC{eta} and IGF-I confer protection against UV-induced apoptosis and cell death having additive effects. Although the protective effect of IGF-I involved activation of AKT, it was not affected by PKC{eta} expression, suggesting that PKC{eta} acts through a different route to increase cell survival. Hence, our studies show that PKC{eta} provides negative control on AKT pathway leading to reduced cell proliferation, and further suggest that its presence/absence in breast cancer cells will affect cell death, which could be of therapeutic value.

  2. Expression of IGF-I, IGF-I receptor and IGF binding proteins-1, -2, -3, -4 and -5 in human atherectomy specimens.

    Science.gov (United States)

    Grant, M B; Wargovich, T J; Ellis, E A; Tarnuzzer, R; Caballero, S; Estes, K; Rossing, M; Spoerri, P E; Pepine, C

    1996-12-17

    The molecular and cellular processes that induce rapid atherosclerotic plaque progression in patients with unstable angina and initiate restenosis following coronary interventional procedures are uncertain. We examined primary (de novo) and restenotic lesions retrieved at the time of directional coronary atherectomy for expression of insulin-like-growth factor-I (IGF-I). IGF-I receptor, and five IGF binding proteins (IGFBPs), IGFBP-1, IGFBP-2, IGFBP-3, IGFBP-4, and IGFBP-5 in smooth muscle cells (SMCs) using colloidal gold immunocytochemistry. IGF-1, its receptor and binding proteins were not detected in SMCs of normal coronary arteries. IGF-I localized primarily in synthetic smooth muscle cells (sSMCs) in both de novo and restenotic plaques. IGF-I receptor localized on sSMCs and their processes and colocalized with IGF-I. Although morphometric analysis of IGF-I and IGF-I receptor immunoreactivity in sSMCs of de novo and restenotic lesions showed comparable levels of IGF-I (3.2 +/- 1.0 and 2.9 +/- 0.9, respectively). IGF-I receptor was significantly higher in de novo lesions as compared to restenotic lesions (10.7 +/- 2.5 and 4.2 +/- 1.3, P system.

  3. Metformin downregulates the insulin/IGF-I signaling pathway and inhibits different uterine serous carcinoma (USC) cells proliferation and migration in p53-dependent or -independent manners.

    Science.gov (United States)

    Sarfstein, Rive; Friedman, Yael; Attias-Geva, Zohar; Fishman, Ami; Bruchim, Ilan; Werner, Haim

    2013-01-01

    Accumulating epidemiological evidence shows that obesity is associated with an increased risk of several types of adult cancers, including endometrial cancer. Chronic hyperinsulinemia, a typical hallmark of diabetes, is one of the leading factors responsible for the obesity-cancer connection. Numerous cellular and circulating factors are involved in the biochemical chain of events leading from hyperinsulinemia and insulin resistance to increased cancer risk and, eventually, tumor development. Metformin is an oral anti-diabetic drug of the biguanide family used for treatment of type 2 diabetes. Recently, metformin was shown to exhibit anti-proliferative effects in ovarian and Type I endometrial cancer, although the mechanisms responsible for this non-classical metformin action remain unclear. The insulin-like growth factors (IGFs) play a prominent role in cancer biology and their mechanisms of action are tightly interconnected with the insulin signaling pathways. Given the cross-talk between the insulin and IGF signaling pathways, the aim of this study was to examine the hypothesis that the anti-proliferative actions of metformin in uterine serous carcinoma (USC) are potentially mediated via suppression of the IGF-I receptor (IGF-IR) pathway. Our results show that metformin interacts with the IGF pathway, and induces apoptosis and inhibition of proliferation and migration of USC cell lines with both wild type and mutant p53. Taken together, our results suggest that metformin therapy could be a novel and attractive therapeutic approach for human USC, a highly aggressive variant of endometrial cancer.

  4. IGF-I abuse in sport.

    Science.gov (United States)

    Guha, Nishan; Dashwood, Alexander; Thomas, Nicholas J; Skingle, Alexander J; Sönksen, Peter H; Holt, Richard I G

    2009-09-01

    It is widely believed that growth hormone (GH) is abused by athletes for its anabolic and lipolytic effects. Many of the physiological effects of GH are mediated by the production of insulin-like growth factor-I (IGF-I). Both GH and IGF-I appear on the World Anti-Doping Agency list of prohibited substances. Little is known, however, about the prevalence of abuse with exogenous IGF-I. IGF-I has effects on carbohydrate, lipid and protein metabolism and some of these actions could prove beneficial to competitive athletes. No studies have demonstrated a positive effect of IGF-I on physical performance in healthy individuals but this has not yet been studied in appropriately designed trials. Two pharmaceutical preparations of IGF-I have recently become available for the treatment of growth disorders in children. This availability is likely to increase the prevalence of IGF-I abuse. Combining IGF-I with its binding protein IGFBP-3 in one preparation has the potential to reduce the side-effect profile but the adverse effects of long term IGF-I abuse are currently unknown. Detection of abuse with IGF-I is a major challenge for anti-doping authorities. It is extremely difficult to distinguish the exogenous recombinant form of the hormone from endogenously-produced IGF-I. One approach currently being investigated is based on measuring markers of GH and IGF-I action. This has already proved successful in the fight against GH abuse and, it is hoped, will subsequently lead to a similar test for detection of IGF-I abuse.

  5. Insulin-like growth factors (IGFs) as autocrine/paracrine regulators of granulosa cell differentiation and growth: Studies with a neutralizing monoclonal antibody to IGF-I

    International Nuclear Information System (INIS)

    Mondschein, J.S.; Canning, S.F.; Miller, D.Q.; Hammond, J.M.

    1989-01-01

    Evidence that granulosa cells secrete and respond to insulin-like growth factors (IGFs) suggests, but does not prove, the importance of IGFs as intraovarian regulators. To further assess the role of these peptides in ovarian function, a neutralizing monoclonal antibody to IGF-I was employed to block the actions of IGFs in porcine follicular fluid and in granulosa cell-conditioned medium. In one series of experiments, granulosa cells from immature porcine follicles were cultured in medium containing porcine follicular fluid that had been charcoal-treated to remove steroids. As noted before, fluid from large follicles (LFF) stimulated progesterone production in a dose-dependent manner. The stimulatory effect of LFF (30% v/v) could be inhibited by greater than 50% by the anti-IGF monoclonal antibody. This inhibitory action was specific for the anti-IGF antibody and could be overcome by the addition of excess exogenous IGFs. In another series of experiments, granulosa cells were made dependent on endogenously produced IGFs by culturing them in a serum-free medium without exogenous growth factors. The effects of follicle-stimulating hormone (FSH), estradiol (E2), growth hormone (GH), and combinations thereof on progesterone production were inhibited by approximately 50% by the anti-IGF antibody. The effects of IGFs on indices of cell growth (judged by the criterion of being inhibited by the anti-IGF antibody) were less dramatic. A modest 18% increase in cell number was observed with FSH and E2 treatment in serum-free medium; this effect was virtually abolished by the antibody

  6. Insulin-like growth factors (IGFs) as autocrine/paracrine regulators of granulosa cell differentiation and growth: Studies with a neutralizing monoclonal antibody to IGF-I

    Energy Technology Data Exchange (ETDEWEB)

    Mondschein, J.S.; Canning, S.F.; Miller, D.Q.; Hammond, J.M. (Pennsylvania State Univ., Hershey (USA))

    1989-07-01

    Evidence that granulosa cells secrete and respond to insulin-like growth factors (IGFs) suggests, but does not prove, the importance of IGFs as intraovarian regulators. To further assess the role of these peptides in ovarian function, a neutralizing monoclonal antibody to IGF-I was employed to block the actions of IGFs in porcine follicular fluid and in granulosa cell-conditioned medium. In one series of experiments, granulosa cells from immature porcine follicles were cultured in medium containing porcine follicular fluid that had been charcoal-treated to remove steroids. As noted before, fluid from large follicles (LFF) stimulated progesterone production in a dose-dependent manner. The stimulatory effect of LFF (30% v/v) could be inhibited by greater than 50% by the anti-IGF monoclonal antibody. This inhibitory action was specific for the anti-IGF antibody and could be overcome by the addition of excess exogenous IGFs. In another series of experiments, granulosa cells were made dependent on endogenously produced IGFs by culturing them in a serum-free medium without exogenous growth factors. The effects of follicle-stimulating hormone (FSH), estradiol (E2), growth hormone (GH), and combinations thereof on progesterone production were inhibited by approximately 50% by the anti-IGF antibody. The effects of IGFs on indices of cell growth (judged by the criterion of being inhibited by the anti-IGF antibody) were less dramatic. A modest 18% increase in cell number was observed with FSH and E2 treatment in serum-free medium; this effect was virtually abolished by the antibody.

  7. Role of IGF-I in follistatin-induced skeletal muscle hypertrophy.

    Science.gov (United States)

    Barbé, Caroline; Kalista, Stéphanie; Loumaye, Audrey; Ritvos, Olli; Lause, Pascale; Ferracin, Benjamin; Thissen, Jean-Paul

    2015-09-15

    Follistatin, a physiological inhibitor of myostatin, induces a dramatic increase in skeletal muscle mass, requiring the type 1 IGF-I receptor/Akt/mTOR pathway. The aim of the present study was to investigate the role of IGF-I and insulin, two ligands of the IGF-I receptor, in the follistatin hypertrophic action on skeletal muscle. In a first step, we showed that follistatin increases muscle mass while being associated with a downregulation of muscle IGF-I expression. In addition, follistatin retained its full hypertrophic effect toward muscle in hypophysectomized animals despite very low concentrations of circulating and muscle IGF-I. Furthermore, follistatin did not increase muscle sensitivity to IGF-I in stimulating phosphorylation of Akt but, surprisingly, decreased it once hypertrophy was present. Taken together, these observations indicate that increased muscle IGF-I production or sensitivity does not contribute to the muscle hypertrophy caused by follistatin. Unlike low IGF-I, low insulin, as obtained by streptozotocin injection, attenuated the hypertrophic action of follistatin on skeletal muscle. Moreover, the full anabolic response to follistatin was restored in this condition by insulin but also by IGF-I infusion. Therefore, follistatin-induced muscle hypertrophy requires the activation of the insulin/IGF-I pathway by either insulin or IGF-I. When insulin or IGF-I alone is missing, follistatin retains its full anabolic effect, but when both are deficient, as in streptozotocin-treated animals, follistatin fails to stimulate muscle growth. Copyright © 2015 the American Physiological Society.

  8. IGF-I enhances cellular senescence via the reactive oxygen species-p53 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Handayaningsih, Anastasia-Evi; Takahashi, Michiko; Fukuoka, Hidenori; Iguchi, Genzo; Nishizawa, Hitoshi; Yamamoto, Masaaki; Suda, Kentaro [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Takahashi, Yutaka, E-mail: takahash@med.kobe-u.ac.jp [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Cellular senescence plays an important role in tumorigenesis and aging process. Black-Right-Pointing-Pointer We demonstrated IGF-I enhanced cellular senescence in primary confluent cells. Black-Right-Pointing-Pointer IGF-I enhanced cellular senescence in the ROS and p53-dependent manner. Black-Right-Pointing-Pointer These results may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging. -- Abstract: Cellular senescence is characterized by growth arrest, enlarged and flattened cell morphology, the expression of senescence-associated {beta}-galactosidase (SA-{beta}-gal), and by activation of tumor suppressor networks. Insulin-like growth factor-I (IGF-I) plays a critical role in cellular growth, proliferation, tumorigenesis, and regulation of aging. In the present study, we show that IGF-I enhances cellular senescence in mouse, rat, and human primary cells in the confluent state. IGF-I induced expression of a DNA damage marker, {gamma}H2AX, the increased levels of p53 and p21 proteins, and activated SA-{beta}-gal. In the confluent state, an altered downstream signaling of IGF-I receptor was observed. Treatment with a reactive oxygen species (ROS) scavenger, N-acetylcystein (NAC) significantly suppressed induction of these markers, indicating that ROS are involved in the induction of cellular senescence by IGF-I. In p53-null mouse embryonic fibroblasts, the IGF-I-induced augmentation of SA-{beta}-gal and p21 was inhibited, demonstrating that p53 is required for cellular senescence induced by IGF-I. Thus, these data reveal a novel pathway whereby IGF-I enhances cellular senescence in the ROS and p53-dependent manner and may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging.

  9. IGF-I enhances cellular senescence via the reactive oxygen species–p53 pathway

    International Nuclear Information System (INIS)

    Handayaningsih, Anastasia-Evi; Takahashi, Michiko; Fukuoka, Hidenori; Iguchi, Genzo; Nishizawa, Hitoshi; Yamamoto, Masaaki; Suda, Kentaro; Takahashi, Yutaka

    2012-01-01

    Highlights: ► Cellular senescence plays an important role in tumorigenesis and aging process. ► We demonstrated IGF-I enhanced cellular senescence in primary confluent cells. ► IGF-I enhanced cellular senescence in the ROS and p53-dependent manner. ► These results may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging. -- Abstract: Cellular senescence is characterized by growth arrest, enlarged and flattened cell morphology, the expression of senescence-associated β-galactosidase (SA-β-gal), and by activation of tumor suppressor networks. Insulin-like growth factor-I (IGF-I) plays a critical role in cellular growth, proliferation, tumorigenesis, and regulation of aging. In the present study, we show that IGF-I enhances cellular senescence in mouse, rat, and human primary cells in the confluent state. IGF-I induced expression of a DNA damage marker, γH2AX, the increased levels of p53 and p21 proteins, and activated SA-β-gal. In the confluent state, an altered downstream signaling of IGF-I receptor was observed. Treatment with a reactive oxygen species (ROS) scavenger, N-acetylcystein (NAC) significantly suppressed induction of these markers, indicating that ROS are involved in the induction of cellular senescence by IGF-I. In p53-null mouse embryonic fibroblasts, the IGF-I-induced augmentation of SA-β-gal and p21 was inhibited, demonstrating that p53 is required for cellular senescence induced by IGF-I. Thus, these data reveal a novel pathway whereby IGF-I enhances cellular senescence in the ROS and p53-dependent manner and may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging.

  10. GH/IGF-I axis and matrix adaptation of the musculotendinous tissue to exercise in humans

    DEFF Research Database (Denmark)

    Heinemeier, K M; Mackey, Abigail; Doessing, S

    2012-01-01

    cells (satellite cells), as increased satellite cell numbers are found in human muscle with increased GH/IGF-I levels, despite no change in myofibrillar protein synthesis. Although advanced age is associated with both a reduction in the GH/IGF-I axis activity, and in skeletal muscle mass (sarcopenia...

  11. Structural analysis of the interaction of IGF I with the IGF types 1 and 2 and insulin receptors

    International Nuclear Information System (INIS)

    Cascieri, M.A.; Chicchi, G.G.; Hayes, N.S.; Green, B.G.; Applebaum, J.A.; Bayne, M.L.

    1987-01-01

    A synthetic gene for human IGF I has been synthesized which directs the synthesis and secretion of fully active human IGF I (rIGF I) from yeast. rIGF I inhibits binding of 125 I-IGF I to type 1 IGF receptors from human placenta (IGF-R1, IC50 = 4 nM), binding of 125 I-insulin to insulin receptors (IR, IC50 = 881 nM), binding of 125 I-MSA to type 2 IGF receptors from rat liver (IGF-R2, IC50 = 80 nM), and binding of 125 I-IGF I to crude human serum binding protein (hBP, IC50 = 0.42 nM). rIGF I is equipotent to human IGF I in stimulating glucose transport in murine BC3H1 cells and in stimulating DNA synthesis in rat A10 cells. Site directed mutagenesis of the synthetic gene is being used to characterize the structural requirements for binding to these receptors. IGF I (FFY) B(23-25) is equipotent to rIGF I at the IGF-R1 (6.9 nM), the IGF-R2 (36 nM), and the IR (841 nM) and is less potent at the hBP (1.7 nM). In contrast, IGF I(SFY) B(23-25) is 20-fold less potent than rIGF I at the IGF-R1 and is 10-fold less potent than rIGF I at hBP. This peptide is greater than 10-fold less active at the IGF-R2 and the IR. This peptide is a full agonist in the cell assays but 20-50 fold less potent than rIGF I. These data are consistent with the hypothesis that the F to S change destabilizes the tertiary structure of IGF I

  12. Circulating IGF-I and IGFBP3 levels control human colonic stem cell function and are disrupted in diabetic enteropathy

    Science.gov (United States)

    Maestroni, Anna; Jung, Peter; Orsenigo, Elena; Nasr, Moufida Ben; Tezza, Sara; Bassi, Roberto; Finzi, Giovanna; Marando, Alessandro; Vergani, Andrea; Frego, Roberto; Albarello, Luca; Andolfo, Annapaola; Manuguerra, Roberta; Viale, Edi; Staudacher, Carlo; Corradi, Domenico; Batlle, Eduard; Breault, David; Secchi, Antonio; Folli, Franco; Fiorina, Paolo

    2016-01-01

    Summary The role of circulating factors in regulating colonic stem cells (CoSCs) and colonic epithelial homeostasis is unclear. Individuals with long-standing type 1 diabetes (T1D) frequently have intestinal symptoms, termed diabetic enteropathy (DE), though its etiology is unknown. Here, we report T1D patients with DE exhibit abnormalities in their intestinal mucosa and CoSCs, which fail to generate in vitro mini-guts. Proteomic profiling of T1D+DE patient serum revealed altered levels of insulin-like growth factor 1 (IGF-1) and its binding protein-3 (IGFBP3). IGFBP3 prevented in vitro growth of patient-derived organoids via binding its receptor TMEM219, in an IGF-1-independent manner, and disrupted in vivo CoSC function in a preclinical DE model. Restoration of normoglycemia in patients with long-standing T1D via kidney-pancreas transplantation or in diabetic mice by treatment with an ecto-TMEM219 recombinant protein normalized circulating IGF-1/IGFBP3 levels and reestablished CoSC homeostasis. These findings demonstrate that peripheral IGF-1/IGFBP3 control CoSCs and their dysfunction in DE. PMID:26431183

  13. Monoclonal antibodies directed to human insulin-like growth factor I (IGF I)

    International Nuclear Information System (INIS)

    Laubli, U.K.; Baier, W.; Celio, M.R.; Binz, H.; Humbel, R.E.

    1982-01-01

    Mouse hybridomas secreting antibodies to human insulin-like growth factor I (IGF I) were produced by fusion of spleen cells of hyperimmunised mice with FO mouse-myeloma cells. Eight clones producing antibodies against human IGF I have been isolated, two of which have been characterised. One was used in a radioimmunoassay, the other for immunopurification of IGF. (Auth.)

  14. Regulation of insulin-like growth factor (IGF) I receptor expression during muscle cell differentiation. Potential autocrine role of IGF-II.

    OpenAIRE

    Rosenthal, S M; Brunetti, A; Brown, E J; Mamula, P W; Goldfine, I D

    1991-01-01

    Muscle is an important target tissue for insulin-like growth factor (IGF) action. The presence of specific, high affinity IGF receptors, as well as the expression of IGF peptides and binding proteins by muscle suggest that a significant component of IGF action in this tissue is mediated through autocrine and/or paracrine mechanisms. To explore autocrine/paracrine action of IGFs in muscle, we studied the regulation of the IGF-I receptor and the expression of IGF peptides during differentiation...

  15. Deficiency of liver-derived insulin-like growth factor-I (IGF-I) does not interfere with the skin wound healing rate

    Science.gov (United States)

    Narayanan, Sampath; Grünler, Jacob; Sunkari, Vivekananda Gupta; Calissendorff, Freja S.; Ansurudeen, Ishrath; Illies, Christopher; Svensson, Johan; Jansson, John-Olov; Ohlsson, Claes; Brismar, Kerstin; Catrina, Sergiu-Bogdan

    2018-01-01

    Objective IGF-I is a growth factor, which is expressed in virtually all tissues. The circulating IGF-I is however derived mainly from the liver. IGF-I promotes wound healing and its levels are decreased in wounds with low regenerative potential such as diabetic wounds. However, the contribution of circulating IGF-I to wound healing is unknown. Here we investigated the role of systemic IGF-I on wound healing rate in mice with deficiency of liver-derived IGF-I (LI-IGF-I-/- mice) during normal (normoglycemic) and impaired wound healing (diabetes). Methods LI-IGF-I-/- mice with complete inactivation of the IGF-I gene in the hepatocytes were generated using the Cre/loxP recombination system. This resulted in a 75% reduction of circulating IGF-I. Diabetes was induced with streptozocin in both LI-IGF-I-/- and control mice. Wounds were made on the dorsum of the mice, and the wound healing rate and histology were evaluated. Serum IGF-I and GH were measured by RIA and ELISA respectively. The expression of IGF-I, IGF-II and the IGF-I receptor in the skin were evaluated by qRT-PCR. The local IGF-I protein expression in different cell types of the wounds during wound healing process was analyzed using immunohistochemistry. Results The wound healing rate was similar in LI-IGF-I-/- mice to that in controls. Diabetes significantly delayed the wound healing rate in both LI-IGF-I-/- and control mice. However, no significant difference was observed between diabetic animals with normal or reduced hepatic IGF-I production. The gene expression of IGF-I, IGF-II and IGF-I receptor in skin was not different between any group of animals tested. Local IGF-I levels in the wounds were similar between of LI-IGF-I-/- and WT mice although a transient reduction of IGF-I expression in leukocytes in the wounds of LI-IGF-I-/- was observed seven days post wounding. Conclusion Deficiency in the liver-derived IGF-I does not affect wound healing in mice, neither in normoglycemic conditions nor in

  16. Monoclonal antibody to the type I insulin-like growth factor (IGF-I) receptor blocks IGF-I receptor-mediated DNA synthesis: clarification of the mitogenic mechanisms of IGF-I and insulin in human skin fibroblasts

    International Nuclear Information System (INIS)

    Flier, J.S.; Usher, P.; Moses, A.C.

    1986-01-01

    Insulin and insulin-like growth factor type I (IGF-I) stimulate an overlapping spectrum of biological responses in human skin fibroblasts. Although insulin and IGF-I are known to stimulate the incorporation of [ 3 H]thymidine into DNA in these cells, the identify of the receptor(s) that mediates this effect has not been fully clarified. The mouse anti-human IGF-I receptor antibody αIR-3 binds with specificity to IGF-I but not to insulin receptors in human placental membranes; it also specifically inhibits the binding of 125 I-labeled IGF-I but not 125 I-labeled insulin to suspensions of human skin fibroblasts in a dose-dependent manner. αIR-3 competitively inhibits IGF-I-mediated stimulation of [ 3 H]thymidine incorporation into DNA. This inhibition is dependent on the concentration of αIR-3 and in the presence of a fixed antibody concentration can be partially overcome by high concentrations of IGF-I. In contrast, at concentrations of 3 H]thymidine incorporation is not inhibited by αIR-3. However, the incremental effects of higher concentrations (> 1 μg/ml) of insulin on [ 3 H]thymidine incorporation are inhibited by αIR-3. αIR-3 is a highly specific antagonist of IGF-I receptor-mediated mitogenesis in human skin fibroblasts. By using this antibody, it is shown directly that insulin can act through the IGF-I receptor to stimulate DNA synthesis but can also activate this effect through the insulin receptor itself

  17. Androgen receptor activation integrates complex transcriptional effects in osteoblasts, involving the growth factors TGF-β and IGF-I, and transcription factor C/EBPδ.

    Science.gov (United States)

    McCarthy, Thomas L; Centrella, Michael

    2015-11-15

    Osteoblasts respond to many growth factors including IGF-I and TGF-β, which themselves are sensitive to other bone growth regulators. Here we show that IGF-I gene promoter activity in prostaglandin E2 (PGE2) induced osteoblasts is suppressed by dihydrotestosterone (DHT) through an essential C/EBP response element (RE) in exon 1 of the igf1 gene. Inhibition by DHT fails to occur when the androgen receptor (AR) gene is mutated within its DNA binding domain. Correspondingly, DHT activated AR inhibits gene transactivation by C/EBPδ, and transgenic C/EBPδ expression inhibits AR activity. Inhibition by DHT persists when upstream Smad and Runx REs in the IGF-I gene promoter are mutated. TGF-β also enhances IGF-I gene promoter activity, although modestly relative to PGE2, and independently of the C/EBP, Smad, or Runx REs. Still, DHT suppresses TGF-β induced IGF-I promoter activity, but not its effects on DNA or collagen synthesis. Notably, DHT suppresses plasminogen activator inhibitor gene promoter activity, but synergistically increases Smad dependent gene promoter activity in TGF-β induced cells, which are differentially sensitive to AR mutations and the AR co-regulator ARA55. Finally, although the PGE2 sensitive C/EBP RE in the igf1 gene is not essential for basal TGF-β induction, C/EBPδ activity through this site is potently enhanced by TGF-β. Thus DHT suppresses the PGE2 and TGF-β induced IGF-I gene promoter and differentiates other aspects of TGF-β activity in osteoblasts. Our results extend the complex interactions among local and systemic bone growth regulators to DHT, and predict complications from anabolic steroid use in other DHT sensitive tissues. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Endocrine and Local IGF-I in the Bony Fish Immune System.

    Science.gov (United States)

    Franz, Anne-Constance; Faass, Oliver; Köllner, Bernd; Shved, Natallia; Link, Karl; Casanova, Ayako; Wenger, Michael; D'Cotta, Helena; Baroiller, Jean-François; Ullrich, Oliver; Reinecke, Manfred; Eppler, Elisabeth

    2016-01-26

    A role for GH and IGF-I in the modulation of the immune system has been under discussion for decades. Generally, GH is considered a stimulator of innate immune parameters in mammals and teleost fish. The stimulatory effects in humans as well as in bony fish often appear to be correlated with elevated endocrine IGF-I (liver-derived), which has also been shown to be suppressed during infection in some studies. Nevertheless, data are still fragmentary. Some studies point to an important role of GH and IGF-I particularly during immune organ development and constitution. Even less is known about the potential relevance of local (autocrine/paracrine) IGF-I within adult and developing immune organs, and the distinct localization of IGF-I in immune cells and tissues of mammals and fish has not been systematically defined. Thus far, IGF-I has been localized in different mammalian immune cell types, particularly macrophages and granulocytes, and in supporting cells, but not in T-lymphocytes. In the present study, we detected IGF-I in phagocytic cells isolated from rainbow trout head kidney and, in contrast to some findings in mammals, in T-cells of a channel catfish cell line. Thus, although numerous analogies among mammals and teleosts exist not only for the GH/IGF-system, but also for the immune system, there are differences that should be further investigated. For instance, it is unclear whether the primarily reported role of GH/IGF-I in the innate immune response is due to the lack of studies focusing on the adaptive immune system, or whether it truly preferentially concerns innate immune parameters. Infectious challenges in combination with GH/IGF-I manipulations are another important topic that has not been sufficiently addressed to date, particularly with respect to developmental and environmental influences on fish growth and health.

  19. Endocrine and Local IGF-I in the Bony Fish Immune System

    Directory of Open Access Journals (Sweden)

    Anne-Constance Franz

    2016-01-01

    Full Text Available A role for GH and IGF-I in the modulation of the immune system has been under discussion for decades. Generally, GH is considered a stimulator of innate immune parameters in mammals and teleost fish. The stimulatory effects in humans as well as in bony fish often appear to be correlated with elevated endocrine IGF-I (liver-derived, which has also been shown to be suppressed during infection in some studies. Nevertheless, data are still fragmentary. Some studies point to an important role of GH and IGF-I particularly during immune organ development and constitution. Even less is known about the potential relevance of local (autocrine/paracrine IGF-I within adult and developing immune organs, and the distinct localization of IGF-I in immune cells and tissues of mammals and fish has not been systematically defined. Thus far, IGF-I has been localized in different mammalian immune cell types, particularly macrophages and granulocytes, and in supporting cells, but not in T-lymphocytes. In the present study, we detected IGF-I in phagocytic cells isolated from rainbow trout head kidney and, in contrast to some findings in mammals, in T-cells of a channel catfish cell line. Thus, although numerous analogies among mammals and teleosts exist not only for the GH/IGF-system, but also for the immune system, there are differences that should be further investigated. For instance, it is unclear whether the primarily reported role of GH/IGF-I in the innate immune response is due to the lack of studies focusing on the adaptive immune system, or whether it truly preferentially concerns innate immune parameters. Infectious challenges in combination with GH/IGF-I manipulations are another important topic that has not been sufficiently addressed to date, particularly with respect to developmental and environmental influences on fish growth and health.

  20. Human IGF-I propeptide A promotes articular chondrocyte biosynthesis and employs glycosylation-dependent heparin binding.

    Science.gov (United States)

    Shi, Shuiliang; Kelly, Brian J; Wang, Congrong; Klingler, Ken; Chan, Albert; Eckert, George J; Trippel, Stephen B

    2018-03-01

    Insulin-like growth factor I (IGF-I) is a key regulator of chondrogenesis, but its therapeutic application to articular cartilage damage is limited by rapid elimination from the repair site. The human IGF-I gene gives rise to three IGF-I propeptides (proIGF-IA, proIGF-IB and proIGF-IC) that are cleaved to create mature IGF-I. In this study, we elucidate the processing of IGF-I precursors by articular chondrocytes, and test the hypotheses that proIGF-I isoforms bind to heparin and regulate articular chondrocyte biosynthesis. Human IGF-I propeptides and mutants were overexpressed in bovine articular chondrocytes. IGF-I products were characterized by ELISA, western blot and FPLC using a heparin column. The biosynthetic activity of IGF-I products on articular chondrocytes was assayed for DNA and glycosaminoglycan that the cells produced. Secreted IGF-I propeptides stimulated articular chondrocyte biosynthetic activity to the same degree as mature IGF-I. Of the three IGF-I propeptides, only one, proIGF-IA, strongly bound to heparin. Interestingly, heparin binding of proIGF-IA depended on N-glycosylation at Asn92 in the EA peptide. To our knowledge, this is the first demonstration that N-glycosylation determines the binding of a heparin-binding protein to heparin. The biosynthetic and heparin binding abilities of proIGF-IA, coupled with its generation of IGF-I, suggest that proIGF-IA may have therapeutic value for articular cartilage repair. These data identify human pro-insulin-like growth factor IA as a bifunctional protein. Its combined ability to bind heparin and augment chondrocyte biosynthesis makes it a promising therapeutic agent for cartilage damage due to trauma and osteoarthritis. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Accelerated Telomere Shortening in Acromegaly; IGF-I Induces Telomere Shortening and Cellular Senescence.

    Science.gov (United States)

    Matsumoto, Ryusaku; Fukuoka, Hidenori; Iguchi, Genzo; Odake, Yukiko; Yoshida, Kenichi; Bando, Hironori; Suda, Kentaro; Nishizawa, Hitoshi; Takahashi, Michiko; Yamada, Shozo; Ogawa, Wataru; Takahashi, Yutaka

    2015-01-01

    Patients with acromegaly exhibit reduced life expectancy and increased prevalence of age-related diseases, such as diabetes, hypertension, and cardiovascular disease. However, the underlying mechanism has not been fully elucidated. Telomere shortening is reportedly associated with reduced life expectancy and increased prevalence of these age-related diseases. We measured telomere length in patients with acromegaly using quantitative PCR method. The effect of GH and IGF-I on telomere length and cellular senescence was examined in human skin fibroblasts. Patients with acromegaly exhibited shorter telomere length than age-, sex-, smoking-, and diabetes-matched control patients with non-functioning pituitary adenoma (0.62 ± 0.23 vs. 0.75 ± 0.35, respectively, P = 0.047). In addition, telomere length in acromegaly was negatively correlated with the disease duration (R2 = 0.210, P = 0.003). In vitro analysis revealed that not GH but IGF-I induced telomere shortening in human skin fibroblasts. Furthermore, IGF-I-treated cells showed increased senescence-associated β-galactosidase activity and expression of p53 and p21 protein. IGF-I-treated cells reached the Hayflick limit earlier than GH- or vehicle-treated cells, indicating that IGF-I induces cellular senescence. Shortened telomeres in acromegaly and cellular senescence induced by IGF-I can explain, in part, the underlying mechanisms by which acromegaly exhibits an increased morbidity and mortality in association with the excess secretion of IGF-I.

  2. Compensatory growth assessment by plasma IGF-I hormone ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... feeding diets and regimes will be evaluated in future studies. Key words: Compensatory growth, food coefficient ratio, food intake, IGF-I, rainbow trout, special growth .... Blood was sampled for IGF-I hormone concentration.

  3. Bone Growth Mechanical Stimulus and IGF-I

    National Research Council Canada - National Science Library

    Gilsanz, Vicente

    2003-01-01

    .... This study also examines the possible relations between the cross-sectional properties of bone and circulating levels of IGF-I, IGF-binding protein-3, and IGF-I genotypes in teenagers ages 15 to 20...

  4. Bone Growth, Mechanical Stimulus and IGF-I

    National Research Council Canada - National Science Library

    Gilsanz, Vicente

    2002-01-01

    ... exercise intervention or no intervention. This study also examines the possible relations between the cross-sectional properties of bone and circulating levels of IGF-I, JGF-binding protein-3, and IGF-I genotypes in teenagers...

  5. Overexpression of insulin-like growth factor (IGF)-I receptor enhances inhibition of DNA replication in mouse cells exposed to x-rays

    International Nuclear Information System (INIS)

    Wang, Y.; Cheong, N.; Miura, M.; Iliakis, G.

    1997-01-01

    Previous studies from our laboratory provided evidence for the operation of signal transduction pathways involving ras, myc, and staurosporine-sensitive protein kinases in the regulation of DNA replication in irradiated cells. Because ras and myc are also involved in the signal transduction elicited in response to ligand activation of growth factor receptors, we wondered whether growth factor receptors are upstream elements in the regulation of DNA replication in irradiated cells. Here, we report on the role of insulin-like growth factor I receptor (IGF-IR) in the regulation of DNA replication in irradiated cells. We compare radiation-induced inhibition of DNA replication in BALB/c 3T3 cells with that in P6 cells. P6 cells are derived from BALB/c 3T3 cells by transfection with a vector expressing IGF-IR, leading to 30-fold overexpression. We observe a significantly stronger inhibition of DNA replication after irradiation in P6 as compared with BALB/c 3T3 cells at all doses examined. Sedimentation in alkaline sucrose gradients shows that the increased inhibition in P6 cells is due to an increased inhibition of replicon initiation, the main controlling event in DNA replication. Staurosporine at 20 nM reduces radiation-induced inhibition of DNA replication in BALB/c 3T3 cells, but has only a small effect in P6 cells. Caffeine at a concentration of 1 mM, on the other hand, removes over 60% of the inhibition in both cell lines. The results implicate IGF-IR in the regulation of DNA replication in irradiated cells, but also suggest differences between cells of different origins in the proteins involved in the regulating signal transduction pathway. (orig.). With 5 figs

  6. Regulation of human trophoblast GLUT1 glucose transporter by insulin-like growth factor I (IGF-I.

    Directory of Open Access Journals (Sweden)

    Marc U Baumann

    Full Text Available Glucose transport to the fetus across the placenta takes place via glucose transporters in the opposing faces of the barrier layer, the microvillous and basal membranes of the syncytiotrophoblast. While basal membrane content of the GLUT1 glucose transporter appears to be the rate-limiting step in transplacental transport, the factors regulating transporter expression and activity are largely unknown. In view of the many studies showing an association between IGF-I and fetal growth, we investigated the effects of IGF-I on placental glucose transport and GLUT1 transporter expression. Treatment of BeWo choriocarcinoma cells with IGF-I increased cellular GLUT1 protein. There was increased basolateral (but not microvillous uptake of glucose and increased transepithelial transport of glucose across the BeWo monolayer. Primary syncytial cells treated with IGF-I also demonstrated an increase in GLUT1 protein. Term placental explants treated with IGF-I showed an increase in syncytial basal membrane GLUT1 but microvillous membrane GLUT1 was not affected. The placental dual perfusion model was used to assess the effects of fetally perfused IGF-I on transplacental glucose transport and syncytial GLUT1 content. In control perfusions there was a decrease in transplacental glucose transport over the course of the perfusion, whereas in tissues perfused with IGF-I through the fetal circulation there was no change. Syncytial basal membranes from IGF-I perfused tissues showed an increase in GLUT1 content. These results demonstrate that IGF-I, whether acting via microvillous or basal membrane receptors, increases the basal membrane content of GLUT1 and up-regulates basal membrane transport of glucose, leading to increased transepithelial glucose transport. These observations provide a partial explanation for the mechanism by which IGF-I controls nutrient supply in the regulation of fetal growth.

  7. Systemic administration of IGF-I enhances healing in collagenous extracellular matrices: evaluation of loaded and unloaded ligaments

    Science.gov (United States)

    Provenzano, Paolo P; Alejandro-Osorio, Adriana L; Grorud, Kelley W; Martinez, Daniel A; Vailas, Arthur C; Grindeland, Richard E; Vanderby, Ray

    2007-01-01

    Background Insulin-like growth factor-I (IGF-I) plays a crucial role in wound healing and tissue repair. We tested the hypotheses that systemic administration of IGF-I, or growth hormone (GH), or both (GH+IGF-I) would improve healing in collagenous connective tissue, such as ligament. These hypotheses were examined in rats that were allowed unrestricted activity after injury and in animals that were subjected to hindlimb disuse. Male rats were assigned to three groups: ambulatory sham-control, ambulatory-healing, and hindlimb unloaded-healing. Ambulatory and hindlimb unloaded animals underwent surgical disruption of their knee medial collateral ligaments (MCLs), while sham surgeries were performed on control animals. Healing animals subcutaneously received systemic doses of either saline, GH, IGF-I, or GH+IGF-I. After 3 weeks, mechanical properties, cell and matrix morphology, and biochemical composition were examined in control and healing ligaments. Results Tissues from ambulatory animals receiving only saline had significantly greater strength than tissue from saline receiving hindlimb unloaded animals. Addition of IGF-I significantly improved maximum force and ultimate stress in tissues from both ambulatory and hindlimb unloaded animals with significant increases in matrix organization and type-I collagen expression. Addition of GH alone did not have a significant effect on either group, while addition of GH+IGF-I significantly improved force, stress, and modulus values in MCLs from hindlimb unloaded animals. Force, stress, and modulus values in tissues from hindlimb unloaded animals receiving IGF-I or GH+IGF-I exceeded (or were equivalent to) values in tissues from ambulatory animals receiving only saline with greatly improved structural organization and significantly increased type-I collagen expression. Furthermore, levels of IGF-receptor were significantly increased in tissues from hindlimb unloaded animals treated with IGF-I. Conclusion These results

  8. Systemic administration of IGF-I enhances healing in collagenous extracellular matrices: evaluation of loaded and unloaded ligaments

    Directory of Open Access Journals (Sweden)

    Martinez Daniel A

    2007-03-01

    Full Text Available Abstract Background Insulin-like growth factor-I (IGF-I plays a crucial role in wound healing and tissue repair. We tested the hypotheses that systemic administration of IGF-I, or growth hormone (GH, or both (GH+IGF-I would improve healing in collagenous connective tissue, such as ligament. These hypotheses were examined in rats that were allowed unrestricted activity after injury and in animals that were subjected to hindlimb disuse. Male rats were assigned to three groups: ambulatory sham-control, ambulatory-healing, and hindlimb unloaded-healing. Ambulatory and hindlimb unloaded animals underwent surgical disruption of their knee medial collateral ligaments (MCLs, while sham surgeries were performed on control animals. Healing animals subcutaneously received systemic doses of either saline, GH, IGF-I, or GH+IGF-I. After 3 weeks, mechanical properties, cell and matrix morphology, and biochemical composition were examined in control and healing ligaments. Results Tissues from ambulatory animals receiving only saline had significantly greater strength than tissue from saline receiving hindlimb unloaded animals. Addition of IGF-I significantly improved maximum force and ultimate stress in tissues from both ambulatory and hindlimb unloaded animals with significant increases in matrix organization and type-I collagen expression. Addition of GH alone did not have a significant effect on either group, while addition of GH+IGF-I significantly improved force, stress, and modulus values in MCLs from hindlimb unloaded animals. Force, stress, and modulus values in tissues from hindlimb unloaded animals receiving IGF-I or GH+IGF-I exceeded (or were equivalent to values in tissues from ambulatory animals receiving only saline with greatly improved structural organization and significantly increased type-I collagen expression. Furthermore, levels of IGF-receptor were significantly increased in tissues from hindlimb unloaded animals treated with IGF-I

  9. Accelerated Telomere Shortening in Acromegaly; IGF-I Induces Telomere Shortening and Cellular Senescence

    Science.gov (United States)

    Matsumoto, Ryusaku; Fukuoka, Hidenori; Iguchi, Genzo; Odake, Yukiko; Yoshida, Kenichi; Bando, Hironori; Suda, Kentaro; Nishizawa, Hitoshi; Takahashi, Michiko; Yamada, Shozo; Ogawa, Wataru; Takahashi, Yutaka

    2015-01-01

    Objective Patients with acromegaly exhibit reduced life expectancy and increased prevalence of age-related diseases, such as diabetes, hypertension, and cardiovascular disease. However, the underlying mechanism has not been fully elucidated. Telomere shortening is reportedly associated with reduced life expectancy and increased prevalence of these age-related diseases. Methods We measured telomere length in patients with acromegaly using quantitative PCR method. The effect of GH and IGF-I on telomere length and cellular senescence was examined in human skin fibroblasts. Results Patients with acromegaly exhibited shorter telomere length than age-, sex-, smoking-, and diabetes-matched control patients with non-functioning pituitary adenoma (0.62 ± 0.23 vs. 0.75 ± 0.35, respectively, P = 0.047). In addition, telomere length in acromegaly was negatively correlated with the disease duration (R 2 = 0.210, P = 0.003). In vitro analysis revealed that not GH but IGF-I induced telomere shortening in human skin fibroblasts. Furthermore, IGF-I-treated cells showed increased senescence-associated β-galactosidase activity and expression of p53 and p21 protein. IGF-I-treated cells reached the Hayflick limit earlier than GH- or vehicle-treated cells, indicating that IGF-I induces cellular senescence. Conclusion Shortened telomeres in acromegaly and cellular senescence induced by IGF-I can explain, in part, the underlying mechanisms by which acromegaly exhibits an increased morbidity and mortality in association with the excess secretion of IGF-I. PMID:26448623

  10. Accelerated Telomere Shortening in Acromegaly; IGF-I Induces Telomere Shortening and Cellular Senescence.

    Directory of Open Access Journals (Sweden)

    Ryusaku Matsumoto

    Full Text Available Patients with acromegaly exhibit reduced life expectancy and increased prevalence of age-related diseases, such as diabetes, hypertension, and cardiovascular disease. However, the underlying mechanism has not been fully elucidated. Telomere shortening is reportedly associated with reduced life expectancy and increased prevalence of these age-related diseases.We measured telomere length in patients with acromegaly using quantitative PCR method. The effect of GH and IGF-I on telomere length and cellular senescence was examined in human skin fibroblasts.Patients with acromegaly exhibited shorter telomere length than age-, sex-, smoking-, and diabetes-matched control patients with non-functioning pituitary adenoma (0.62 ± 0.23 vs. 0.75 ± 0.35, respectively, P = 0.047. In addition, telomere length in acromegaly was negatively correlated with the disease duration (R2 = 0.210, P = 0.003. In vitro analysis revealed that not GH but IGF-I induced telomere shortening in human skin fibroblasts. Furthermore, IGF-I-treated cells showed increased senescence-associated β-galactosidase activity and expression of p53 and p21 protein. IGF-I-treated cells reached the Hayflick limit earlier than GH- or vehicle-treated cells, indicating that IGF-I induces cellular senescence.Shortened telomeres in acromegaly and cellular senescence induced by IGF-I can explain, in part, the underlying mechanisms by which acromegaly exhibits an increased morbidity and mortality in association with the excess secretion of IGF-I.

  11. A low-fat, whole-food vegan diet, as well as other strategies that down-regulate IGF-I activity, may slow the human aging process.

    Science.gov (United States)

    McCarty, Mark F

    2003-06-01

    A considerable amount of evidence is consistent with the proposition that systemic IGF-I activity acts as pacesetter in the aging process. A reduction in IGF-I activity is the common characteristic of rodents whose maximal lifespan has been increased by a wide range of genetic or dietary measures, including caloric restriction. The lifespans of breeds of dogs and strains of rats tend to be inversely proportional to their mature weight and IGF-I levels. The link between IGF-I and aging appears to be evolutionarily conserved; in worms and flies, lifespan is increased by reduction-of-function mutations in signaling intermediates homologous to those which mediate insulin/IGF-I activity in mammals. The fact that an increase in IGF-I activity plays a key role in the induction of sexual maturity, is consistent with a broader role for-IGF-I in aging regulation. If down-regulation of IGF-I activity could indeed slow aging in humans, a range of practical measures for achieving this may be at hand. These include a low-fat, whole-food, vegan diet, exercise training, soluble fiber, insulin sensitizers, appetite suppressants, and agents such as flax lignans, oral estrogen, or tamoxifen that decrease hepatic synthesis of IGF-I. Many of these measures would also be expected to decrease risk for common age-related diseases. Regimens combining several of these approaches might have a sufficient impact on IGF-I activity to achieve a useful retardation of the aging process. However, in light of the fact that IGF-I promotes endothelial production of nitric oxide and may be of especial importance to cerebrovascular health, additional measures for stroke prevention-most notably salt restriction-may be advisable when attempting to down-regulate IGF-I activity as a pro-longevity strategy.

  12. Genetic influence on the associations between IGF-I and glucose metabolism in a cohort of elderly twins

    DEFF Research Database (Denmark)

    Jensen, Rikke Beck; Thankamony, Ajay; Holst, Klaus K.

    2018-01-01

    OBJECTIVE: IGF-I may be a marker of later metabolic and cardiovascular disease. The interactions between IGF-I and glucose metabolism are multifactorial, and there is potential confounding from several secondary effects. In this study, we examined the interaction between IGF-I and glucose...... metabolism in a large cohort of clinically well-characterized elderly twins. DESIGN: A total of 303 twin pairs of the same gender (606 twins) were included in the study; 125 monozygotic and 178 dizygotic twin pairs. METHODS: A clinical examination including a standard oral glucose tolerance test (OGTT.......11). In a multiple regression analysis (adjusting for age, gender and twin status), there was a negative association between IGF-I and insulin sensitivity (B: -0.13, SE 0.03, P cohort of 606 twins. The associations between IGF...

  13. Early programming of the IGF-I axis

    DEFF Research Database (Denmark)

    Larnkjær, Anni; Ingstrup, Helga Kristensen; Schack-Nielsen, Lene

    2009-01-01

    -I production. Conversely, studies suggest that later in childhood, those breastfed are taller and have higher IGF-I levels. Therefore, it has been suggested that the IGF-I axis may be programmed by diet during infancy. The association between IGF-I in infancy and later life is not known. OBJECTIVE: To examine...... for gender, breastfeeding, and other covariates. Likelihood ratio test based on residual log likelihood was applied for analysis including all measurements during infancy. RESULTS: There was an inverse association between IGF-I at 9 months and 17 years (r=-0.39, P=0.014, and n=40). A 1 ng/ml higher IGF...... covariates except IGF-I at 2 months which was significantly negatively associated with IGF-I at 17 years (P=0.030) corresponding to a 0.96 ng/ml lower IGF-I concentration at 17 years per ng/ml IGF-I at 2 months. Inclusion of all measurements during infancy showed a negative association with 17-year values (r...

  14. Low Circulating IGF-I Bioactivity in Elderly Men is associated with Increased Mortality

    NARCIS (Netherlands)

    M.P. Brugts (Michael); A.W. van den Beld (Annewieke); L.J. Hofland (Leo); K. van der Wansem (Katy); P.M. van Koetsveld (Peter); J. Frystyk (Jan); S.W.J. Lamberts (Steven); J.A.M.J.L. Janssen (Joseph)

    2008-01-01

    textabstractContext: Low IGF-I signaling activity prolongs lifespan in certain animal models, but the precise role of IGF-I in human survival remains controversial. The IGF-I kinase receptor activation assay (IGF-I KIRA) is a novel method for measuring IGF-I bioactivity in human serum. We

  15. Identification of Compounds That Inhibit IGF-I Signaling in Hyperglycemia

    Directory of Open Access Journals (Sweden)

    Laura A. Maile

    2009-01-01

    Full Text Available Increased responsiveness of vascular cells to the growth factor IGF-I has been implicated in complications associated with diabetes. Here we describe the development of an assay and screening of a library of compounds for their ability to accelerate cleavage of the transmembrane protein integrin-associated protein (IAP thereby disrupting the association between IAP and SHPS-1 which we have shown as critical for the enhanced response of vascular cells to IGF-I. The cell-based ELISA utilizes an antibody that specifically detects cleaved, but not intact, IAP. Of the 1040 compounds tested, 14 were considered active by virtue of their ability to stimulate an increase in antibody-binding indicative of IAP cleavage. In experiments with smooth muscle and retinal endothelial cell cultures in hyperglycemic conditions, each active compound was shown to accelerate the cleavage of IAP, and this was associated with a decrease in IAP association with SHPS-1 as determined by coimmunoprecipitation of the proteins from cell lysates. As a consequence of the acceleration in IAP cleavage, the compounds were shown to inhibit IGF-I-stimulated phosphorylation of key signaling molecules including Shc and ERK1/2, and this in turn was associated with a decrease in IGF-I-stimulated cell proliferation. Identification of these compounds that utilize this mechanism has the potential to yield novel therapeutic approaches for the prevention and treatment of vascular complications associated with diabetes.

  16. Role of IGF-I Signaling in Muscle Bone Interactions

    Science.gov (United States)

    Bikle, Daniel D; Tahimic, Candice; Chang, Wenhan; Wang, Yongmei; Philippou, Anastassios; Barton, Elisabeth R.

    2015-01-01

    Skeletal muscle and bone rely on a number of growth factors to undergo development, modulate growth, and maintain physiological strength. A major player in these actions is insulin-like growth factor I (IGF-I). However, because this growth factor can directly enhance muscle mass and bone density, it alters the state of the musculoskeletal system indirectly through mechanical crosstalk between these two organ systems. Thus, there are clearly synergistic actions of IGF-I that extend beyond the direct activity through its receptor. This review will cover the production and signaling of IGF-I as it pertains to muscle and bone, the chemical and mechanical influences that arise from IGF-I activity, and the potential for therapeutic strategies based on IGF-I. PMID:26453498

  17. [Differences in dynamics of insulin and insulin-like growth I (IGF-I) receptors internalization in isolated rat hepatocytes].

    Science.gov (United States)

    Kolychev, A P; Ternovskaya, E E; Arsenieva, A V; Shapkina, E V

    2013-01-01

    Insulin and IGF-I are two related peptides performing in the mammalian body functionally different roles of the metabolic and growth hormones, respectively. Internalization of the insulin-receptor complex (IRC) is the most important chain of mechanism of the action of hormone. To elucidate differences in the main stages of internalization of the two related hormones, the internalization dynamics of 125I-insulin and 125I-IGF-I was traced in isolated rat hepatocytes at 37 and 12 degrees C. There were established marked differences in the process of internalization of labeled hormones, which is stimulated by insulin and IGF-I. At 37 degrees C the insulin-stimulated internalization, unlike the process initiated by IGF-I, did not reach the maximal level for 1 h of incubation. However, essential differences in the internalization course of these two related peptide were obvious at the temperature of 12 degrees C. The internalization level of insulin receptors at 12 degrees C decreased by one third in spite of a significant increase of the insulin receptor binding on the hepatocytes plasma membrane. At 12 degrees C a slight decrease of the proportion of intracellular 125I-IGF-I correlated with a decrease in the 125I-IGF-I binding to receptors on the cell membrane. Internalization of IGF-I receptors was not affected by low temperature, as neither its level, nor the rate changed at 12 degrees C. The paradoxical decrease of the insulin-stimulated internalization at low temperature seems to represent a peculiar "inhibition mechanism" of immersion of IRC into the cell, which leads to accumulation of the complexes on the cell surface and possibly to a readjustment of the insulin biological activity. The resistance of internalization of the IGF-I receptor to cold seems to be related to the more ancient origin of this mechanism in the poikilothermal vertebrates.

  18. Detection of polymorphism of the insulin-like growth factor-I (IGF-I ...

    African Journals Online (AJOL)

    Molecular genetic selection on individual genes is a promising method to genetically improve economically important traits in chickens. The insulin-like growth factor-I (IGF-I) gene may play important roles in growth of multiple tissues, including muscle cells, cartilage and bone. In the present study, polymorphism of the ...

  19. AKT signaling mediates IGF-I survival actions on otic neural progenitors.

    Directory of Open Access Journals (Sweden)

    Maria R Aburto

    Full Text Available BACKGROUND: Otic neurons and sensory cells derive from common progenitors whose transition into mature cells requires the coordination of cell survival, proliferation and differentiation programmes. Neurotrophic support and survival of post-mitotic otic neurons have been intensively studied, but the bases underlying the regulation of programmed cell death in immature proliferative otic neuroblasts remains poorly understood. The protein kinase AKT acts as a node, playing a critical role in controlling cell survival and cell cycle progression. AKT is activated by trophic factors, including insulin-like growth factor I (IGF-I, through the generation of the lipidic second messenger phosphatidylinositol 3-phosphate by phosphatidylinositol 3-kinase (PI3K. Here we have investigated the role of IGF-dependent activation of the PI3K-AKT pathway in maintenance of otic neuroblasts. METHODOLOGY/PRINCIPAL FINDINGS: By using a combination of organotypic cultures of chicken (Gallus gallus otic vesicles and acoustic-vestibular ganglia, Western blotting, immunohistochemistry and in situ hybridization, we show that IGF-I-activation of AKT protects neural progenitors from programmed cell death. IGF-I maintains otic neuroblasts in an undifferentiated and proliferative state, which is characterised by the upregulation of the forkhead box M1 (FoxM1 transcription factor. By contrast, our results indicate that post-mitotic p27(Kip-positive neurons become IGF-I independent as they extend their neuronal processes. Neurons gradually reduce their expression of the Igf1r, while they increase that of the neurotrophin receptor, TrkC. CONCLUSIONS/SIGNIFICANCE: Proliferative otic neuroblasts are dependent on the activation of the PI3K-AKT pathway by IGF-I for survival during the otic neuronal progenitor phase of early inner ear development.

  20. Forkhead box A1 (FOXA1) is a key mediator of insulin-like growth factor I (IGF-I) activity.

    Science.gov (United States)

    Potter, Adam S; Casa, Angelo J; Lee, Adrian V

    2012-01-01

    The insulin-like growth factor receptor (IGF-IR) has been implicated in a number of human tumors, including breast cancer. Data from human breast tumors has demonstrated that IGF-IR is over-expressed and hyper-phosphorylated. Additionally, microarray analysis has shown that IGF-I treatment of MCF7 cells leads to a gene signature comprised of induced and repressed genes, which correlated with luminal B tumors. FOXA1, a forkhead family transcription factor, has been shown to be crucial for mammary ductal morphogenesis, similar to IGF-IR, and expressed at high levels in luminal subtype B breast tumors. Here, we investigated the relationship between FOXA1 and IGF-I action in breast cancer cells. We show that genes regulated by IGF-I are enriched for FOXA1 binding sites, and knock down of FOXA1 blocked the ability of IGF-I to regulate gene expression. IGF-I treatment of MCF7 cells increased the half-life of FOXA1 protein and this increase in half-life appeared to be dependent on canonical IGF-I signal transduction through both MAPK and AKT pathways. Finally, knock down of FOXA1 led to a decreased ability of IGF-I to induce proliferation and protect against apoptosis. Together, these results demonstrate that IGF-I can increase the stability of FOXA1 protein expression and place it as a critical mediator of IGF-I regulation of gene expression and IGF-I-mediated biological responses. Copyright © 2011 Wiley Periodicals, Inc.

  1. IGF-I and GH: potential use in gene doping.

    Science.gov (United States)

    Harridge, Stephen D R; Velloso, Cristiana P

    2009-08-01

    Gene doping is the term given to the potential misuse of gene therapy for the purposes of enhancing athletic performance. Insulin like growth factor-I (IGF-I), the prime target of growth hormone action, is one candidate gene for improving performance. In recent years a number of transgenic and somatic gene transfer studies on animals have shown that upregulation of IGF-I stimulates muscle growth and improves function. This increase in muscle IGF-I is not reflected in measurable increases in circulating IGF-I. Whilst the responses obtained in the animal studies would appear to give clear benefits for performance, the transfer of such techniques to humans still presents many technical challenges. Further challenges will also be faced by the anti doping authorities in detecting the endogenously produced products of enhanced gene expression.

  2. IGF-I and IGFBP2 in peripheral artery disease

    DEFF Research Database (Denmark)

    Urbonaviciene, Grazina; Frystyk, Jan; Urbonavicius, Sigitas

    2014-01-01

    BACKGROUND AND OBJECTIVES: The search for novel risk factors of cardiovascular disease (CVD) has provided valuable clinical data concerning underlying mechanism of disease. Increasing evidence indicates a possible involvement of insulin-like growth factor-I (IGF-I) and its binding protein 2 (IGFBP......-2) in the pathogenesis of CVD disorders. The aim of this study was to examine the relationship between levels of IGF-I and IGFBP-2 with all-cause and CVD mortality in a prospective study of patients with lower-extremity peripheral artery disease (PAD). METHODS AND MATERIAL: Serum IGF-I and IGFBP-2...... levels were obtained in 440 patients (257 males) with symptomatic PAD. Patients were followed for a median of 6.1 (IQ 5.1-7.2) years. The relationship between times to lethal outcome and baseline serum IGF-I and IFGBP-2 levels were examined by Cox proportional hazard analysis. The role of IFGBP-2...

  3. The Association Between IGF-I and Insulin Resistance

    DEFF Research Database (Denmark)

    Friedrich, Nele; Thuesen, Betina; Jørgensen, Torben

    2012-01-01

    OBJECTIVEIGF-I has an almost 50% amino acid sequence homology with insulin and elicits nearly the same hypoglycemic response. Studies showed that low and high IGF-I levels are related to impaired glucose tolerance and to a higher risk of type 2 diabetes. The aim of the current study was to evaluate...... the association between IGF-I level and insulin resistance in a Danish general population.RESEARCH DESIGN AND METHODSIncluded were 3,354 adults, aged 19-72 years, from the cross-sectional Health2006 study. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index to estimate insulin...... with intermediate (Q3) IGF-I levels. These associations remained statistically significant after the exclusion of subjects with type 2 diabetes and by using the updated computer HOMA2-IR model.CONCLUSIONSLow- and high-normal IGF-I levels are both related to insulin resistance. The biological mechanism...

  4. Validation of serum IGF-I as a biomarker to monitor the bioactivity of exogenous growth hormone agonists and antagonists in rabbits

    Science.gov (United States)

    Bielohuby, Maximilian; Zarkesh-Esfahani, Sayyed Hamid; Manolopoulou, Jenny; Wirthgen, Elisa; Walpurgis, Katja; Toghiany Khorasgani, Mohaddeseh; Aghili, Zahra Sadat; Wilkinson, Ian Robert; Hoeflich, Andreas; Thevis, Mario; Ross, Richard J.; Bidlingmaier, Martin

    2014-01-01

    The development of new growth hormone (GH) agonists and growth hormone antagonists (GHAs) requires animal models for pre-clinical testing. Ideally, the effects of treatment are monitored using the same pharmacodynamic marker that is later used in clinical practice. However, intact rodents are of limited value for this purpose because serum IGF-I, the most sensitive pharmacodynamic marker for the action of GH in humans, shows no response to treatment with recombinant human GH and there is little evidence for the effects of GHAs, except when administered at very high doses or when overexpressed. As an alternative, more suitable model, we explored pharmacodynamic markers of GH action in intact rabbits. We performed the first validation of an IGF-I assay for the analysis of rabbit serum and tested precision, sensitivity, linearity and recovery using an automated human IGF-I assay (IDS-iSYS). Furthermore, IGF-I was measured in rabbits of different strains, age groups and sexes, and we monitored IGF-I response to treatment with recombinant human GH or the GHA Pegvisomant. For a subset of samples, we used LC-MS/MS to measure IGF-I, and quantitative western ligand blot to analyze IGF-binding proteins (IGFBPs). Although recovery of recombinant rabbit IGF-I was only 50% in the human IGF-I assay, our results show that the sensitivity, precision (1.7–3.3% coefficient of variation) and linearity (90.4–105.6%) were excellent in rabbit samples. As expected, sex, age and genetic background were major determinants of IGF-I concentration in rabbits. IGF-I and IGFBP-2 levels increased after single and multiple injections of recombinant human GH (IGF-I: 286±22 versus 434±26 ng/ml; PIGF-I levels from the fourth injection onwards (PIGF-I immunoassay can be used in rabbits. Similar to rodents, rabbits display variations in IGF-I depending on sex, age and genetic background. Unlike in rodents, the IGF-I response to treatment with recombinant human GH or a GHA closely mimics the

  5. IGF-I: A key growth factor that regulates neurogenesis and synaptogenesis from embryonic to adult stages of the brain

    Directory of Open Access Journals (Sweden)

    Vanesa eNieto-Estévez

    2016-02-01

    Full Text Available The generation of neurons in the adult mammalian brain requires the activation of quiescent neural stem cells (NSCs. This activation and the sequential steps of neuron formation from NSCs are regulated by a number of stimuli, which include growth factors. Insulin-like growth factor-I (IGF-I exert pleiotropic effects, regulating multiple cellular processes depending on their concentration, cell type and the developmental stage of the animal. Although IGF-I expression is relatively high in the embryonic brain its levels drop sharply in the adult brain except in neurogenic regions, i.e., the hippocampus (HP and the subventricular zone-olfactory bulb (SVZ-OB. By contrast, the expression of IGF-IR remains relatively high in the brain irrespective of the age of the animal. Evidence indicates that IGF-I influences NSC proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. Furthermore, recent studies have shown that IGF-I not only promote adult neurogenesis by regulating NSC number and differentiation but also, by influencing neuronal positioning and migration as described during SVZ-OB neurogenesis. In this article we will revise and discuss the actions reported for IGF-I signaling in a variety of in vitro and in vivo models, focusing on the maintenance and proliferation of NSCs/progenitors, neurogenesis and neuron integration in synaptic circuits.

  6. IGF-I: A Key Growth Factor that Regulates Neurogenesis and Synaptogenesis from Embryonic to Adult Stages of the Brain

    Science.gov (United States)

    Nieto-Estévez, Vanesa; Defterali, Çağla; Vicario-Abejón, Carlos

    2016-01-01

    The generation of neurons in the adult mammalian brain requires the activation of quiescent neural stem cells (NSCs). This activation and the sequential steps of neuron formation from NSCs are regulated by a number of stimuli, which include growth factors. Insulin-like growth factor-I (IGF-I) exert pleiotropic effects, regulating multiple cellular processes depending on their concentration, cell type, and the developmental stage of the animal. Although IGF-I expression is relatively high in the embryonic brain its levels drop sharply in the adult brain except in neurogenic regions, i.e., the hippocampus (HP) and the subventricular zone-olfactory bulb (SVZ-OB). By contrast, the expression of IGF-IR remains relatively high in the brain irrespective of the age of the animal. Evidence indicates that IGF-I influences NSC proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. Furthermore, recent studies have shown that IGF-I not only promote adult neurogenesis by regulating NSC number and differentiation but also by influencing neuronal positioning and migration as described during SVZ-OB neurogenesis. In this article we will revise and discuss the actions reported for IGF-I signaling in a variety of in vitro and in vivo models, focusing on the maintenance and proliferation of NSCs/progenitors, neurogenesis, and neuron integration in synaptic circuits. PMID:26941597

  7. Normal Values of Circulating IGF-I Bioactivity in the Healthy Population: Comparison with five widely used IGF-I immunoassays

    NARCIS (Netherlands)

    M.P. Brugts (Michael); M.B. Ranke (Michael); L.J. Hofland (Leo); K. van der Wansem (Katy); K. Weber (Karin); J. Frystyk (Jan); S.W.J. Lamberts (Steven); J.A.M.J.L. Janssen (Joseph)

    2008-01-01

    textabstractBackground: IGF-I immunoassays are primarily used to estimate IGF-I bioactivity. Recently, an IGFI specific Kinase Receptor Activation Assay (KIRA) has been developed as an alternative method. However, no normative values have been established for the IGF-I KIRA. Objective: To

  8. Serum tree IGF-I, total IGF-I, IGFBP-1 and IGFBP-3 levels in an elderly population : relation to age and sex steroid levels

    NARCIS (Netherlands)

    Janssen, JAMJL; Stolk, RP; Pols, HAP; Grobbee, DE; de Jong, FH; Lamberts, SWJ

    BACKGROUND Most previous studies concerning the relationship between IGF-I and age used assays measuring total IGF-I, Although free IGF-I is considered of greater biological relevance, little is known about its relationship with sex steroids levels in elderly healthy subjects, MEASUREMENTS In a

  9. A polymorphism in the IGF-I gene influences the age-related decline in circulating total IGF-I levels

    NARCIS (Netherlands)

    I. Rietveld (Ingrid); J.A.M.J.L. Janssen (Joseph); A. Hofman (Albert); C.M. van Duijn (Cornelia); S.W.J. Lamberts (Steven); H.A.P. Pols (Huib)

    2003-01-01

    markdownabstractOBJECTIVE: Recent studies have demonstrated an association between a 192 bp polymorphism of the IGF-I gene and total IGF-I serum levels, birth weight, body height and the risk of developing diabetes and cardiovascular diseases later on in life. This IGF-I gene polymorphism in the

  10. Clinical significance of changes of serum Hcy and IGF-I levels after treatment in patients with acute cerebral infarction

    International Nuclear Information System (INIS)

    Wang Yuezhou

    2011-01-01

    Objective: To investigate the clinical significance of serum Hcy and IGF-I levels in patients with acute cerebral infarction. Methods: Serum IGF-I (with RIA), Hcy (with ELISA)levels were measured in 32 patients with acute cerebral infarction both before and after treatment as well as in 35 normal controls. Results: Before treatment, the serum Hcy level was remarkably higher than that in controls (P 0.05). Conclusion: The level of Hcy increased and IGF-I decreased in the patients with acute cerebral infarction which closely to the severity of acute cerebral infarction and may be taken as a sensitive biochemical indicator for predicting pathogenesis and progress of ACI. (authors)

  11. IGF-I replacement therapy in children with congenital IGF-I deficiency (Laron syndrome) maintains heart dimension and function.

    Science.gov (United States)

    Scheinowitz, Mickey; Feinberg, Micha S; Laron, Zvi

    2009-06-01

    Untreated patients with congenital growth hormone deficiency (GHD) and IGF-I deficiency are characterized not only by dwarfism but also by acromicria and organomicria, such as the heart. We assessed cardiac dimensions and function in very young patients with Laron syndrome (LS) undergoing IGF-I replacement therapy. Two to seven echocardiographic measurements were performed during IGF-I replacement therapy on male (n=4) and female (n=4) LS -patients, mean+/-SD age of 7.1+/-3.6 years (range 1.6-11.6 years), weight 16.1+/-9.7 kg, and height 89.9+/-18.5 cm. As aged- and gender-matched controls served 44 healthy children, age: 8.7+/-5.5 years, weight: 36.1+/-22.4 kg, and height: 129.7+/-33.1cm. Data of LS patients were normalized to body surface area and compared to the control group as well as nomograms of normal echocardiographic parameters for this age group. Left ventricular diastolic and systolic dimensions (LVDD/ LVSD, mm) and LV mass (gr) were significantly smaller in boys and girls with IGF-I treated LS compared with controls while the shortening fraction (%) and intraventricular septum thickness (mm) were similar. When compared with standard values for this age group, all treated LS patients were within 1 standard deviation of the mean. IGF-I therapy of young patients with Laron syndrome maintain LV dimensions and function within the normal range of aged-matched controls.

  12. Nutritional regulation of IGF-II, but not IGF-I, is age dependent in sheep.

    Science.gov (United States)

    Oldham, J M; Martyn, J A; Hua, K M; MacDonald, N A; Hodgkinson, S C; Bass, J J

    1999-12-01

    In post-natal animals, plasma concentrations of IGF-I are tightly regulated by nutritional status. The current study reports that plasma levels of IGF-II in sheep are also regulated by nutrition, but whether plasma IGF-II is increased, decreased or remains the same, depends on the age of the animal. Ewe lambs, ranging in age from 2 days to 2 years, were fed or fasted for lengths of time between 24 and 72 h. Blood samples were taken at intervals of 24 h throughout the treatment period and immediately before slaughter. Plasma concentrations of IGF-I increased with advancing age in fed animals (Panimals matured (Pnutrition (Panimals (Panimals (Pnutritional sensitivity of serum IGF-binding proteins (BPs) also changed with age. The 29 kDa BP, which we presume to be BP1, was elevated by fasting in young animals and reduced slightly in older animals. BP2 was increased to a similar magnitude by fasting at all ages. BP3 was depressed by fasting in young animals and showed little change in adults. In contrast, a 24 kDa BP, which is probably BP4, showed little change in young animals and was reduced substantially in older sheep. In conclusion, the response of plasma IGF-II to fasting suggests that this peptide has functions in mediating nutritional stress which depend on the age of the animal, and also that the role of IGF-II may differ from that of IGF-I in adults.

  13. IGF-I, IGF-II, and Insulin Stimulate Different Gene Expression Responses through Binding to the IGF-I Receptor

    DEFF Research Database (Denmark)

    Versteyhe, Soetkin; Klaproth, Birgit; Borup, Rehannah

    2013-01-01

    Insulin and the insulin-like growth factors (IGF)-I and -II are closely related peptides important for regulation of metabolism, growth, differentiation, and development. The IGFs exert their main effects through the IGF-I receptor. Although the insulin receptor is the main physiological receptor...... for insulin, this peptide hormone can also bind at higher concentrations to the IGF-I receptor and exert effects through it. We used microarray gene expression profiling to investigate the gene expression regulated by IGF-I, IGF-II, and insulin after stimulation of the IGF-I receptor. Fibroblasts from mice......, knockout for IGF-II and the IGF-II/cation-independent mannose-6-phosphate receptor, and expressing functional IGF-I but no insulin receptors, were stimulated for 4 h with equipotent saturating concentrations of insulin, IGF-I, and IGF-II. Each ligand specifically regulated a group of transcripts...

  14. Insulin Regulates Astrocytic Glucose Handling Through Cooperation With IGF-I.

    Science.gov (United States)

    Fernandez, Ana M; Hernandez-Garzón, Edwin; Perez-Domper, Paloma; Perez-Alvarez, Alberto; Mederos, Sara; Matsui, Takashi; Santi, Andrea; Trueba-Saiz, Angel; García-Guerra, Lucía; Pose-Utrilla, Julia; Fielitz, Jens; Olson, Eric N; Fernandez de la Rosa, Ruben; Garcia Garcia, Luis; Pozo, Miguel Angel; Iglesias, Teresa; Araque, Alfonso; Soya, Hideaki; Perea, Gertrudis; Martin, Eduardo D; Torres Aleman, Ignacio

    2017-01-01

    Brain activity requires a flux of glucose to active regions to sustain increased metabolic demands. Insulin, the main regulator of glucose handling in the body, has been traditionally considered not to intervene in this process. However, we now report that insulin modulates brain glucose metabolism by acting on astrocytes in concert with IGF-I. The cooperation of insulin and IGF-I is needed to recover neuronal activity after hypoglycemia. Analysis of underlying mechanisms show that the combined action of IGF-I and insulin synergistically stimulates a mitogen-activated protein kinase/protein kinase D pathway resulting in translocation of GLUT1 to the cell membrane through multiple protein-protein interactions involving the scaffolding protein GAIP-interacting protein C terminus and the GTPase RAC1. Our observations identify insulin-like peptides as physiological modulators of brain glucose handling, providing further support to consider the brain as a target organ in diabetes. © 2017 by the American Diabetes Association.

  15. Polymorphisms of genes coding for insulin-like growth factor 1 and its major binding proteins, circulating levels of IGF-I and IGFBP-3 and breast cancer risk: results from the EPIC study.

    NARCIS (Netherlands)

    Canzian, F; McKay, J D; Cleveland, R J; Dossus, Laure; Biessy, Carine; Rinaldi, Sabina; Landi, S; Boillot, C; Monnier, S; Chajès, V; Clavel-Chapelon, Françoise; Téhard, B; Chang-Claude, J; Linseisen, Jakob; Lahmann, Petra H; Pischon, Tobias; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Zilis, D; Palli, Domenico; Tumino, Rosario; Vineis, Paolo; Berrino, Franco; Bueno-de-Mesquita, H Bas; Gils, C H van; Peeters, Petra H M; Pera, Guillem; Ardanaz, Eva; Chirlaque, María-Dolores; Quirós, José Ramón; Larrañaga, Nerea; Martínez-García, Carmen; Allen, Naomi E; Key, Timothy J; Bingham, Sheila A; Khaw, Kay-Tee; Slimani, N; Norat, Teresa; Riboli, Elio; Kaaks, Rudolf

    2006-01-01

    Insulin-like growth factor I (IGF-I) stimulates cell proliferation and can enhance the development of tumours in different organs. Epidemiological studies have shown that an elevated level of circulating IGF-I is associated with increased risk of breast cancer, as well as of other cancers. Most of

  16. The role of the IGF axis in IGFBP-1 and IGF-I induced renal enlargement in Snell dwarf mice

    NARCIS (Netherlands)

    M. van Kleffens (Marjolein); D.J. Lindenbergh-Kortleve (Dicky); J.G. Koster; J.W. van Neck (Han); A. Flyvbjerg (Allan); R. Rasch; S.L.S. Drop (Stenvert); S.C. van Buul-Offers

    2001-01-01

    textabstractInsulin-like growth factor (IGF) binding protein-1 (IGFBP-1) is generally believed to inhibit IGF action in the circulation. In contrast, IGFBP-1 has been reported to interact with cell surfaces and enhance IGF-I action locally in some tissues. Renal IGFBP-1 levels are

  17. IGF-I stimulates ERβ and aromatase expression via IGF1R/PI3K/AKT-mediated transcriptional activation in endometriosis.

    Science.gov (United States)

    Zhou, Yan; Zeng, Cheng; Li, Xin; Wu, Pei-Li; Yin, Ling; Yu, Xiao-Lan; Zhou, Ying-Fang; Xue, Qing

    2016-08-01

    Estrogen receptor beta (ERβ, encoded by ESR2 gene) and cytochrome P450 aromatase (encoded by CYP19A1 gene) play critical roles in endometriosis, and the levels of insulin-like growth factor-I (IGF-I) in the peritoneal fluid are significantly higher in patients with endometriosis compared with those in normal women. However, the effects and mechanisms of IGF-I on ERβ and aromatase expression remain to be fully elucidated. In this study, human endometriotic stromal cells (ESCs) and endometrial cells (EMs) derived from ovarian endometriomas and eutopic endometrial tissues. ESCs were cultured with IGF-I, signal pathway inhibitors, and siRNAs. ERβ and aromatase expression were measured by real-time PCR and Western, respectively. The binding of c-Jun and CREB to the ESR2 and CYP19A1 promoters was assessed by chromatin immunoprecipitation assay. Animal experiments were performed in a xenograft mouse model. Levels of IGF-I mRNA in ESCs were markedly higher than those in EMs. IGF-I upregulated ERβ and aromatase expression in ESCs after stimulation of the IGF1R/PI3K/AKT pathway. Following IGF-I treatment, a marked increase in c-Jun and CREB phosphorylation occurred, enhancing binding to the ESR2 and CYP19A1 promoters. An IGF1R inhibitor in vivo reduced IGF-I-induced endometriosis graft growth and ERβ and aromatase expression. In conclusion, this is the first report to describe a mechanistic analysis of ERβ and aromatase expression regulated by IGF-I in ESCs. Moreover, an IGF1R inhibitor impeded ectopic lesion growth in nude mice. These findings suggest that an inhibitor of IGF1R might have therapeutic potential as an antiendometriotic drug. Level of IGF-I mRNA in ESCs is markedly higher than that in EMs. IGF-I up-regulates ERβ and aromatase expression via IGF1R/PI3K/AKT pathway. C-Jun and CREB are recruited to ESR2 or CYP19A1 promoter by IGF-I stimulation. IGF-1R inhibitors in vivo impede the growth of ectopic lesions in nude mice.

  18. Determination of LongR3-IGF-I, R3-IGF-I, Des1-3 IGF-I and their metabolites in human plasma samples by means of LC-MS.

    Science.gov (United States)

    Thomas, Andreas; Walpurgis, Katja; Delahaut, Philippe; Fichant, Eric; Schänzer, Wilhelm; Thevis, Mario

    2017-08-01

    According to the regulations of the World Anti-Doping Agency (WADA), growth promoting peptides such as the insulin-like growth factor-I (IGF-I) and its synthetic analogues belong to the class of prohibited compounds. While several assays to quantify endogenous IGF-I have been established, the potential misuse of synthetic analogues such as LongR 3 -IGF-I, R 3 -IGF-I and Des1-3-IGF-I remains a challenge and superior pharmacokinetic properties have been described for these analogues. Within the present study, it was demonstrated that the target peptides can be successfully detected in plasma samples by means of magnetic beads-based immunoaffinity purification and subsequent nanoscale liquid chromatographic separation with high resolution mass spectrometric detection. Noteworthy, the usage of a specific antibody for LongR 3 -IGF-I enables the determination in low ng/mL levels despite the presence of an enormous excess of endogenous human IGF-I. In addition, different metabolism studies (in-vitro and in-vivo) were performed using sophisticated strategies such as incubation with skin tissue microsomes, degradation in biological fluids (for all analogues), and administration to rats (for LongR 3 -IGF-I). Herewith, several C-and N-terminally truncated metabolites were identified and their relevancy was additionally confirmed by in-vivo experiments with rodents. Especially for LongR 3 -IGF-I, a metabolite ((Des1-11)-LongR 3 -IGF-I) was identified that prolonged the detectability in-vivo by a factor of approximately 2. The method was validated for qualitative interpretation considering the parameters specificity, identification capability, recovery (26-60%), limit of detection (0.5ng/mL), imprecision (IGF-I was used as internal standard to control all sample preparation steps. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. GH/IGF-I Transgene Expression on Muscle Homeostasis

    Science.gov (United States)

    Schwartz, Robert J.

    1999-01-01

    We propose to test the hypothesis that the growth hormone/ insulin like growth factor-I axis through autocrine/paracrine mechanisms may provide long term muscle homeostasis under conditions of prolonged weightlessness. As a key alternative to hormone replacement therapy, ectopic production of hGH, growth hormone releasing hormone (GHRH), and IGF-I will be studied for its potential on muscle mass impact in transgenic mice under simulated microgravity. Expression of either hGH or IGF-I would provide a chronic source of a growth-promoting protein whose biosynthesis or secretion is shut down in space. Muscle expression of the IGF-I transgene has demonstrated about a 20% increase in hind limb muscle mass over control nontransgenic litter mates. These recent experiments, also establish the utility of hind-limb suspension in mice as a workable model to study atrophy in weight bearing muscles. Thus, transgenic mice will be used in hind-limb suspension models to determine the role of GH/IGF-I on maintenance of muscle mass and whether concentric exercises might act in synergy with hormone treatment. As a means to engineer and ensure long-term protein production that would be workable in humans, gene therapy technology will be used by to monitor muscle mass preservation during hind-limb suspension, after direct intramuscular injection of a genetically engineered muscle-specific vector expressing GHRH. Effects of this gene-based therapy will be assessed in both fast twitch (medial gastrocnemius) and slow twitch muscle (soleus). End-points include muscle size, ultrastructure, fiber type, and contractile function, in normal animals, hind limb suspension, and reambutation.

  20. IGF-I and branchial IGF receptor expression and localization during salinity acclimation in striped bass

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbaek; Luckenbach, John Adam; Madsen, Steffen

    2007-01-01

    The initial response of the IGF-I system and the expression and cellular localization of IGF type-I receptor (IGF-IR) were studied in the gill of a euryhaline teleost during salinity acclimation. Exposure of striped bass (Morone saxatilis) to hyperosmotic and hypoosmotic challenges induced small...... in either plasma IGF-I, liver, or gill IGF-I mRNA, or gill IGF-IR mRNA levels. In a separate experiment, FW-acclimated fish were injected with saline or IGF-I prior to a 24-h SW challenge. Rapid regain of osmotic balance following SW transfer was hindered by IGF-I. Immunohistochemistry revealed...

  1. IGF-I bioactivity might reflect different aspects of quality of life than total IGF-I in gh-deficient patients during GH treatment

    NARCIS (Netherlands)

    A.J. Varewijck (Aimee); S.W.J. Lamberts (Steven); S.J.C.M.M. Neggers (Bas); L.J. Hofland (Leo); J.A.M.J.L. Janssen (Joseph)

    2013-01-01

    textabstractContext: No relationship has been found between improvement in quality of life (QOL) and total IGF-I during GH therapy. Aim: Our aim was to investigate the relationship between IGF-I bioactivity and QOL in GH-deficient (GHD) patients receiving GH for 12 months. Methods: Of 106 GHD

  2. Potency of full-length MGF to induce maximal activation of the IGF-I R Is similar to recombinant human IGF-I at high equimolar concentrations

    NARCIS (Netherlands)

    J.A.M.J.L. Janssen (Joseph); L.J. Hofland (Leo); C.J. Strasburger; E.S.R.D. Van Dungen (Elisabeth S.R. Den); M. Thevis (Mario)

    2016-01-01

    textabstractAims To compare full-length mechano growth factor (full-length MGF) with human recombinant insulin-like growth factor-I (IGF-I) and human recombinant insulin (HI) in their ability to activate the human IGF-I receptor (IGF-IR), the human insulin receptor (IR-A) and the human insulin

  3. The proto-oncogene product c-Crk associates with insulin receptor substrate-1 and 4PS. Modulation by insulin growth factor-I (IGF) and enhanced IGF-I signaling.

    Science.gov (United States)

    Beitner-Johnson, D; Blakesley, V A; Shen-Orr, Z; Jimenez, M; Stannard, B; Wang, L M; Pierce, J; LeRoith, D

    1996-04-19

    The Crk proto-oncogene product is an SH2 and SH3 domain-containing adaptor protein which we have previously shown to become rapidly tyrosine phosphorylated in response to stimulation with insulin-like growth factor I (IGF-I) in NIH-3T3 cells. In order to further characterize the role of Crk in the IGF-I signaling pathway, NIH-3T3 and 293 cells were stably transfected with an expression vector containing the Crk cDNA. The various resultant 3T3-Crk clones expressed Crk at approximately 2-15-fold higher levels than parental 3T3 cells. In 3T3-Crk cells, Crk immunoreactivity was detected in insulin receptor substrate-1 (IRS-1) immunoprecipitates. Stimulation with IGF-I resulted in a dissociation of Crk protein from IRS-1. In contrast, the association of the related adaptor protein Grb2 with IRS-1 was enhanced by IGF-I stimulation. Similar results were obtained in stably transfected 293-Crk cells, which express both IRS-1 and the IRS-1-related signaling protein 4PS. In these cells, IRS-1 and 4PS both associated with Crk, and this association was also decreased by IGF-I treatment, whereas the association of Grb2 with IRS-1 and 4PS was enhanced by IGF-I. Overexpression of Crk also enhanced IGF-I-induced mitogenesis of NIH-3T3 cells, as measured by [3H]thymidine incorporation. The levels of IGF-I-induced mitogenesis were proportional to the level of Crk expression. These results suggest that Crk is a positive effector of IGF-I signaling, and may mediate its effects via interaction with IRS-1 and/or 4PS.

  4. Clinical diagnostic value of combined determination of serum tPSA, cPSA and IGF-I levels in patients with prostatic disorders

    International Nuclear Information System (INIS)

    Zhang Bashan; Zhang Zigang; Lai Fudi

    2008-01-01

    Objective: To investigate the diagnostic value of combined determination of serum total prostatic specific antigen (tPSA), complex prostatic specific antigen (cPSA) and IGF-I levels in patients with prostatic disorders. Methods: Serum tPSA, cPSA (with CLIA) and IGF-I (with IRMA) levels were determined in 41 patients with prostatic carcinoma, 60 patients with benign prosta- tic hypertrophy (BPH) and 55 controls. Results: The serum tPSA, cPSA and IGF-I levels in patients with prostatic cancer were significantly higher than those in patients with BPH and controls (P<0.01). Taking the cut-off values of 4ng/ml, 3.6ng/ml and 150 for tPSA, cPSA and IGF-I respectively, the combined determination of these three items would yield a sensitivity of 88.6%, specificity of 84.9%, positive predicative value of 83% and negative predicative value of 90.0% for diagnosis of prostatic cancer. Conclusion: Combined determination of tPSA, cPSA and IGF-I would yield better sensitive and accurate diagnostic rate in patients with prostatic cancer, especially in those with laboratory values within the 'grey zone'. (authors)

  5. Impact of IGF-I release kinetics on bone healing: a preliminary study in sheep.

    Science.gov (United States)

    Luginbuehl, Vera; Zoidis, Evangelos; Meinel, Lorenz; von Rechenberg, Brigitte; Gander, Bruno; Merkle, Hans P

    2013-09-01

    Spatiotemporal release of growth factors from a delivery device can profoundly affect the efficacy of bone growth induction. Here, we report on a delivery platform based on the encapsulation of insulin-like growth factor I (IGF-I) in different poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) microsphere (MS) formulations to control IGF-I release kinetics. In vitro IGF-I release profiles generally exhibited an initial burst (14-36% of total IGF-I content), which was followed by a more or less pronounced dormant phase with little release (2 to 34 days), and finally, a third phase of re-increased IGF-I release. The osteoinductive potential of these different IGF-I PL(G)A MS formulations was tested in studies using 8-mm metaphyseal drill hole bone defects in sheep. Histomorphometric analysis at 3 and 6 weeks after surgery showed that new bone formation was improved in the defects locally treated with IGF-I PL(G)A MS (n=5) as compared to defects filled with IGF-I-free PL(G)A MS (n=4). The extent of new bone formation was affected by the particular release kinetics, although a definitive relationship was not evident. Local administration of IGF-I resulted in down-regulation of inflammatory marker genes in all IGF-I treated defects. The over-expression of growth factor genes in response to IGF-I delivery was restricted to formulations that produced osteogenic responses. These experiments demonstrate the osteoinductive potential of sustained IGF-I delivery and show the importance of delivery kinetics for successful IGF-I-based therapies. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. FOXO1 Content Is Reduced in Cystic Fibrosis and Increases with IGF-I Treatment

    Directory of Open Access Journals (Sweden)

    Arianna Smerieri

    2014-10-01

    Full Text Available Cystic fibrosis-related diabetes is to date the most frequent complication in cystic fibrosis (CF. The mechanisms underlying this condition are not well understood, and a possible role of insulin resistance is debated. We investigated insulin signal transduction in CF. Total insulin receptor, IRS1, p85 PI3K, and AKT contents were substantially normal in CF cells (CFBE41o-, whereas winged helix forkhead (FOXO1 contents were reduced both in baseline conditions and after insulin stimulation. In addition, CF cells showed increased ERK1/2, and reduced β2 arrestin contents. No significant change in SOCS2 was observed. By using a CFTR inhibitor and siRNA, changes in FOXO1 were related to CFTR loss of function. In a CF-affected mouse model, FOXO1 content was reduced in the muscle while no significant difference was observed in liver and adipose tissue compared with wild-type. Insulin-like growth factor 1 (IGF-I increased FOXO1 content in vitro and in vivo in muscle and adipose tissue. In conclusion; we present the first description of reduced FOXO1 content in CF, which is compatible with reduced gluconeogenesis and increased adipogenesis, both features of insulin insensitivity. IGF-I treatment was effective in increasing FOXO1, thereby suggesting that it could be considered as a potential treatment in CF patients possibly to prevent and treat cystic fibrosis-related diabetes.

  7. Insulin and IGF-II, but not IGF-I, stimulate the in vitro regeneration of adult frog sciatic sensory axons

    DEFF Research Database (Denmark)

    Edbladh, M; Svenningsen, Åsa Fex; Ekström, P A

    1994-01-01

    We used the in vitro regenerating frog sciatic nerve to look for effects of insulin and insulin-like growth factors I and II (IGF-I, IGF-II) on regeneration of sensory axons and on injury induced support cell proliferation in the outgrowth region. In nerves cultured for 11 days, a physiological...... dose (10 ng/ml, approximately 2 nM) of insulin or IGF-II increased ganglionic protein synthesis (by 20% and 50%, respectively) as well as the level of newly formed, radiolabelled axonal material distal to a crush injury (both by 80%), compared to untreated, paired controls. In addition, insulin...... increased the outgrowth distance of the furthest regenerating sensory axons by 10%. The preparation was particularly sensitive to insulin during the first 5 days of culturing. Furthermore, both insulin and IGF-II were found to inhibit proliferation of support cells in the outgrowth region in a manner...

  8. IGF-I levels reflect hypopituitarism severity in adults with pituitary dysfunction.

    Science.gov (United States)

    Tirosh, Amit; Toledano, Yoel; Masri-Iraqi, Hiba; Eizenberg, Yoav; Tzvetov, Gloria; Hirsch, Dania; Benbassat, Carlos; Robenshtok, Eyal; Shimon, Ilan

    2016-08-01

    To evaluate the utility of Insulin-like growth factor I (IGF-I) standard deviation score (SDS) as a surrogate marker of severity of hypopituitarism in adults with pituitary pathology. We performed a retrospective data analysis, including 269 consecutive patients with pituitary disease attending a tertiary endocrine clinic in 1990-2015. The medical files were reviewed for the complete pituitary hormone profile, including IGF-I, and clinical data. Age-adjusted assay reference ranges of IGF-I were used to calculate IGF-I SDS for each patient. The main outcome measures were positive and negative predictive values of low and high IGF-I SDS, respectively, for the various pituitary hormone deficiencies. IGF-I SDS correlated negatively with the number of altered pituitary axes (p hypopituitarism in adults with pituitary disease, and thus can serve as a marker of hypopituitarism severity.

  9. Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events.

    Directory of Open Access Journals (Sweden)

    Jyotsna U Rao

    Full Text Available The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF and apoptosis (BCL-2, FKHR, PAWR. These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

  10. Loss of neutrophil polarization in colon carcinoma liver metastases of mice with an inducible, liver-specific IGF-I deficiency.

    Science.gov (United States)

    Rayes, Roni F; Milette, Simon; Fernandez, Maria Celia; Ham, Boram; Wang, Ni; Bourdeau, France; Perrino, Stephanie; Yakar, Shoshana; Brodt, Pnina

    2018-03-20

    The growth of cancer metastases in the liver depends on a permissive interaction with the hepatic microenvironment and neutrophils can contribute to this interaction, either positively or negatively, depending on their phenotype. Here we investigated the role of IGF-I in the control of the tumor microenvironment in the liver, using mice with a conditional, liver-specific, IGF-I deficiency (iLID) induced by a single tamoxifen injection. In mice that had a sustained (3 weeks) IGF-I deficiency prior to the intrasplenic/portal inoculation of colon carcinoma MC-38 cells, we observed an increase in neutrophil accumulation in the liver relative to controls. However, unlike controls, these neutrophils did not acquire the (anti-inflammatory) tumor-promoting phenotype, as evidenced by retention of high ICAM-1 expression and nitric oxide production and low CXCR4, CCL5, and VEGF expression and arginase production, all characteristic of the (pro-inflammatory) phenotype. This coincided with an increase in apoptotic tumor cells and reduced metastasis. Neutrophils isolated from these mice also had reduced IGF-IR expression levels. These changes were not observed in iLID mice with a short-term (2 days) IGF-I depletion, despite a 70% reduction in their circulating IGF-I levels, indicating that a sustained IGF-I deficiency was necessary to alter the neutrophil phenotype. Similar results were obtained with the highly metastatic Lewis lung carcinoma subline H-59 cells and in mice injected with an IGF-Trap that blocks IGF-IR signaling by reducing ligand bioavailability. Our results implicate the IGF axis in neutrophil polarization and the induction of a pro-metastatic microenvironment in the liver.

  11. IGF-I and NEFA concentrations in fetal fluids of term pregnancy dogs.

    Science.gov (United States)

    Meloni, Tea; Comin, Antonella; Rota, Alessandro; Peric, Tanja; Contri, Alberto; Veronesi, Maria Cristina

    2014-06-01

    Insulin-like growth factor-I (IGF-I) and non-esterified fatty acids (NEFA) play an essential role in fetal growth and development. To date, fetal fluids IGF-I and NEFA levels at term canine pregnancy are unknown and could be related to the neonatal development and breed size. For these reasons, the aims of the present study were as follows: (1) to evaluate IGF-I and NEFA concentrations in fetal fluids collected from normally developed and viable newborn puppies born at term of normal pregnancies; (2) to assess possible differences between IGF-I and NEFA levels in amniotic compared with allantoic fluid; (3) to detect possible relationship between breed body size and IGF-I and NEFA amniotic and allantoic concentrations; (4) to evaluate possible differences in IGF-I fetal fluids levels between male and female puppies; and (5) to assess possible correlations between the two hormones in each type of fluid. The study enrolled 25 pure breed bitches submitted to elective Cesarean section at term because of the high risk of dystocia or previous troubles at parturition. At surgery, amniotic and allantoic fluids were collected and assayed for IGF-I and NEFA. IGF-I and NEFA amounts in both amniotic and allantoic fluids of different breed size bitches (small: ≤10 kg; medium: 11-25 kg; large: 26-40 kg) were detected, as well as the effect of gender on IGF-I levels. On a total of 73 amniotic and 76 allantoic samples collected by normal, viable, and mature newborns, the mean IGF-I concentration was significantly higher in amniotic than in allantoic fluid in all three groups, but the amniotic IGF-I levels were significantly lower in small and medium size bitches when compared with large ones. No significant differences were found in allantoic IGF-I concentrations among size groups. A significant effect of the puppy gender on IGF-I content in both fetal fluids was not reported. Regarding NEFA, in all the three groups, the mean NEFA concentration did not significantly differ

  12. Maternal BMI, IGF-I Levels, and Birth Weight in African American and White Infants

    Directory of Open Access Journals (Sweden)

    Adriana C. Vidal

    2013-01-01

    Full Text Available At birth, elevated IGF-I levels have been linked to birth weight extremes; high birth weight and low birth weight are risk factors for adult-onset chronic diseases including obesity, cardiovascular disease, and type 2 diabetes. We examined associations between plasma IGF-I levels and birth weight among infants born to African American and White obese and nonobese women. Prepregnancy weight and height were assessed among 251 pregnant women and anthropometric measurements of full term infants (≥37 weeks of gestation were taken at birth. Circulating IGF-I was measured by ELISA in umbilical cord blood plasma. Linear regression models were utilized to examine associations between birth weight and high IGF-I, using the bottom two tertiles as referents. Compared with infants with lower IGF-I levels (≤3rd tertile, those with higher IGF-I levels (>3rd tertile were 130 g heavier at birth, (β-coefficient=230, se=58.0, P=0.0001, after adjusting for gender, race/ethnicity, gestational age, delivery route, maternal BMI and smoking. Stratified analyses suggested that these associations are more pronounced in infants born to African American women and women with BMI ≥30 kg/m2; the cross product term for IGF-I and maternal BMI was statistically significant (P≤0.0004. Our findings suggest that the association between IGF-I levels and birth weight depends more on maternal obesity than African American race/ethnicity.

  13. Human conditions of insulin-like growth factor-I (IGF-I) deficiency

    Science.gov (United States)

    2012-01-01

    Insulin-like growth factor I (IGF-I) is a polypeptide hormone produced mainly by the liver in response to the endocrine GH stimulus, but it is also secreted by multiple tissues for autocrine/paracrine purposes. IGF-I is partly responsible for systemic GH activities although it possesses a wide number of own properties (anabolic, antioxidant, anti-inflammatory and cytoprotective actions). IGF-I is a closely regulated hormone. Consequently, its logical therapeutical applications seems to be limited to restore physiological circulating levels in order to recover the clinical consequences of IGF-I deficiency, conditions where, despite continuous discrepancies, IGF-I treatment has never been related to oncogenesis. Currently the best characterized conditions of IGF-I deficiency are Laron Syndrome, in children; liver cirrhosis, in adults; aging including age-related-cardiovascular and neurological diseases; and more recently, intrauterine growth restriction. The aim of this review is to summarize the increasing list of roles of IGF-I, both in physiological and pathological conditions, underlying that its potential therapeutical options seem to be limited to those proven states of local or systemic IGF-I deficiency as a replacement treatment, rather than increasing its level upper the normal range. PMID:23148873

  14. Differential binding of 125I-IGF-I preparations to human fibroblast monolayers

    International Nuclear Information System (INIS)

    Conover, C.A.; Misra, P.; Hintz, R.L.; Rosenfeld, R.G.

    1988-01-01

    Specific, high affinity binding of 125 I-IGF-I to the type IIGF receptor on human fibroblast monolyaers was not altered by varying feeding schedules, serum lots, washing procedures, or incubation times and temperatures. However, markedly different competitive binding curves were obtained when different iodinated IGF-I preparations were used. Five of six radioligands bound preferentially to the type IIGF receptor on human fibroblast monolayers, with 50% displacement at 4-8 μg/l unlabelled IGF-I; with one radioligand a paradoxical 20-200% increase in 125 I-IGF-I binding was observed at low concentrations of unlabelled IGF-I, while concentrations as high as 100 μg/l IGF-I failed to displace this radioligand. The latter binding pattern cannot be accounted for by 125 -I-IGF-I binding to the type II IGF receptor. These data indicate that various radioligands may have preferential affinities for different IGF-I binding sites on human fibroblast monolayers. (author)

  15. Human conditions of insulin-like growth factor-I (IGF-I deficiency

    Directory of Open Access Journals (Sweden)

    Puche Juan E

    2012-11-01

    Full Text Available Abstract Insulin-like growth factor I (IGF-I is a polypeptide hormone produced mainly by the liver in response to the endocrine GH stimulus, but it is also secreted by multiple tissues for autocrine/paracrine purposes. IGF-I is partly responsible for systemic GH activities although it possesses a wide number of own properties (anabolic, antioxidant, anti-inflammatory and cytoprotective actions. IGF-I is a closely regulated hormone. Consequently, its logical therapeutical applications seems to be limited to restore physiological circulating levels in order to recover the clinical consequences of IGF-I deficiency, conditions where, despite continuous discrepancies, IGF-I treatment has never been related to oncogenesis. Currently the best characterized conditions of IGF-I deficiency are Laron Syndrome, in children; liver cirrhosis, in adults; aging including age-related-cardiovascular and neurological diseases; and more recently, intrauterine growth restriction. The aim of this review is to summarize the increasing list of roles of IGF-I, both in physiological and pathological conditions, underlying that its potential therapeutical options seem to be limited to those proven states of local or systemic IGF-I deficiency as a replacement treatment, rather than increasing its level upper the normal range.

  16. Insulin-like growth factor (IGF-I and IGF binding proteins axis in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Min Sun Kim

    2015-06-01

    Full Text Available Increasing evidence suggests an important role of the insulin-like growth factor (IGF-IGF binding protein (IGFBP axis in the maintenance of normal glucose and lipid metabolism. Significant changes occur in the local IGF-I-IGFBPs environment in response to the diabetic milieu. A significant reduction of serum IGF-I levels was observed in patients with type 1 diabetes mellitus (T1DM. Inversely, considerably increased serum levels of IGF-I and IGFBP-3 levels were detected in individuals with glucose intolerance including T2DM. Recently, several prospective studies indicated that baseline levels of IGF-I and IGFBPs are associated with the development of diabetes. These findings suggest that disturbances in insulin and IGF-I-IGFBP axis can affect the development of glucose intolerance including diabetes.

  17. Divergent frequencies of IGF-I receptor-expressing blood lymphocytes in monozygotic twin pairs discordant for Graves' disease: evidence for a phenotypic signature ascribable to nongenetic factors

    DEFF Research Database (Denmark)

    Douglas, Raymond S; Brix, Thomas H; Hwang, Catherine J

    2009-01-01

    CONTEXT: Graves' disease (GD) is an autoimmune process of the thyroid and orbital connective tissues. The fraction of T and B cells expressing IGF-I receptor (IGF-IR) is increased in GD. It is a potentially important autoantigen in GD. Susceptibility to GD arises from both genetic and acquired...

  18. Insulin and IGF-II, but not IGF-I, stimulate the in vitro regeneration of adult frog sciatic sensory axons

    DEFF Research Database (Denmark)

    Edbladh, M; Svenningsen, Åsa Fex; Ekström, P A

    1994-01-01

    We used the in vitro regenerating frog sciatic nerve to look for effects of insulin and insulin-like growth factors I and II (IGF-I, IGF-II) on regeneration of sensory axons and on injury induced support cell proliferation in the outgrowth region. In nerves cultured for 11 days, a physiological...

  19. Effect of Modified and accumulated decoction on serum ER, PR, sex hormone, IGF-I and IGF-I in patients with uterine fibroids

    Directory of Open Access Journals (Sweden)

    Yi-Sha Li

    2017-11-01

    Full Text Available Objective: To study the effect of Modified and accumulated Decoction on serum ER, PR, sex hormone, IGF-I and IGF-I in patients with uterine fibroids. Method: A total of 90 patients with uterine fibroids in our hospital from January 2015 to January 2017 were enrolled in this study. The subjects were divided into the control group (n=45 and the treatment group (n=45 randomly. The control group was treated with mifepristone, the treatment group was treated with Modified and accumulated Decoction combined with mifepristone, and both the two groups were treated for 3 months. The uterine fibroid volume and uterine volume of the two groups before and after treatment were compared. The serum ER, PR, P, E 2 , LH, FSH, IGF-I and IGF-IR of the two groups before and after treatment were compared. Result: There were no significantly differences of the uterine fibroid volume and uterine volume of the two groups before treatment. The uterine fibroid volume and uterine volume of the two groups after treatment were significantly less than before treatment, and that of the treatment group after treatment were significantly less than the control group. There were no significantly differences among the serum ER, PR, P, E 2 , LH, FSH, IGF-I and IGF-IR of the two groups before treatment. The serum ER, PR, P, E 2 , LH, FSH, IGF-I and IGF-IR of the two groups after treatment were significantly lower than before treatment, and that of the treatment group after treatment were significantly lower than the control group. Conclusion: Modified and accumulated Decoction combined with mifepristonecan significantly reduce the uterine fibroid volume, improve the serum ER, PR, sex hormone, IGF-I and IGF-I levels of the patients with uterine fibroids, and it was worthy clinical application.

  20. Positive associations between serum levels of IGF-I and subcutaneous fat depots in young men. The Odense Androgen Study

    DEFF Research Database (Denmark)

    Andersen, M; Brixen, K; Hagen, C

    2012-01-01

    Serum levels of IGF-I are of growing interest due to the associations with morbidity and mortality. Despite markedly suppressed GH secretion, total IGF-I levels are often within normal range in obese adults.......Serum levels of IGF-I are of growing interest due to the associations with morbidity and mortality. Despite markedly suppressed GH secretion, total IGF-I levels are often within normal range in obese adults....

  1. Postprandial hyperglycemia corrected by IGF-I (Increlex®) in Laron syndrome.

    Science.gov (United States)

    Latrech, Hanane; Simon, Albane; Beltrand, Jacques; Souberbielle, Jean-Claude; Belmejdoub, Ghizlane; Polak, Michel

    2012-01-01

    Laron syndrome is caused by a mutation in the growth hormone (GH) receptor and manifests as insulin-like growth factor-I (IGF-I) deficiency, severe short stature, and early hypoglycemia. We report a case with postprandial hyperglycemia, an abnormality not reported previously. Postprandial hyperglycemia was due to chronic IGF-I deficiency, and was reversed by IGF-I replacement therapy. A Moroccan girl referred for short stature at 7 years and 8 months of age had dwarfism [height, 78 cm (-9 SDs); weight, 10 kg (-4 SDs)], hypoglycemia, and truncal obesity. Her serum IGF-I level was very low, and her baseline serum GH level was elevated to 47 mIU/l. Molecular analysis showed a homozygous mutation in the GH receptor gene. Continuous glucose monitoring before treatment showed asymptomatic hypoglycemia with postprandial hyperglycemia (2.5 g/l, 13.75 mmol/l). Treatment with recombinant human IGF-I (mecasermin, Increlex®) was started. The blood glucose profile improved with 0.04 µg/kg/day and returned to normal with 0.12 µg/kg/day. Postprandial hyperglycemia is a metabolic consequence of chronic IGF-I deficiency. The beneficial effect of IGF-I replacement therapy may be ascribable to improved postprandial transfer of glucose. Copyright © 2012 S. Karger AG, Basel.

  2. A polymorphism in the gene for IGF-I: functional properties and risk for type 2 diabetes and myocardial infarction

    NARCIS (Netherlands)

    N. Vaessen (Norbert); J.C.M. Witteman (Jacqueline); L. Testers; S.W.J. Lamberts (Steven); B.A. Oostra (Ben); H.A.P. Pols (Huib); C.M. van Duijn (Cornelia); J.A.M.J.L. Janssen (Joseph); P. Heutink (Peter); A. Hofman (Albert)

    2001-01-01

    textabstractEvidence is accumulating that low levels of IGF-I play a role in the pathogenesis of type 2 diabetes and cardiovascular diseases. We examined the role of a genetic polymorphism in the promoter region of the IGF-I gene in relation to circulating IGF-I levels and growth measured as body

  3. Targeting either GH or IGF-I during somatostatin analogue treatment in patients with acromegaly

    DEFF Research Database (Denmark)

    Dal, Jakob; Klose, Marianne; Heck, Ansgar

    2018-01-01

    CONTEXT: Discordant GH and IGF-I values are frequent in acromegaly. The clinical significance and its dependence on treatment modality and of glucose-suppressed GH (GHnadir) measurements remain uncertain. OBJECTIVE: To evaluate the effects of targeting either IGF-I or GH during somatostatin analog...... (SA) treatment. PATIENTS AND METHODS: 84 patients with controlled acromegaly after surgery (n=23) or SA (n=61) underwent a GH-profile including an OGTT, at baseline and after 12 months. SA patients were randomized to monitoring according to either IGF-I (n= 33) or GHnadir (n=28). SA dose escalation...

  4. Overexpression of IGF-I in skeletal muscle of transgenic mice does not prevent unloading-induced atrophy

    Science.gov (United States)

    Criswell, D. S.; Booth, F. W.; DeMayo, F.; Schwartz, R. J.; Gordon, S. E.; Fiorotto, M. L.

    1998-01-01

    This study examined the association between local insulin-like growth factor I (IGF-I) overexpression and atrophy in skeletal muscle. We hypothesized that endogenous skeletal muscle IGF-I mRNA expression would decrease with hindlimb unloading (HU) in mice, and that transgenic mice overexpressing human IGF-I (hIGF-I) specifically in skeletal muscle would exhibit less atrophy after HU. Male transgenic mice and nontransgenic mice from the parent strain (FVB) were divided into four groups (n = 10/group): 1) transgenic, weight-bearing (IGF-I/WB); 2) transgenic, hindlimb unloaded (IGF-I/HU); 3) nontransgenic, weight-bearing (FVB/WB); and 4) nontransgenic, hindlimb unloaded (FVB/HU). HU groups were hindlimb unloaded for 14 days. Body mass was reduced (P < 0.05) after HU in both IGF-I (-9%) and FVB mice (-13%). Contrary to our hypothesis, we found that the relative abundance of mRNA for the endogenous rodent IGF-I (rIGF-I) was unaltered by HU in the gastrocnemius (GAST) muscle of wild-type FVB mice. High-level expression of hIGF-I peptide and mRNA was confirmed in the GAST and tibialis anterior (TA) muscles of the transgenic mice. Nevertheless, masses of the GAST and TA muscles were reduced (P < 0.05) in both FVB/HU and IGF-I/HU groups compared with FVB/WB and IGF-I/WB groups, respectively, and the percent atrophy in mass of these muscles did not differ between FVB and IGF-I mice. Therefore, skeletal muscle atrophy may not be associated with a reduction of endogenous rIGF-I mRNA level in 14-day HU mice. We conclude that high local expression of hIGF-I mRNA and peptide in skeletal muscle alone cannot attenuate unloading-induced atrophy of fast-twitch muscle in mice.

  5. Insulin-like growth factor binding protein-3 induces angiogenesis through IGF-I- and SphK1-dependent mechanisms.

    Science.gov (United States)

    Granata, R; Trovato, L; Lupia, E; Sala, G; Settanni, F; Camussi, G; Ghidoni, R; Ghigo, E

    2007-04-01

    Angiogenesis is critical for development and repair, and is a prominent feature of many pathological conditions. Based on evidence that insulin-like growth factor binding protein (IGFBP)-3 enhances cell motility and activates sphingosine kinase (SphK) in human endothelial cells, we have investigated whether IGFBP-3 plays a role in promoting angiogenesis. IGFBP-3 potently induced network formation by human endothelial cells on Matrigel. Moreover, it up-regulated proangiogenic genes, such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP)-2 and -9. IGFBP-3 even induced membrane-type 1 MMP (MT1-MMP), which regulates MMP-2 activation. Decreasing SphK1 expression by small interfering RNA (siRNA), blocked IGFBP-3-induced network formation and inhibited VEGF, MT1-MMP but not IGF-I up-regulation. IGF-I activated SphK, leading to sphingosine-1-phosphate (S1P) formation. The IGF-I effect on SphK activity was blocked by specific inhibitors of IGF-IR, PI3K/Akt and ERK1/2 phosphorylation. The disruption of IGF-I signaling prevented the IGFBP-3 effect on tube formation, SphK activity and VEGF release. Blocking ERK1/2 signaling caused the loss of SphK activation and VEGF and IGF-I up-regulation. Finally, IGFBP-3 dose-dependently stimulated neovessel formation into subcutaneous implants of Matrigel in vivo. Thus, IGFBP-3 positively regulates angiogenesis through involvement of IGF-IR signaling and subsequent SphK/S1P activation.

  6. Muscle atrophy in patients wirh ckd results from fgf23/klotho-mediated supression of insulin/igf-i signaling

    Directory of Open Access Journals (Sweden)

    Shinsuke Kido

    2012-06-01

    Full Text Available Muscle atrophy is a significant consequence of chronic kidney disease (CKD that increases a patient’s risk of mortality and decrease their quality of life. In CKD patients, the circulation levels of FGF23 are significantly increased, but the exact pathological significance of the increase and relationship between FGF23 and muscle atrophy are not clear. Because of Klohto, acts as a co-receptor of FGF23 is detectable in limited tissues including in kidney and brain, but not in skeletal muscles. In contrast, recently reports indicated that the extracellular domain of klohto is cleavage for some reason on the cell surface and detected in the blood in animals. In this study, we attempted to identify the causative factors responsible for the shedding of Klotho, and whether both FGF23 and Klohto induced muscle atrophy via reduction of insulin/IGF-I signaling. We first investigated by treating kidney cells with various factors related in pathological factors in CKD. As a result, we found that advanced glycation endproducts (AGEs, an accumulated in patients with CKD and diabetes mellitus, increases shedding of Klohto in kidney cells. It is common knowledge that insulin/IGF-I signaling is necessary for normal skeletal growth. As a result, we showed that both FGF23 and Klohto inhibited differentiation of cultured skeletal muscle cells through down-regulation of insulin/IGF-I signaling. These observations suggested a divergent role of FGF23 and soluble klohto in the regulation of skeletal muscle differentiation and thereby muscle atrophy under pathological conditioned in CKD patients. Our results further imply that FGF23/Klohto may serve a new therapeutic target for CKD-induced muscle atrophy.

  7. Clinical significance of determination of serum IGF-I and SIL-2R levels in patients with prostatic cancer

    International Nuclear Information System (INIS)

    Zhang Zaigao; Lv Yuliang; Li Jiacheng

    2006-01-01

    Objective: To investigate the significance of changes of serum IGF-I and SIL-2R levels in patients with prostatic cancer. Methods: Serum IGF-I levels (with RIA) and SIL-2R levels (with ELISA) were measured in 31 patients with prostatic cancer and 30 controls. Results: Serum levels of IGF-I and SIL-2R in the 31 patients were significantly higher than those in controls (P<0.01), serum IGF-I and SIL-2R levels were mutually positively correlated (r=0.6182, P<0.01). Conclusion: Serum IGF-I and SIL-2R were useful markers for prostatic cancer. (authors)

  8. Study on the correlationship between serum IGF-I and HA, PIIIP levels in patients with chronic hepatitis C

    International Nuclear Information System (INIS)

    Li Yong; Sun Yefu; Xia Aiping

    2008-01-01

    Objective: To study the inter-relationship between serum IGF-I and HA, PIIIP levels in patients with chronic hepatitis C. Methods: Serum IGF-I, HA and PIIIP levels were determined with RIA in 39 patients with chronic hepatitis C and 35 controls. Results: Serum IGF-I, HA and PIIIP levels in the patients were significantly higher than those in controls (P<0.01). The serum IGF-I levels and HA, PIIIP levels were mutually positively correlated (r=0.8018, 0.7126, P<0.01). Conclusion: Serum IGF-I, HA and PIIIP were useful diagnostic markers in patients with chronic hepatitis C. (authors)

  9. Polymorphism in NPY and IGF-I genes associate with reproductive ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... effects of NPY and IGF-I genes on reproductive traits of chickens. Key words: ... flavor and good egg quality are accorded with Chinese consumers' taste. ... Numerous studies in mammals and more recently in teleost fish.

  10. Long-term IGF-I treatment of children with Laron syndrome increases adiposity.

    Science.gov (United States)

    Laron, Zvi; Ginsberg, Shira; Lilos, Pnina; Arbiv, Mira; Vaisman, Nahum

    2006-02-01

    Laron syndrome (LS) is an autosomal recessive disease caused by deletions or mutations in the GH receptor gene leading to an inability of insulin-like growth factor I (IGF-I) generation. Among the major resulting body changes are dwarfism and obesity. The only effective treatment is daily administration of biosynthetic IGF-I. Body composition determination by DEXA (dual energy X-ray absorptiometry) of three girls with LS treated by IGF-I for 1, 3 and 11 1/2 years, respectively, revealed that concomitantly with the increase in growth there was a significant increase in body adipose tissue to double or triple the normal values. Due to the underdevelopment of the muscular and skeletal systems body mass index (BMI) did not accurately reflect the degree of obesity. In conclusion, IGF-I similar to insulin, exerts an adipogenic effect.

  11. IGF-I Gene Therapy in Aging Rats Modulates Hippocampal Genes Relevant to Memory Function.

    Science.gov (United States)

    Pardo, Joaquín; Abba, Martin C; Lacunza, Ezequiel; Ogundele, Olalekan M; Paiva, Isabel; Morel, Gustavo R; Outeiro, Tiago F; Goya, Rodolfo G

    2018-03-14

    In rats, learning and memory performance decline during normal aging, which makes this rodent species a suitable model to evaluate therapeutic strategies. In aging rats, insulin-like growth factor-I (IGF-I), is known to significantly improve spatial memory accuracy as compared to control counterparts. A constellation of gene expression changes underlie the hippocampal phenotype of aging but no studies on the effects of IGF-I on the hippocampal transcriptome of old rodents have been documented. Here, we assessed the effects of IGF-I gene therapy on spatial memory performance in old female rats and compared them with changes in the hippocampal transcriptome. In the Barnes maze test, experimental rats showed a significantly higher exploratory frequency of the goal hole than controls. Hippocampal RNA-sequencing showed that 219 genes are differentially expressed in 28-month-old rats intracerebroventricularly injected with an adenovector expressing rat IGF-I as compared with placebo adenovector-injected counterparts. From the differentially expressed genes, 81 were down and 138 upregulated. From those genes, a list of functionally relevant genes, concerning hippocampal IGF-I expression, synaptic plasticity as well as neuronal function was identified. Our results provide an initial glimpse at the molecular mechanisms underlying the neuroprotective actions of IGF-I in the aging brain.

  12. Relationship between cord blood IGF-I, IGFBP-3 levels and intrauterine growth retardation (IUGR)

    International Nuclear Information System (INIS)

    Yu Suqing; Chu Kaiqiu; Chen Shengjie

    2008-01-01

    Objective: To study the cord blood insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3) levels in neonates with intrauterine growth retardation (IUGR). Methods: Cord serum IGF-I (with RIA) and IGFBP-3 (with IRMA) levels were measured in 22 neonates with IUGR and 64 neonates with appropriate gestational age (AGA). Results: Cord blood IGF-I and IGFBP-3 levels in IUGR neonates were significantly lower than those in AGA neonates (P<0.001). Among the 86 neonates studied in this article, 44 were born pre-term and 42 were born full term. From the data, we could see that the cord blood IGF-I and IGFBP-3 levels in pre-term neonates were significantly lower than those in full-term neonates (P also <0.001). IGF-I and IGFBP-3 levels were mutually positively correlated (P<0.01). Conclusion: Cord blood IGF-I and IGFBP-3 levels were useful indicator of neonates growth. (authors)

  13. Genetic Mutations, Birth Lengths, Weights and Head Circumferences of Children with IGF-I Receptor Defects. Comparison with other Congenital Defects in the GH/IGF-I axis.

    Science.gov (United States)

    Essakow, Jenna Lee; Lauterpacht, Aharon; Lilos, Pearl; Kauli, Rivka; Laron, Zvi

    2016-09-01

    In recent years more and more genetic defects along the GHRH-GH-IGF-I axis have been reported. Mutations of the IGF-I receptor (R) are a rare abnormality of whom only the heterozygote progenies survive. To summarize, from the literature, data on birth length, weight and head circumference of neonates with IGF-I-R mutations, and to correlate the data with that of other types of mutations in the GH/IGF-I axis. Sixty seven neonates from 24 published articles were included and forty seven different mutations of the IGF-I (R) located on chromosome 15 have been identified. Mean (±SD) birth length (BL), available for 26, (10 M, 16F) neonates with a gestational age of 34-41weeks, was 44.2±4cm; one was premature (30cm at 31 weeks). There was a significant correlation between birth length and gestational age (GA) r=0.71 (p>.001). Mean birth weight (BW) of 41 neonates (18M, 23F) was 2388±743gr. Two premature neonates weighed 650gr and 950gr respectively. The BW correlated significantly with gestational age, (males: r=0.68; p=0.007, females: r=0.49; p=0.024). The BMI of 25 neonates ranged from 6 to 13. In 22 records marked microcephaly was ascertained or stated. Nine of 16 mothers were short (133 -148cm), m±SD = 150.5±7.3cm. Copyright© of YS Medical Media ltd.

  14. Effects of dietary genistein on GH/IGF-I axis of Nile tilapia Oreochromis niloticus

    Science.gov (United States)

    Chen, Dong; Wang, Wei; Ru, Shaoguo

    2016-09-01

    There is considerable concern that isoflavones, such as genistein in fish feed composed of soybean protein, aff ects somatic growth in fish. Our previous works demonstrated that 30 and 300 μg/g dietary genistein had no significant eff ect on growth performance in Nile tilapia ( Oreochromis niloticus), but the higher level of genistein (3 000 μg/g) significantly depressed growth. This study was conducted to further examine the eff ects of dietary genistein on the endocrine disruption on growth hormone/insulin-like growth factor-I (GH/IGF-I) axis in Nile tilapia ( O. niloticus). Juvenile fish were fed by hand twice daily to satiation with one of four isonitrogenous and isoenergetic diets, each containing either 0, 30, 300 or 3 000 μg/g genistein. Following an 8-week feeding period, plasma GH and IGF-I levels were investigated by radioimmunoassay and gene expression levels of gh, ghrelin, gnrhs, ghr, npy, npyrs, pacap, ghrs, i gf-I, igf-Ir, and igfbp3 were examined by real-time PCR. The results show that no significant change in plasma GH and IGF-I levels in fish fed with diets containing 30 μg/g and 300 μg/g genistein. mRNA expression of genes along the GH/IGF-I axis remained unaff ected, except for igf-Ir, which was stimulated by the 300 μg/g genistein diet. While in fish fed the 3 000 μg/g genistein diet, the plasma GH and IGF-I levels decreased, and mRNA expression of gh, ghr2, npyr1, igf-I, and igf-Ir were also significantly depressed. In contrast, npy and igfbp3 mRNA expression were enhanced. This study provides convincing evidence for growth impediment by genistein by disturbing the GH/IGF-I axis in Nile tilapia O. niloticus.

  15. Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays; Improvement of determinations in acid ethanol extracts by the use of truncated IGF-I as radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Bang, P; Eriksson, U; Wivall, I -L; Hall, K [Department of Endocrinology, Karolinska Institute, Stockholm (Sweden); Sara, V [Department of Pathology, Karolinska Institute, Stockholm (Sweden)

    1991-01-01

    Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N=42, r=0.91, p<0.001) and in patients with acromegaly (N=10, r=0.85, p<0.01), GH deficiency (N=10, r=0.88, p<0.001) or Type I diabetes mellitus (N=10, r=0.90, p<0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r=0.61, NS) or GH deficiency (r=0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand. (author).

  16. Favorable prognostic value of SOCS2 and IGF-I in breast cancer

    International Nuclear Information System (INIS)

    Haffner, Michael C; Petridou, Barbara; Peyrat, Jean Phillipe; Révillion, Françoise; Müller-Holzner, Elisabeth; Daxenbichler, Günter; Marth, Christian; Doppler, Wolfgang

    2007-01-01

    Suppressor of cytokine signaling (SOCS) proteins comprise a protein family, which has initially been described as STAT induced inhibitors of the Jak/Stat pathway. Recent in vivo and in vitro studies suggest that SOCS proteins are also implicated in cancer. The STAT5 induced IGF-I acts as an endocrine and para/autocrine growth and differentiation factor in mammary gland development. Whereas high levels of circulating IGF-I have been associated with increased cancer risk, the role of autocrine acting IGF-I is less clear. The present study is aimed to elucidate the clinicopathological features associated with SOCS1, SOCS2, SOCS3, CIS and IGF-I expression in breast cancer. We determined the mRNA expression levels of SOCS1, SOCS2, SOCS3, CIS and IGF-I in 89 primary breast cancers by reverse transcriptase PCR. SOCS2 protein expression was further evaluated by immuno-blot and immunohistochemistry. SOCS2 expression inversely correlated with histopathological grade and ER positive tumors exhibited higher SOCS2 levels. Patients with high SOCS2 expression lived significantly longer (108.7 vs. 77.7 months; P = 0.015) and high SOCS2 expression proved to be an independent predictor for good prognosis (HR = 0.45, 95% CI 0.23 – 0.91, P = 0.026). In analogy to SOCS2, high IGF-I expression was an independent predictor for good prognosis in the entire patient cohort. In the subgroup of patients with lymph-node negative disease, high IGF-I was a strong predictor for favorable outcome in terms of overall survival and relapse free survival (HR = 0.075, 95% CI 0.014 – 0.388, P = 0.002). This is the first report on the favorable prognostic value of high SOCS2 expression in primary mammary carcinomas. Furthermore a strong association of high IGF-I expression levels with good prognosis was observed especially in lymph-node negative patients. Our results suggest that high expression of the STAT5 target genes SOCS2 and IGF-I is a feature of differentiated and less malignant tumors

  17. Favorable prognostic value of SOCS2 and IGF-I in breast cancer

    Directory of Open Access Journals (Sweden)

    Daxenbichler Günter

    2007-07-01

    Full Text Available Abstract Background Suppressor of cytokine signaling (SOCS proteins comprise a protein family, which has initially been described as STAT induced inhibitors of the Jak/Stat pathway. Recent in vivo and in vitro studies suggest that SOCS proteins are also implicated in cancer. The STAT5 induced IGF-I acts as an endocrine and para/autocrine growth and differentiation factor in mammary gland development. Whereas high levels of circulating IGF-I have been associated with increased cancer risk, the role of autocrine acting IGF-I is less clear. The present study is aimed to elucidate the clinicopathological features associated with SOCS1, SOCS2, SOCS3, CIS and IGF-I expression in breast cancer. Methods We determined the mRNA expression levels of SOCS1, SOCS2, SOCS3, CIS and IGF-I in 89 primary breast cancers by reverse transcriptase PCR. SOCS2 protein expression was further evaluated by immuno-blot and immunohistochemistry. Results SOCS2 expression inversely correlated with histopathological grade and ER positive tumors exhibited higher SOCS2 levels. Patients with high SOCS2 expression lived significantly longer (108.7 vs. 77.7 months; P = 0.015 and high SOCS2 expression proved to be an independent predictor for good prognosis (HR = 0.45, 95% CI 0.23 – 0.91, P = 0.026. In analogy to SOCS2, high IGF-I expression was an independent predictor for good prognosis in the entire patient cohort. In the subgroup of patients with lymph-node negative disease, high IGF-I was a strong predictor for favorable outcome in terms of overall survival and relapse free survival (HR = 0.075, 95% CI 0.014 – 0.388, P = 0.002. Conclusion This is the first report on the favorable prognostic value of high SOCS2 expression in primary mammary carcinomas. Furthermore a strong association of high IGF-I expression levels with good prognosis was observed especially in lymph-node negative patients. Our results suggest that high expression of the STAT5 target genes SOCS2 and IGF-I

  18. Diabetic retinopathy in two patients with congenital IGF-I deficiency (Laron syndrome).

    Science.gov (United States)

    Laron, Zvi; Weinberger, Dov

    2004-07-01

    Animal and clinical studies have shown that excessive amounts of growth hormone or insulin-like growth factor-I (IGF-I) promote the development of diabetes and diabetic retinopathy. Forthwith, we present two patients with congenital IGF-I deficiency who developed type II diabetes and subsequently retinopathy. Eighteen adult patients with classical Laron syndrome (8 males, 10 females, aged 20-62 years) were followed by us since childhood or underwent fundus photography with a Nikon NF 505 instrument. Three had been treated in childhood with IGF-I, the rest were never treated, including the two patients reported. Two never-treated patients were diagnosed with type II diabetes (DM) at ages 39 and 41 respectively. There was no diabetes in the families. Oral treatment was followed by insulin injections. Metabolic control was not optimal and one patient developed proliferative diabetic retinopathy, necessitating laser surgery. He also has nephropathy and severe neuropathy. The other patient has background diabetic retinopathy and has developed, progressively, exudates, microaneurisms, hemorrhages and clinically significant macular edema. He also has subacute ischemic heart disease. Our findings show that congenital IGF-I deficiency, similar to excess, causes vascular complications of DM, denoting also that vascular endothelial growth factor can induce neovascularization in the presence of congenital IGF-I deficiency.

  19. Clinical significance of changes of serum expression of IGF-I in patients with astrocytoma

    International Nuclear Information System (INIS)

    Liu Jianbo; Ding Dongmei; Yang Fubing

    2005-01-01

    Objective: To investigate the serum expression of IGF-I in patients with astrocytoma of different degrees of malignancy as well as the changes of levels after operative removal of the tumor. Methods: Serum IGF-I contents were measured with IRMA in 16 patients with Grade I-II astrocytoma and 14 patients with Grade III-IV astrocytoma both before and after operation as well as in 30 controls. Results: The serum contents of IGF-I in both groups of patients were significantly higher than those in controls (P<0.05). The levels in Grade III-IV patients were significantly higher than those in Grade I-II patients (P < 0.05 ). After operation, the levels dropped significantly (vs before operation, P<0.05). Conclusion: The serum contents of IGF - I in patients with astrocytoma were positively correlated with the degree of malignancy. Post-operative decrease of IGF-I contents was related to the decrease of tumor burden. (authors)

  20. Serum insulin-like growth factor-I (IGF-I) levels during long-term IGF-I treatment of children and adults with primary GH resistance (Laron syndrome).

    Science.gov (United States)

    Laron, Z; Klinger, B; Silbergeld, A

    1999-01-01

    Serum IGF-I levels were measured in 14 patients (9 children and 5 adults) with Laron syndrome (LS) during long-term treatment by IGF-I. Recombinant IGF-I (FK-780, Fujisawa Pharmaceutical Co. Ltd., Japan) was administered once daily subcutaneously before breakfast for 3-5 years to the children and for 9 months to the adults. The initial daily dose was 150 micrograms/kg for children and 120 micrograms/kg for adults. Before initiation of treatment the mean overnight fasting levels of serum IGF-I in the children was 3.2 +/- 0.8 nmol/l (mean +/- SEM), rising to 10 +/- 1.7 nmol/l during long-term treatment even on a dose of 120 micrograms/kg/day. The serum IGF-I levels 4 hours after injection rose from 31.2 +/- 3.5 to 48 +/- 2 nmol/l. In the adult patients, the initial basal IGF-I was 4.1 +/- 0.7 nmol/l, rising to 16.1 +/- 3.84 nmol/l after 8-9 months treatment. Serum IGF-I levels at 4 hours after injection rose in the adult patients from 24.1 +/- 5.8 up to 66.8 +/- 15.4 nmol/l. A progressively increasing half-life during long term exogenous administration of IGF-I to patients with Laron syndrome was demonstrated by following serum IGF-I dynamics after injection. Based on the fact that no antibodies to IGF-I were detected and on findings in previous studies, it is speculated that the increasing serum IGF-I levels during long-term IGF-I treatment are caused by an increase in serum IGFBP-3 induced by chronic IGF-I administration. It is concluded that treatment with IGF-I necessitates regular monitoring of serum IGF-I levels; in patients in whom the age adjusted maximal levels are exceeded, a reduction of the daily IGF-I dose is indicated to avoid undesirable effects.

  1. Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays

    International Nuclear Information System (INIS)

    Bang, P.; Eriksson, U.; Wivall, I.-L.; Hall, K.; Sara, V.

    1991-01-01

    Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N=42, r=0.91, p<0.001) and in patients with acromegaly (N=10, r=0.85, p<0.01), GH deficiency (N=10, r=0.88, p<0.001) or Type I diabetes mellitus (N=10, r=0.90, p<0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r=0.61, NS) or GH deficiency (r=0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand. (author)

  2. Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy

    2003-01-01

    The proposal entitled "Effects of moderate aerobic exercise combined with caloric restriction on circulating estrogens and IGF-I in premenopausal women will provide important scientific contributions...

  3. Detection of exogenous gene doping of IGF-I by a real-time quantitative PCR assay.

    Science.gov (United States)

    Zhang, Jin-Ju; Xu, Jing-Feng; Shen, Yong-Wei; Ma, Shi-Jiao; Zhang, Ting-Ting; Meng, Qing-Lin; Lan, Wen-Jun; Zhang, Chun; Liu, Xiao-Mei

    2017-07-01

    Gene doping can be easily concealed since its product is similar to endogenous protein, making its effective detection very challenging. In this study, we selected insulin-like growth factor I (IGF-I) exogenous gene for gene doping detection. First, the synthetic IGF-I gene was subcloned to recombinant adeno-associated virus (rAAV) plasmid to produce recombinant rAAV2/IGF-I-GFP vectors. Second, in an animal model, rAAV2/IGF-I-GFP vectors were injected into the thigh muscle tissue of mice, and then muscle and blood specimens were sampled at different time points for total DNA isolation. Finally, real-time quantitative PCR was employed to detect the exogenous gene doping of IGF-I. In view of the characteristics of endogenous IGF-I gene sequences, a TaqMan probe was designed at the junction of exons 2 and 3 of IGF-I gene to distinguish it from the exogenous IGF-I gene. In addition, an internal reference control plasmid and its probe were used in PCR to rule out false-positive results through comparison of their threshold cycle (Ct) values. Thus, an accurate exogenous IGF-I gene detection approach was developed in this study. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  4. Relación entre los niveles circulantes del factor de crecimiento similar a la insulina tipo I (IGF-I) y la expresión diferencial de genes relacionados con migración en células linfoides / Relatioship between circulating levels of insulin-like growth factor-I and differential expression of genes related to lymphoid cell migration

    OpenAIRE

    Cuervo Escobar, Sergio Andrei

    2011-01-01

    A partir de investigaciones realizadas en los últimos años, se ha hecho evidente la comunicación bidireccional entre los sistemas inmune y endocrino. Existe un gran cuerpo de evidencia que sugiere que el eje conformado por la hormona de crecimiento (GH) y el factor de crecimiento similar a la insulina tipo I (IGF-I) tiene un papel importante en la funcionalidad del sistema inmune. Los efectos de estas hormonas sobre los diferentes tipos celulares y tejidos pueden darse por meca...

  5. A moderate elevation of circulating levels of IGF-I does not alter ErbB2 induced mammary tumorigenesis

    International Nuclear Information System (INIS)

    Dearth, Robert K; Kuiatse, Isere; Wang, Yu-Fen; Liao, Lan; Hilsenbeck, Susan G; Brown, Powel H; Xu, Jianming; Lee, Adrian V

    2011-01-01

    Epidemiological evidence suggests that moderately elevated levels of circulating insulin-like growth factor-I (IGF-I) are associated with increased risk of breast cancer in women. How circulating IGF-I may promote breast cancer incidence is unknown, however, increased IGF-I signaling is linked to trastuzumab resistance in ErbB2 positive breast cancer. Few models have directly examined the effect of moderately high levels of circulating IGF-I on breast cancer initiation and progression. The purpose of this study was to assess the ability of circulating IGF-I to independently initiate mammary tumorigenesis and/or accelerate the progression of ErbB2 mediated mammary tumor growth. We crossed heterozygous TTR-IGF-I mice with heterozygous MMTV-ErbB2 mice to generate 4 different genotypes: TTR-IGF-I/MMTV-ErbB2 (bigenic), TTR-IGF-I only, MMTV-ErbB2 only, and wild type (wt). Virgin females were palpated twice a week and harvested when tumors reached 1000 mm 3 . For study of normal development, blood and tissue were harvested at 4, 6 and 9 weeks of age in TTR-IGF-I and wt mice. TTR-IGF-I and TTR-IGF-I/ErbB2 bigenic mice showed a moderate 35% increase in circulating total IGF-I compared to ErbB2 and wt control mice. Elevation of circulating IGF-I had no effect upon pubertal mammary gland development. The transgenic increase in IGF-I alone wasn't sufficient to initiate mammary tumorigenesis. Elevated circulating IGF-I had no effect upon ErbB2-induced mammary tumorigenesis or metastasis, with median time to tumor formation being 30 wks and 33 wks in TTR-IGF-I/ErbB2 bigenic and ErbB2 mice respectively (p = 0.65). Levels of IGF-I in lysates from ErbB2/TTR-IGF-I tumors compared to ErbB2 was elevated in a similar manner to the circulating IGF-I, however, there was no effect on the rate of tumor growth (p = 0.23). There were no morphological differences in tumor type (solid adenocarcinomas) between bigenic and ErbB2 mammary glands. Using the first transgenic animal model to

  6. IGF-I and IGFBP-3 polymorphisms in relation to circulating levels among African American and Caucasian women

    Science.gov (United States)

    D’Aloisio, Aimee A.; Schroeder, Jane C.; North, Kari E.; Poole, Charles; West, Suzanne L.; Travlos, Gregory S.; Baird, Donna D.

    2010-01-01

    Circulating insulin-like growth factor-one (IGF-I) and IGF binding protein-3 (IGFBP-3) levels have been associated with common diseases. Although family-based studies suggest that genetic variation contributes to circulating IGF-I and IGFBP-3 levels, analyses of associations with multiple IGF-I and IGFBP-3 single nucleotide polymorphisms (SNPs) have been limited, especially among African Americans. We evaluated 30 IGF-I and 15 IGFBP-3 SNPs and estimated diplotypes in association with plasma IGF-I and IGFBP-3 among 984 premenopausal African American and Caucasian women. In both races, IGFBP-3 rs2854746 (Ala32Gly) was positively associated with plasma IGFBP-3 (CC versus GG mean difference among Caucasians = 631 ng/ml, 95% confidence interval: 398, 864; African Americans = 897 ng/ml, 95% confidence interval: 656, 1138), and IGFBP-3 diplotypes with the rs2854746 GG genotype had lower mean IGFBP-3 levels than referent diplotypes with the CG genotype, while IGFBP-3 diplotypes with the CC genotype had higher mean IGFBP-3 levels. IGFBP-3 rs2854744 (−202 A/C) was in strong linkage disequilibrium with rs2854746 in Caucasians only, but was associated with plasma IGFBP-3 in both races. Eight additional IGFBP-3 SNPs were associated with 5% or greater differences in mean IGFBP-3 levels, with generally consistent associations between races. Twelve IGF-I SNPs were associated with 10% or greater differences in mean IGF-I levels, but associations were generally discordant between races. Diplotype associations with plasma IGF-I did not parallel IGF-I SNP associations. Our study supports that common IGFBP-3 SNPs, especially rs2854746, influence plasma IGFBP-3 levels among African Americans and Caucasians, but provides less evidence that IGF-I SNPs affect plasma IGF-I levels. PMID:19240240

  7. Bioactive insulin-like growth factor (IGF) I and IGF-binding protein-1 in anorexia nervosa

    DEFF Research Database (Denmark)

    Støving, René; Chen, Jian-Wen; Glintborg, Dorte

    2007-01-01

    CONTEXT: Regulation of IGF-I activity appears crucial in anorexia nervosa (AN) during adaptation to chronic starvation as well as during the regenerative processes on nutritional restoration. OBJECTIVE: The objective of this study was to examine the relationship between IGF-I bioactivity and IGF...

  8. Systemic administration of insulin-like growth factor I (IGF-I) causes growth of the rat prostate

    DEFF Research Database (Denmark)

    Tørring, N; Vinter-Jensen, L; Pedersen, S B

    1997-01-01

    -I after 3 days of treatment, and administration of IGF-I concomitantly with DFMO significantly inhibited ODC activity and the weight increase of the prostate. Stereological examination of the prostate in the IGF-I-treated animals showed growth of the epithelial component of the gland. Systemic treatment...

  9. Insulin and insulin-like growth factor-I (IGF-I) receptor phosphorylation in µ-calpain knockout mice

    Science.gov (United States)

    Numerous cellular processes are controlled by insulin and IGF-I signaling pathways. Due to previous work in our laboratories, we hypothesized that insulin (IR) and type 1 IGF-I (IGF-IR) receptor signaling is decreased due to increased protein tyrosine phosphatase 1B (PTP1B) activity. C57BL/6J mice...

  10. Effect of Insulin Infusion on insulin-like growth factor I (IGF-I) during Hemodialysis

    DEFF Research Database (Denmark)

    Reinhard, Mark; Frystyk, Jan; Bjerre, Mette

    2012-01-01

    Background: Hemodialysis (HD) is a catabolic procedure probably contributing to the high frequency of protein-energy wasting among patients on maintenance HD. The aim was to investigate the effect of insulin infusion on insulin-like growth factor I (IGF-I) during HD compared with a meal alone...... infusion and followed by the only meal allowed during the study. Results: Data are presented as mean±SD. From baseline to end of HD session we observed an overall increase in both serum bioactive IGF-I (from 0.83±0.27 to 1.01±0.34 µg/L, p... in the change between the groups (p=0.43). Conclusion: A meal at the beginning of a HD session leads to an increase in bioactive IGF-I thereby assumingly counteracting the catabolic effects of HD. However, according to changes in bioactive IGF-I neither glucose nor glucose-insulin infusion during HD appear...

  11. Hand size and growth in untreated and IGF-I treated patients with Laron syndrome.

    Science.gov (United States)

    Konen, O; Silbergeld, A; Lilos, P; Kornreich, L; Laron, Z

    2009-03-01

    We have previously reported on the linear growth, growth of the head circumference and foot length in untreated and IGF-I treated patients with Laron syndrome (LS) (primary GH insensitivity). To assess the size and growth of the hands in patients with LS from early childhood to adult age. Ten IGF-I treated children with LS (4 M, 6 F) and 24 untreated patients (10 M, 14 F) were studied. Measurements of palm length were made on available standardized hand X-rays from infancy to adult age. The measurements were compared to normal references and SD values were calculated for each measurement. The growth of the hand was compared to the concomitant height of the body. Hand SDS in untreated patients with LS decreased with age, from a mean of -2.8 +/- 0.7 (age 1-3 years) to -7.3 +/- 0.8 (age 13-15 years) and to -9.0 +/- 3.9 (age 40-50 years). During 9 years of IGF-I treatment the hand size deficit SDS did not improve in contradistinction to the height SDS which decreased from -6.2 +/- 1.2 to -3.9 +/- 0.5. Congenital IGF-I deficiency, as in Laron syndrome, profoundly affects the size and growth of the hand as part of its growth retardation characteristics, resulting in acromicria.

  12. Acute GH and IGF-I responses to short vs. long rest period between ...

    African Journals Online (AJOL)

    In order to examine the effects of different rest intervals between the sets on acute growth hormone (GH) and insulin-like growth factor-1 (IGF-I) responses, ten recreationally resistance trained men served as subjects (Mean ± SD, age=22 ± 2 years, body mass= 84 ± 8 kg). Subjects performed two heavy-resistance training ...

  13. Effects of High Intensity Interval Training on Plasma Levels of GH and IGF-I

    Directory of Open Access Journals (Sweden)

    Seyyed Mahmoud Hejazi

    2017-04-01

    Full Text Available Introduction: It is well-recognized that exercise has a significant impact on the GH/IGF system but less is known about the effects of HIIT on this axis. Aim of the present study was to evaluate the effect of ten weeks of HIIT on plasma levels of GH and IGF-I in healthy men. Methods: Twenty young men (age 23.34 ± 2.56 weight 72.47 ± 12.01 height 174.10 ± 5.75 recruited and randomly assigned into control (n=10 and HIIT (n=12 groups. HIIT protocol was started with 4 cycles. Then, every two weeks one cycle was added to the previous ones. Finally, it was to 8 cycles/ session in tenth weeks that lasted 16 minutes. Blood samples were collected prior to and after HIIT program for all subjects and IGF-I and GH levels were measured. Result: HIIT subjects showed a significant increase in IGF-I (P=0.002, F=12.38. However, no significant change was shown in GH levels (P=0.716, F=0.62. Discussion and conclusion: Our findings indicate that the HIIT caused increase in circulating levels of IGF-I independently from GH levels. Both hormones may contribute to positive effects of anabolic conditions.

  14. Acute regulation of IGF-I by alterations in post-exercise macronutrients

    Science.gov (United States)

    This investigation sought to examine the contributions of exercise and nutrient replenishment on in vivo regulation of the insulin-like growth factor-I (IGF-I) axis components. Eight college-aged males completed three high-intensity interval training (HIIT) protocols followed by three post-exercise ...

  15. IGF-I and IGFBP-3 levels and their correlations with ...

    African Journals Online (AJOL)

    Background: Colorectal cancer is one of the most frequently seen cancers worldwide. Currently, CEA is the most commonly used tumor marker in colorectal cancer. The changes in IGF/IGFBP equilibrium is also known to cause carcinogenesis. In this study, we aimed to monitor IGF-I/IGFBP-3 levels, the changes in ...

  16. High protein diets do not attenuate decrements in testosterone and IGF-I during energy deficit.

    Science.gov (United States)

    Henning, Paul C; Margolis, Lee M; McClung, James P; Young, Andrew J; Pasiakos, Stefan M

    2014-05-01

    Energy deficit (ED) diminishes fat-free mass (FFM) with concomitant reductions in anabolic hormone secretion. A modest increase in protein to recommended dietary allowance (RDA) levels during ED minimally attenuates decrements in insulin-like growth factor-I (IGF-I). The impact of dietary protein above the RDA on circulating anabolic hormones and their relationships with FFM in response to ED are not well described. Thirty-three adults were assigned diets providing protein at 0.8 (RDA), 1.6 (2×-RDA), and 2.4 (3×-RDA) g/kg/d for 31days. Testosterone, sex-hormone binding globulin (SHBG) and IGF-I system components were assessed after a 10-day period of weight-maintenance (WM) and after a 21-day period of ED (40%) achieved by an increase in energy expenditure and decreased energy intake. Associations between the change in FFM and anabolic hormone levels were determined. As compared to WM and regardless of dietary protein intake, total and free testosterone, total IGF-I, and acid-labile subunit decreased (Phormones or IGF-I system components measured. Changes in FFM in response to ED were negatively associated with acid-labile subunit (ALS) (r=-0.62, Phormone concentrations. Published by Elsevier Inc.

  17. IGF-I en la homeostasia cerebral: implicaciones patológicas

    Directory of Open Access Journals (Sweden)

    Ignacio Torres

    2005-03-01

    Full Text Available El factor de crecimiento de la familia de la insulina tipo I (IGF-I es una proteína sérica especialmente abundante fabricada principalmente en el hígado; su producción está regulada por la hormona de crecimiento (GH hipofisario.

  18. Sleep extension increases IGF-I concentrations before and during sleep deprivation in healthy young men.

    Science.gov (United States)

    Chennaoui, Mounir; Arnal, Pierrick J; Drogou, Catherine; Sauvet, Fabien; Gomez-Merino, Danielle

    2016-09-01

    Sleep deprivation is known to suppress circulating trophic factors such as insulin-like growth factor (IGF)-I and brain-derived neurotrophic factor (BDNF). This experiment examined the effect of an intervention involving 6 nights of extended sleep before total sleep deprivation on this catabolic profile. In a randomized crossover design, 14 young men (age range: 26-37 years) were either in an extended (EXT; time in bed: 2100-0700 h) or habitual (HAB: 2230-0700 h) sleep condition, followed by 3 days in the laboratory with blood sampling at baseline (B), after 24 h of sleep deprivation (24h-SD), and after 1 night of recovery sleep (R). In the EXT condition compared with the HAB condition, free IGF-I levels were significantly higher at B, 24h-SD, and R (P sleep deprivation was for insulin levels, which were significantly higher after R compared with B. In a healthy adult, additional sleep over 1 week increased blood concentrations of the anabolic factor IGF-I before and during 24 h of sleep deprivation and after the subsequent recovery night without effects on BDNF. With further research, these findings may prove to be important in guiding effective lifestyle modifications to limit physical or cognitive deficits associated with IGF-I decrease with age.

  19. IGF-I AND FGF-2 RESPONSES TO WINGATE ANAEROBIC TEST IN OLDER MEN

    Directory of Open Access Journals (Sweden)

    Ruthie Amir

    2007-06-01

    Full Text Available Reduced activity of the potent anabolic effectors: insulin-like growth factor-I (IGF-I and fibroblast growth factor-2 (FGF-2, play a role in aging associated muscle loss. The effect of fitness level on IGF-I and FGF-2 responses to all-out anaerobic exercise in older men was studied. Twenty four healthy older males: 12 higher fit (58 ± 1y and 12 lower fit (59 ± 1y underwent the Wingate anaerobic test. Serum levels of IGF-I and FGF-2 were measured before, immediately after exercise, and 50 min into recovery. Immediately post exercise, the average peak power output and serum lactate were higher (p < 0.05 in the higher fit (446.0 ± 14. 9 kgm·min-1 for mean (± SD peak power and 12.6 ± 1.1 mml·l-1 for lactate compared with the lower fit individuals (284.0 ± 6.5 kgm·min-1 and 8.5 ± 0.7 mml·l-1, respectively. Pre-exercise IGF-I was lower and FGF-2 was higher in the higher fit (335.0 ± 54.0 ng·ml-1 and 1.6 ± 0.1 ng·ml-1, respectively compared with lower fit individuals (402.0 ± 50.0 ng·ml-1 and 1.4 ± 0.2 ng·ml-1, respectively. Following the anaerobic exercise, in both groups, FGF-2 decreased dramatically (p < 0.05; in the higher fit individuals FGF-2 level was 0.4 ± 0.1 pg·ml-1 compared to 0.1 ± 0.02 pg·ml-1 in the lower fit individuals. In contrast to FGF-2, IGF-I increased transiently to levels of 405.0 ± 62.0 ng·ml-1 in the higher fit individuals and to levels of 436 ± 57.0 ng·ml-1 in the lower fit individuals. However, the IGF-I elevation was significant (p < 0. 05 only in the higher fit individuals. In conclusion, the present study demonstrates that during aging, fitness level can alter circulating levels of IGF-I and FGF-2. Furthermore, fitness level can affect the response of both mediators to all-out anaerobic exercise.

  20. Study on changes of serum leptin, IGF-I and IL-2 levels in elderly subjects with osteoporosis

    International Nuclear Information System (INIS)

    Sun Zihan; Luo Nanping; Niu Aijun; Qi Falian

    2006-01-01

    Objective: To investigate the changes of serum leptin, IGF-I and IL-2 levels in elderly subjects with osteoporosis. Methods: Serum leptin, IGF-I, IL-2 levels (with RIA), total cholesterol contents (with biochemical method) and bone mineral density (BMD) were examined in 65 aged patients with osteoporosis. Results: The serum leptin levels in subjects with osteoporosis were significantly higher than controls (P<0.01). The serum IGF-I and IL-2 levels in subjects with osteoporosis were significantly lower than those in controls (P<0.05, P<0.01). The BMD was positively correlated with the IGF-I levels and negatively correlated with leptin level. Conclusion: Derangement of leptin and IGF-I, IL-2 metabolism is one of the major causes of decreased bone mass and bone formation elderly subjects with osteoporosis. Measurement of serum levels of these parameters is of diagnostic help. (authors)

  1. IGFBP-1 and IGF-I as markers for advanced fibrosis in NAFLD - a pilot study.

    Science.gov (United States)

    Hagström, Hannes; Stål, Per; Hultcrantz, Rolf; Brismar, Kerstin; Ansurudeen, Ishrath

    2017-12-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease globally. Advanced fibrosis (stage 3-4) is the most robust marker for future mortality, but diagnosis requires liver biopsy. Current non-invasive scoring systems aimed to identify advanced fibrosis are imperfect. Insulin-like growth factor I (IGF-I) and its binding protein IGFBP-1 are liver derived proteins, that are involved in various liver disorders. The aim of this study was to examine the possible association between advanced fibrosis and IGF-I and IGFBP-1 in NAFLD. Fasting blood samples were obtained from 52 patients diagnosed with NAFLD by liver biopsy. Total IGF-I and IGFBP-1 concentrations were determined in serum by in-house radio-immuno-assays. IGF-I levels were age-standardized (IGF-SD). A logistic regression model was used to investigate the association of IGF-SD and IGFBP-1 with advanced fibrosis (stage 3-4). Patients with advanced fibrosis (stage 3-4 vs. 0-2) had lower IGF-SD (-1.17 vs. 0.11, p = .01) and higher mean levels of IGFBP-1 (29.9 vs. 18.8 µg/l, p = .02). IGFBP-1 was associated with presence of advanced fibrosis (OR 1.04 per unit increase, 95%CI 1.0-1.07, p = .05), while IGF-1 was negatively associated with advanced fibrosis (OR 0.63 per standard deviation, 95%CI 0.44-0.92, p = .02). This pilot study suggests an association between serum IGFBP-1 and IGF-I levels with advanced fibrosis in NAFLD patients. IGFBP1 and IGF-1 could be of interest as future biomarkers. Similar studies in larger cohorts are needed.

  2. Insulin/IGF-I regulation of necdin and brown adipocyte differentiation via CREB- and FoxO1-associated pathways

    DEFF Research Database (Denmark)

    Cypess, Aaron M; Zhang, Hongbin; Schulz, Tim J

    2011-01-01

    is regulated by the phosphoinositide 3 kinase-Akt pathway, increased necdin promoter activity. Based on reporter gene assays using truncations of the necdin promoter and chromatin immunoprecipitation studies, we demonstrated that CREB and FoxO1 are recruited to the necdin promoter, likely interacting......Brown adipose tissue plays an important role in obesity, insulin resistance, and diabetes. We have previously shown that the transition from brown preadipocytes to mature adipocytes is mediated in part by insulin receptor substrate (IRS)-1 and the cell cycle regulator protein necdin. In this study...... with specific consensus sequences in the proximal region. Based on these results, we propose that insulin/IGF-I act through IRS-1 phosphorylation to stimulate differentiation of brown preadipocytes via two complementary pathways: 1) the Ras-ERK1/2 pathway to activate CREB and 2) the phosphoinositide 3 kinase-Akt...

  3. Treatment with N- and C-Terminal Peptides of Parathyroid Hormone-Related Protein Partly Compensate the Skeletal Abnormalities in IGF-I Deficient Mice

    Science.gov (United States)

    Portal-Núñez, Sergio; Murillo-Cuesta, Silvia; Lozano, Daniel; Cediel, Rafael; Esbrit, Pedro

    2014-01-01

    Insulin-like growth factor-I (IGF-I) deficiency causes growth delay, and IGF-I has been shown to partially mediate bone anabolism by parathyroid hormone (PTH). PTH-related protein (PTHrP) is abundant in bone, and has osteogenic features by poorly defined mechanisms. We here examined the capacity of PTHrP (1–36) and PTHrP (107–111) (osteostatin) to reverse the skeletal alterations associated with IGF-I deficiency. Igf1-null mice and their wild type littermates were treated with each PTHrP peptide (80 µg/Kg/every other day/2 weeks; 2 males and 4 females for each genotype) or saline vehicle (3 males and 3 females for each genotype). We found that treatment with either PTHrP peptide ameliorated trabecular structure in the femur in both genotypes. However, these peptides were ineffective in normalizing the altered cortical structure at this bone site in Igf1-null mice. An aberrant gene expression of factors associated with osteoblast differentiation and function, namely runx2, osteoprotegerin/receptor activator of NF-κB ligand ratio, Wnt3a , cyclin D1, connexin 43, catalase and Gadd45, as well as in osteocyte sclerostin, was found in the long bones of Igf1-null mice. These mice also displayed a lower amount of trabecular osteoblasts and osteoclasts in the tibial metaphysis than those in wild type mice. These alterations in Igf1-null mice were only partially corrected by each PTHrP peptide treatment. The skeletal expression of Igf2, Igf1 receptor and Irs2 was increased in Igf1-null mice, and this compensatory profile was further improved by treatment with each PTHrP peptide related to ERK1/2 and FoxM1 activation. In vitro, PTHrP (1–36) and osteostatin were effective in promoting bone marrow stromal cell mineralization in normal mice but not in IGF-I-deficient mice. Collectively, these findings indicate that PTHrP (1–36) and osteostatin can exert several osteogenic actions even in the absence of IGF-I in the mouse bone. PMID:24503961

  4. Insulin Resistance and the IGF-I-Cortical Bone Relationship in Children Ages 9 to 13 Years.

    Science.gov (United States)

    Kindler, Joseph M; Pollock, Norman K; Laing, Emma M; Oshri, Assaf; Jenkins, Nathan T; Isales, Carlos M; Hamrick, Mark W; Ding, Ke-Hong; Hausman, Dorothy B; McCabe, George P; Martin, Berdine R; Hill Gallant, Kathleen M; Warden, Stuart J; Weaver, Connie M; Peacock, Munro; Lewis, Richard D

    2017-07-01

    IGF-I is a pivotal hormone in pediatric musculoskeletal development. Although recent data suggest that the role of IGF-I in total body lean mass and total body bone mass accrual may be compromised in children with insulin resistance, cortical bone geometric outcomes have not been studied in this context. Therefore, we explored the influence of insulin resistance on the relationship between IGF-I and cortical bone in children. A secondary aim was to examine the influence of insulin resistance on the lean mass-dependent relationship between IGF-I and cortical bone. Children were otherwise healthy, early adolescent black and white boys and girls (ages 9 to 13 years) and were classified as having high (n = 147) or normal (n = 168) insulin resistance based on the homeostasis model assessment of insulin resistance (HOMA-IR). Cortical bone at the tibia diaphysis (66% site) and total body fat-free soft tissue mass (FFST) were measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA), respectively. IGF-I, insulin, and glucose were measured in fasting sera and HOMA-IR was calculated. Children with high HOMA-IR had greater unadjusted IGF-I (p insulin resistance as a potential suppressor of IGF-I-dependent cortical bone development, though prospective studies are needed. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  5. The IGF-I/IGFBP-3 system in gingival crevicular fluid and dependence on application of fixed force.

    Science.gov (United States)

    Toia, M; Galazzo, R; Maioli, C; Granata, R; Scarlatti, F

    2005-12-01

    During application of orthodontic force on the tooth, various molecular parameters associated with tissue remodeling are changed. IGF-I is a regulatory protein produced during periodontal regeneration. IGF binding proteins-3 (IGFBP-3), a specific IGF-I binding protein, is the major regulatory factor of IGF-I activity. We tested the hypothesis that changes in the IGF-I/ IGFBP-3 system occur during fixed force application to the tooth and that these changes are detectable in the gingival crevicular fluid (GCF). IGFBP-3 and IGF-I secretion into gingival crevicular fluid (GCF) was analyzed by Western blotting and immunoradiometric assay (IRMA), respectively, in GCF of 6 healthy subjects just prior to and during orthodontics treatment using fixed appliances. We observed a significant time-dependent decrease of IGFBP-3 content in GCF during orthodontic treatment (4 h and 10 days). Reduction in levels of intact, glycosylated 47 kDa form of IGFBP-3 was associated with its degradation and the appearance of intermediate breakdown products. IGF-I levels were significantly increased 4 h after application of orthodontic force, while they were significantly reduced 10 days after the start of treatment. IGFBP-3 secretion into GCF and its molecular structure are modified by the fixed force of orthodontic treatment. Alterations in IGFBP-3 appear to be unrelated to the binding to IGF-I, suggesting an IGF-independent role of this binding protein in tooth movement.

  6. IGF-I treatment improves the functional properties of fast- and slow-twitch skeletal muscles from dystrophic mice.

    Science.gov (United States)

    Lynch, G S; Cuffe, S A; Plant, D R; Gregorevic, P

    2001-04-01

    Although insulin-like growth factor-I (IGF-I) has been proposed for use by patients suffering from muscle wasting conditions, few studies have investigated the functional properties of dystrophic skeletal muscle following IGF-I treatment. 129P1 ReJ-Lama2(dy) (129 ReJ dy/dy) dystrophic mice suffer from a deficiency in the structural protein, laminin, and exhibit severe muscle wasting and weakness. We tested the hypothesis that 4 weeks of IGF-I treatment ( approximately 2 mg/kg body mass, 50 g/h via mini-osmotic pump, subcutaneously) would increase the mass and force producing capacity of skeletal muscles from dystrophic mice. IGF-I treatment increased the mass of the extensor digitorum longus (EDL) and soleus muscles of dystrophic mice by 20 and 29%, respectively, compared with untreated dystrophic mice (administered saline-vehicle only). Absolute maximum force (P(o)) of the EDL and soleus muscle was increased by 40 and 32%, respectively, following IGF-I treatment. Specific P(o) (sP(o)) was increased by 23% in the EDL muscles of treated compared with untreated mice, but in the soleus muscle sP(o) was unchanged. IGF-I treatment increased the proportion of type IIB and type IIA fibres and decreased the proportion of type I fibres in the EDL muscles of dystrophic mice. In the soleus muscles of dystrophic mice, IGF-I treatment increased the proportion of type IIA fibres and decreased the proportion of type I fibres. Average fibre cross-sectional area was increased in the EDL and soleus muscles of treated compared with untreated mice. We conclude that IGF-I treatment ameliorates muscle wasting and improves the functional properties of skeletal muscles of dystrophic mice. The findings have important implications for the role of IGF-I in ameliorating muscle wasting associated with the muscular dystrophies.

  7. Altered expression of IGF-I system in neurons of the inflamed spinal cord during acute experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Parvaneh Tafreshi, Azita; Talebi, Farideh; Ghorbani, Samira; Bernard, Claude; Noorbakhsh, Farshid

    2017-10-01

    There is growing evidence that the impaired IGF-I system contributes to neurodegeneration. In this study, we examined the spinal cords of the EAE, the animal model of multiple sclerosis, to see if the expression of the IGF-I system is altered. To induce EAE, C57/BL6 mice were immunized with the Hooke lab MOG kit, sacrificed at the peak of the disease and their spinal cords were examined for the immunoreactivities (ir) of the IGF-I, IGF binding protein-1 (IGFBP-1) and glycogen synthase kinase 3β (GSK3β), as one major downstream molecule in the IGF-I signaling. Although neurons in the non EAE spinal cords did not show the IGF-I immunoreactivity, they were numerously positive for the IGFBP-1. In the inflamed EAE spinal cord however, the patterns of expressions were reversed, that is, a significant increased number of IGF-I expressing neurons versus a reduced number of IGFBP-1 positive neurons. Moreover, while nearly all IGF-I-ir neurons expressed GSK3β, some expressed it more intensely. Considering our previous finding where we showed a significant reduced number of the inactive (phosphorylated) but not that of the total GSK3β expressing neurons in the EAE spinal cord, it is conceivable that the intense total GSK3β expression in the IGF-I-ir neurons belongs to the active form of GSK3β known to exert neuroinflammatory effects. We therefore suggest that the altered expression of the IGF-I system including GSK3β in spinal cord neurons might involve in pathophysiological events during the EAE. © 2017 Wiley Periodicals, Inc.

  8. Gender and age influence the relationship between serum GH and IGF-I in patients with acromegaly.

    Science.gov (United States)

    Parkinson, C; Renehan, A G; Ryder, W D J; O'Dwyer, S T; Shalet, S M; Trainer, P J

    2002-07-01

    In patients with acromegaly serum IGF-I is increasingly used as a marker of disease activity. As a result, the relationship between serum GH and IGF-I is of profound interest. Healthy females secrete three times more GH than males but have broadly similar serum IGF-I levels, and women with GH deficiency require 30-50% more exogenous GH to maintain the same serum IGF-I as GH-deficient men. In a selected cohort of patients with active acromegaly, studied off medical therapy using a single fasting serum GH and IGF-I measurement, we have reported previously that, for a given GH level, women have significantly lower circulating IGF-I. To evaluate the influence of age and gender on the relationship between serum GH and IGF-I in an unselected cohort of patients with acromegaly independent of disease control and medical therapy. Sixty (34 male) unselected patients with acromegaly (median age 51 years (range 24-81 years) attending a colonoscopy screening programme were studied. Forty-five had previously received pituitary radiotherapy. Patients had varying degrees of disease control and received medical therapy where appropriate. Mean serum GH was calculated from an eight-point day profile (n = 45) and values obtained during a 75-g oral glucose tolerance test (n = 15). Serum IGF-I, IGFBP-3 and acid-labile subunit were measured and the dependency of these factors on covariates such as log10 mean serum GH, sex, age and prior radiotherapy was assessed using regression techniques. The median calculated GH value was 4.7 mU/l (range 1-104). A significant linear association was observed between serum IGF-I and log10 mean serum GH for the cohort (R = 0.5, P fall by 0.37 nmol/l per year (P = 0.04, 95% CI 0.015-0.72). In keeping with previous observations of relative GH resistance in normal and GH-deficient females we have observed lower serum IGF-I levels for equivalent mean serum GH levels in females patients with acromegaly. This gender-dependent difference is independent of

  9. Elevated serum IGF-I, but unaltered sex steroid levels, in healthy boys with pubertal gynaecomastia

    DEFF Research Database (Denmark)

    Mieritz, Mikkel G; Sorensen, Kaspar; Aksglaede, Lise

    2014-01-01

    OBJECTIVE: Pubertal gynaecomastia is a very common condition. Although the underlying aetiology is poorly understood, it is generally accepted that excess of oestrogens and deficit of androgens are involved in the pathogenesis. Furthermore, adiposity as well as the GH/IGF-I axis may play a role....... In this study, we elucidate the association of adiposity and levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), testosterone, oestrogen, IGF-I and IGFBP-3 with the presence of pubertal gynaecomastia in a large cohort of healthy boys. PATIENTS: A total...... of 501 healthy Danish school boys (aged 6·1-19·8 year) from the COPENHAGEN Puberty Study. MEASUREMENTS: Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Body fat percentage was calculated by means of four skin folds and impedance...

  10. Changes in IGF-I and its Binding Proteins Are Associated with Diabetes in Older Adults

    Science.gov (United States)

    Aneke, Chino S.; Parrinello, Christina M.; Rajpathak, Swapnil N.; Rohan, Thomas E.; Strotmeyer, Elsa S.; Kritchevsky, Stephen B.; Psaty, Bruce M.; Bůžková, Petra; Kizer, Jorge R.; Newman, Anne B.; Strickler, Howard D.; Kaplan, Robert C.

    2015-01-01

    Objectives Little is known about long-term changes in insulin-like growth Factor (IGF) proteins and glycemic status. We hypothesized that changes in IGF proteins are exaggerated in participants with type 2 diabetes or worsening glycemia versus those that remain normoglycemic over a 9-year follow-up period. Design Retrospective analysis of cohort study. Setting Participants were recruited from four States: North Carolina, California, Maryland and Pennsylvania. Participants 897 participants enrolled in CHS All Stars, a cohort study of community dwelling adults aged ≥65 years. Measurements Plasma IGF-I, IGFBP-1, and IGFBP-3 levels were assessed and ADA cut-points for IGT, IFG, and diabetes were used to classify participants at baseline (1996–1997) and follow-up (2005–2006). Results At baseline, mean age was 76.3 years (± 3.6) and 18.5% had diabetes. Individuals with IFG alone and IGT+IFG had the highest levels of IGF-I and lowest levels of IGFBP-1, compared to individuals with normoglycemia or diabetes. The greatest percent change in IGF levels occurred in those who had diabetes at baseline (9-year changes: −9.3% for IGF-I, 59.7% for IGFBP-1, −13.4% for IGFBP-3); the smallest in individuals who remained normoglycemic at follow-up (9-year changes: −3.7% for IGF-I, 25.6% for IGFBP-1, −6.4% for IGFBP-3); and intermediate changes in those who were normoglycemic but developed IFG at follow-up. Conclusion Our results demonstrate that degrees of glycemic impairment are associated with varying levels of changes in IGF proteins. The exaggerated changes observed in the diabetes group have been previously shown to be associated with heart failure, cancer and non-cancer mortality. PMID:25989565

  11. IGF-I during primiparous pregnancy and maternal risk of breast cancer

    OpenAIRE

    Chen, Tianhui; Lukanova, Annekatrin; Grankvist, Kjell; Zeleniuch-Jacquotte, Anne; Wulff, Marianne; Johansson, Robert; Schock, Helena; Lenner, Per; Hallmans, Goran; Wadell, Goran; Toniolo, Paolo; Lundin, Eva

    2009-01-01

    Abstract Previously, we reported that insulin-like growth factor (IGF)-I during early pregnancy is positively associated with maternal risk of breast cancer. To further explore this association, we designed a new study limited to women who donated a blood sample during their first pregnancy ending with childbirth. A case?control study was nested within the Northern Sweden Maternity Cohort in which repository since 1975, serum specimens remaining after early pregnancy screening for ...

  12. IGF-I deficiency, longevity and cancer protection of patients with Laron syndrome.

    Science.gov (United States)

    Laron, Zvi; Kauli, Rivka; Lapkina, Lena; Werner, Haim

    Laron syndrome (LS) is a unique model of congenital IGF-I deficiency. It is characterized by dwarfism and obesity, and is caused by deletion or mutations of the growth hormone receptor (GH-R) gene. It is hypothesized that LS is an old disease originating in Indonesia and that the mutated gene spread to South Asia, the Middle East, the Mediterranean region and South America. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. High intakes of skimmed milk, but not meat, increase serum IGF-I and IGFBP-3 in eight-year-old boys

    DEFF Research Database (Denmark)

    Hoppe, C.; Mølgaard, C; Juul, A.

    2004-01-01

    To examine whether a high protein intake (PI) from either milk or meat, at a level often seen in late infancy, could increase s-IGF-I and s-IGF-I/s-IGFBP-3 in healthy, prepubertal children. IGF-I levels are positively associated with growth velocity in children and some studies suggest that a high...... animal PI can stimulate growth. During protein deprivation IGF-I decrease, but it is unknown whether a high PI can increase s-IGF-I in well-nourished children....

  14. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  15. Differential effects of hGH and IGF-I on body proportions.

    Science.gov (United States)

    Laron, Zvi; Silbergeld, Aviva; Kauli, Rivka

    2012-07-01

    The differential growth effects of hGH and IGF-I on the upper/lower (U/L) body segment in relation to height (Ht) were analyzed in 15 patients with isolated Growth hormone deficiency (IGHD,:7M, 8F) mean age 5.0 +/- 3.2 (SD) years treated with hGH; 21 patients with multiple pituitary hormone deficiency including growth hormone (MPHD: 14M, 7F) aged 10.0 +/- 3.8, treated with hGH; 9 patients with Laron Syndrome (LS) (4M,5F) aged 6.9 +/- 5.6 years treated with IGF-I; 9 boys with intrauterine growth retardation (IUGR) aged 6.3 +/- 1.25 years treated by hGH; and 22 boys with idiopathic short stature (ISS) aged 8.0 +/- 1.55 years treated by hGH. The dose of hGH was 33 microg/kg/day, that of IGF-I 180-200 microg/kg/day. the U/L body segment ratio in IGHD patients decreased from 2.3 +/- 0.7 to 1.1 +/- 0.7 (p <0.001), and the Ht SDS increased from -4.9 +/- 1.3 to 2.3 +/- 1 (p < 0.001) following treatment. In MPHD patients the U/L body segment decreased from 1.1 +/- 1.1 to -0.6 +/- 1.0 (p < 0.001), and the Ht SDS increased from -3.3 +/- 1.4 to -2.5 +/- 1.0 (p < 0.009). In the LS group the U/L body segment ratio did not change with IGF-I treatment but Ht improved from -6.1 +/- 1.3 to -4.6 +/- 1.2 (p < 0.001), The differential growth response of the children with IUGR and with ISS resembled that of the children with LS. hGH and IGF-I act differentially on the spine and limbs.

  16. Endurance training-induced changes in the GH-IGF-I axis influence maximal muscle strength in previously untrained men.

    Science.gov (United States)

    Grandys, Marcin; Majerczak, Joanna; Kuczek, Piotr; Sztefko, Krystyna; Duda, Krzysztof; Zoladz, Jerzy A

    2017-02-01

    In this study we have determined the effects of 20weeks of endurance running training on the GH-IGF-I axis changes in the context of the skeletal muscle performance and physical capacity level. Before and after the endurance training program a maximal incremental exercise tests, a 1500m race and a muscle strength measurements were performed and the blood samples were taken to determine both resting as well as end-exercise serum growth hormone (GH), insulin-like growth hormone-I (IGF-I), insulin-like growth hormone binding protein-3 (IGFBP-3) and plasma interleukin-6 (IL-6) concentrations. 20weeks of endurance running training improved power output generated at the end of the maximal incremental test by 24% (P<0.012), 1500m running time by 13% (P<0.012) and maximal muscle strength by 9% (P<0.02). End-exercise IGF-I/IGFBP-3 ratio was decreased by 22% after the training (P<0.04) and the magnitude of IGF-I/IGFBP-3 ratio decrease (ΔIGF-I/IGFBP-3 ex ) was 2.3 times higher after the training (P<0.04). The magnitude of the exercise-induced changes in IGFBP-3 concentration was also significantly higher (P<0.04) and there was a trend toward lower end-exercise IGF-I concentration (P=0.08) after the training. These changes were accompanied by a significantly higher (30%) end-exercise IL-6 concentration (P<0.01) as well as by a 3.4 times higher magnitude of IL-6 increase (P<0.02) after the training. Moreover, there were strong positive correlations between changes in resting serum IGF-I concentration (ΔIGF-I res ) and IGF-I/IGFBP-3 ratio (ΔIGF-I/IGFBP-3 res ) and changes in muscle strength (ΔMVC) (r=0.95, P=0.0003 and r=0.90, P=0.002, respectively). The training-induced changes in the components of the GH-IGF-I axis may have additive effects on skeletal muscle performance and physical capacity improvement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Children with severe Osteogenesis imperfecta and short stature present on average with normal IGF-I and IGFBP-3 levels.

    Science.gov (United States)

    Hoyer-Kuhn, Heike; Höbing, Laura; Cassens, Julia; Schoenau, Eckhard; Semler, Oliver

    2016-07-01

    Osteogenesis imperfecta (OI) is characterized by bone fragility and short stature. Data about IGF-I/IGFBP-3 levels are rare in OI. Therefore IGF-I/IGFBP-3 levels in children with different types of OI were investigated. IGF-I and IGFBP-3 levels of 60 children (male n=38) were assessed in a retrospective cross-sectional setting. Height/weight was significant different [height z-score type 3 versus type 4: p=0.0011 and weight (p≤0.0001)] between OI type 3 and 4. Mean IGF-I levels were in the lower normal range (mean±SD level 137.4±109.1 μg/L). Mean IGFBP-3 measurements were in the normal range (mean±SD 3.105±1.175 mg/L). No significant differences between OI type 3 and 4 children have been observed (IGF-I: p=0.0906; IGFBP-3: p=0.2042). Patients with different severities of OI have IGF-I and IGFBP-3 levels in the lower normal range. The type of OI does not significantly influence these growth factors.

  18. Serum insulin-like growth factor 1(IGF-I) and prostatic cancer risk a retrospective study

    International Nuclear Information System (INIS)

    Li Liren; Liu Jiumin; Lu Bailing

    2001-01-01

    Objective: To investigate the relationship between serum IGF-I levels and prostatic cancer. Methods: Serum IGF-I levels were determined by immunoradiometric assay (IRMA) in 30 cases of prostatic cancer, 30 cases of benign prostatic hyperplasia (BPH) and 30 healthy subjects as controls. Results: The mean levels of serum IGF-I in prostatic cancer (148 +- 49.6 μg/L) were significantly higher than those in BPH (91.0 +- 32.8 μg/L) and healthy subjects (105 +- 25.6 μg/L) (P 0.05). The IGF-I levels were not relates to BHP, but increased values of IGF-I were associated with increased risk of prostatic cancer. The odds ratio was 11.23 for patients of prostatic cancer compared with healthy subjects, (95 percent confidence interval 3.09 - 40.7). Conclusion: This finding suggests that high IGF-I may be associated with increase risk of prostate cancer in human

  19. The DNA methylation status of MyoD and IGF-I genes are correlated with muscle growth during different developmental stages of Japanese flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Huang, Yajuan; Wen, Haishen; Zhang, Meizhao; Hu, Nan; Si, Yufeng; Li, Siping; He, Feng

    2018-05-01

    Many genes related to muscle growth modulate myoblast proliferation and differentiation and promote muscle hypertrophy. MyoD is a myogenic determinant that contributes to myoblast determination, and insulin-like growth factor 1 (IGF-I) interacts with MyoD to regulate muscle hypertrophy and muscle mass. In this study, we aimed to assess DNA methylation and mRNA expression patterns of MyoD and IGF-I during different developmental stages of Japanese flounder, and to examine the relationship between MyoD and IGF-I gene. DNA and RNA were extracted from muscles, and DNA methylation of MyoD and IGF-I promoter and exons was detected by bisulfite sequencing. The relative expression of MyoD and IGF-I was measured by quantitative polymerase chain reaction. IGF-I was measured by radioimmunoassay. Interestingly, the lowest expression of MyoD and IGF-I emerged at larva stage, and the mRNA expression was negatively associated with methylation. We hypothesized that many skeletal muscle were required to complete metamorphosis; thus, the expression levels of MyoD and IGF-I genes increased from larva stage and then decreased. The relative expression levels of MyoD and IGF-I exhibited similar patterns, suggesting that MyoD and IGF-I regulated muscle growth through combined effects. Changes in the concentrations of IGF-I hormone were similar to those of IGF-I gene expression. Our results the mechanism through which MyoD and IGF-I regulate muscle development and demonstrated that MyoD interacted with IGF-I to regulate muscle growth during different developmental stages. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. The Effects of Systemic IGF-I on the Arterial Anastomosis in Rats

    Directory of Open Access Journals (Sweden)

    Baris Keklik

    2014-04-01

    Full Text Available Objective: In this study, we aimed to document the effects of a well-known agent and mdash; and ldquo;insulin-like growth factor (IGF-I and rdquo; and mdash; on the microvascular anastomosis site. Methods: Sixteen Sprague-Dawley rats were used in this study. The rats were classified randomly into two equally numbered groups (eight rats each: the control (Group 1 and the experiment group (Group 2. The femoral artery was dissected completely in all rats. Following division of the artery, anastomoses were conducted with microvascular techniques. Forty-five minutes after the anastomoses, an Acland milking test was performed in order to check the patency and the first surgical session was terminated. In the second stage, LONG and reg; R3 IGF-I human (Sigma-Aldrich, St. Louis, Missouri, United States solution was introduced to Group 2 (experimental group intraperitoneally in doses of 2 mg/kg on the day of the surgery in addition to the third and seventh days postoperatively. On the 4th postoperative week, the patency of the anastomoses was evaluated with the Acland milking test. In addition, one centimeter of a vascular segment including the anastomosis site was excised and stained with hematoxylin-eosin. They were evaluated for edema, inflammation, vascular wall injury, intimal hyperplasia, medial atrophy, thrombus, calcification, foreign body reactions, and the endothelial proliferation. Results: The Acland milking test showed a 100% vascular patency in both groups. A statistically significant difference was found between the experimental and control groups in terms of edema and vascular wall injury (p0.05. Conclusion: Under the light of the obtained data, IGF-I was effective in preventing the edema and vascular wall injury at the anastomosis site. However, the net positive clinical effect on anastomosis patency necessitates further studies. [Arch Clin Exp Surg 2014; 3(2.000: 87-93

  1. Effects of High Intensity Interval Training on Plasma Levels of GH and IGF-I

    OpenAIRE

    Seyyed Mahmoud Hejazi

    2017-01-01

    Introduction: It is well-recognized that exercise has a significant impact on the GH/IGF system but less is known about the effects of HIIT on this axis. Aim of the present study was to evaluate the effect of ten weeks of HIIT on plasma levels of GH and IGF-I in healthy men. Methods: Twenty young men (age 23.34 ± 2.56 weight 72.47 ± 12.01 height 174.10 ± 5.75) recruited and randomly assigned into control (n=10) and HIIT (n=12) groups. HIIT protocol was started with 4 cycles. Then,...

  2. SERUM IGF-I AND HORMONAL RESPONSES TO INCREMENTAL EXERCISE IN ATHLETES WITH AND WITHOUT LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    Aleksandra Zebrowska

    2009-03-01

    Full Text Available We investigated the response of insulin-like growth factor (IGF- I, insulin-like growth factor binding protein-3 (IGFBP-3 and some hormones, i.e., testosterone (T, growth hormone (GH, cortisol (C, and insulin (I, to maximal exercise in road cyclists with and without diagnosed left ventricular hypertrophy. M-mode and two-dimensional Doppler echocardiography was performed in 30 professional male endurance athletes and a group of 14 healthy untrained subjects using a Hewlett-Packard Image Point HX ultrasound system with standard imaging transducers. Echocardiography and an incremental physical exercise test were performed during the competitive season. Venous blood samples were drawn before and immediately after the maximal cycling exercise test for determination of somatomedin and hormonal concentrations. The basal concentration of IGF-I was statistically higher (p < 0.05 in athletes with left ventricular muscle hypertrophy (LVH when compared to athletes with a normal upper limit of the left ventricular wall (LVN (p < 0.05 and to the control group (CG (p < 0.01. The IGF-I level increased significantly at maximal intensity of incremental exercise in CG (p < 0.01, LVN (p < 0.05 and LVH (p < 0.05 compared to respective values at rest. Long-term endurance training induced an increase in resting (p < 0.01 and post-exercise (p < 0.05 IGF-I/IGFBP-3 ratio in athletes with LVH compared to LVN. The testosterone (T level was lower in LVH at rest compared to LVN and CG groups (p < 0.05. These results indicate that resting serum IGF-I concentration were higher in trained subjects with LVH compared to athletes without LVH. Serum IGF- I/IGFBP-3 elevation at rest and after exercise might suggest that IGF-I act as a potent stimulant of left ventricular hypertrophy in chronically trained endurance athletes

  3. Secondhand Smoke Exposure Reduced the Compensatory Effects of IGF-I Growth Signaling in the Aging Rat Hearts.

    Science.gov (United States)

    Wu, Jia-Ping; Hsieh, Dennis Jine-Yuan; Kuo, Wei-Wen; Han, Chien-Kuo; Pai, Peiying; Yeh, Yu-Lan; Lin, Chien-Chung; Padma, V Vijaya; Day, Cecilia Hsuan; Huang, Chih-Yang

    2015-01-01

    Secondhand smoke (SHS) exposure is associated with increased risk of cardiovascular disease. Aging is a physiological process that involves progressive impairment of normal heart functions due to increased vulnerability to damage. This study examines secondhand smoke exposure in aging rats to determine the age-related death-survival balance. Rats were placed into a SHS exposure chamber and exposed to smog. Old age male Sprague-Dawley rats were exposed to 10 cigarettes for 30 min, day and night, continuing for one week. After 4 weeks the rats underwent morphological and functional studies. Left ventricular sections were stained with hematoxylin-eosin for histopathological examination. TUNEL detected apoptosis cells and protein expression related death and survival pathway were analyzed using western blot. Death receptor-dependent apoptosis upregulation pathways and the mitochondria apoptosis proteins were apparent in young SHS exposure and old age rats. These biological markers were enhanced in aging SHS-exposed rats. The survival pathway was found to exhibit compensation only in young SHS-exposed rats, but not in the aging rats. Further decrease in the activity of this pathway was observed in aging SHS-exposed rats. TUNEL apoptotic positive cells were increased in young SHS-exposed rats, and in aging rats with or without SHS-exposure. Aging reduces IGF-I compensated signaling with accelerated cardiac apoptotic effects from second-hand smoke.

  4. Circulating levels of insulin-like growth factor-I (IGF-I correlate with disease status in leprosy

    Directory of Open Access Journals (Sweden)

    Rodrigues Luciana

    2011-12-01

    Full Text Available Abstract Background Caused by Mycobacterium leprae (ML, leprosy presents a strong immune-inflammatory component, whose status dictates both the clinical form of the disease and the occurrence of reactional episodes. Evidence has shown that, during the immune-inflammatory response to infection, the growth hormone/insulin-like growth factor-I (GH/IGF-I plays a prominent regulatory role. However, in leprosy, little, if anything, is known about the interaction between the immune and neuroendocrine systems. Methods In the present retrospective study, we measured the serum levels of IGF-I and IGBP-3, its major binding protein. These measurements were taken at diagnosis in nonreactional borderline tuberculoid (NR BT, borderline lepromatous (NR BL, and lepromatous (NR LL leprosy patients in addition to healthy controls (HC. LL and BL patients who developed reaction during the course of the disease were also included in the study. The serum levels of IGF-I, IGFBP-3 and tumor necrosis factor-alpha (TNF-α were evaluated at diagnosis and during development of reversal (RR or erythema nodosum leprosum (ENL reaction by the solid phase, enzyme-labeled, chemiluminescent-immunometric method. Results The circulating IGF-I/IGFBP-3 levels showed significant differences according to disease status and occurrence of reactional episodes. At the time of leprosy diagnosis, significantly lower levels of circulating IGF-I/IGFBP-3 were found in NR BL and NR LL patients in contrast to NR BT patients and HCs. However, after treatment, serum IGF-I levels in BL/LL patients returned to normal. Notably, the levels of circulating IGF-I at diagnosis were low in 75% of patients who did not undergo ENL during treatment (NR LL patients in opposition to the normal levels observed in those who suffered ENL during treatment (R LL patients. Nonetheless, during ENL episodes, the levels observed in RLL sera tended to decrease, attaining similar levels to those found in NR LL patients

  5. Changes of blood and myocardial tissue contents of IGF-I after development of acute myocardial infarction in rat models

    International Nuclear Information System (INIS)

    Cao Heng; Wei Youquan

    2006-01-01

    Objective: To study the changes of IGF-I contents in blood and myocardium after experimental acute myocardial infarction in rat models. Methods: Rat models of acute myocardial infarction were prepared with intraperitoneal injection of isoproterenol. Eight models were sacrificed 48h later and another 8 models were sacrificed 14 days after preparation. Serum and myocardium homogenate contents of IGF-I were measured with RIA in these models as well as 8 control rats. Results: The serum and myocardial contents of IGF-I increased in the models sacrificed at 48h, but were not significantly higher than those in the controls (P>0.05). At 14 th day, the levels were significantly higher than those in controls and at 48h (both P<0.05). The serum and myocardial contents of IGF-I were mutually correlated in the controls and 14 day models (r=0.9987, r=0.9992; P<0.01). Conclusion After myocardial infarction, the serum and myocardial IGF-I contents increased along with the course of disease in the rat models. (authors)

  6. Expression of IGF-I and Protein Degradation Markers During Hindlimb Unloading and Growth Hormone Administration in Rats

    Science.gov (United States)

    Leinsoo, T. A.; Turtikova, O. V.; Shenkman, B. S.

    2013-02-01

    It is known that hindlimb unloading or spaceflight produce atrophy and a number of phenotypic alterations in skeletal muscles. Many of these processes are triggered by the axis growth hormone/insulin-like growth factor I. However growth hormone (GH) and insulin-like growth factor I (IGF-I) expression relationship in rodent models of gravitational unloading is weakly investigated. We supposed the IGF-I is involved in regulation of protein turnover. In this study we examined the IGF-I expression by RT-PCR assay in the rat soleus, tibialis anterior and liver after 3 day of hindlimb suspension with growth hormone administration. Simultaneously were studied expression levels of MuRF-1 and MAFbx/atrogin as a key markers of intracellular proteolysis. We demonstrated that GH administration did not prevent IGF-I expression decreasing under the conditions of simulated weightlessness. It was concluded there are separate mechanisms of action of GH and IGF-I on protein metabolism in skeletal muscles. Gravitational unloading activate proteolysis independently of growth hormone activity.

  7. Coordinated increase in skeletal muscle fiber area and expression of IGF-I with resistance exercise in elderly post-operative patients

    DEFF Research Database (Denmark)

    Suetta, Charlotte; Clemmensen, Christoffer; Andersen, Jesper L

    2010-01-01

    Hypertrophy of developing skeletal muscle involves stimulation by insulin-like growth factor-I (IGF-I), however, the role of IGF-I in adult muscle is less clarified. In the present study, the mRNA splice variants of IGF-I (IGF-IEa and MGF) and the changes in muscle fiber cross sectional area after...... and in addition induces marked increases in the expression of IGF-I splice variants, supporting the idea that IGF-I is involved in regulating muscle hypertrophy.......-operated-side served as a within subject control. Muscle biopsies were obtained from the vastus lateralis of both limbs at +2d post-operative (baseline), at 5weeks and 12weeks post-surgery to analyze for changes in type 1 and type 2 muscle fiber area. Changes in expression levels of IGF-I mRNA isoforms were determined...

  8. Hypoxic-cell sensitizers

    International Nuclear Information System (INIS)

    Dische, S.

    1983-01-01

    There is now 6 years of clinical experience with misonidazole as a hypoxic-cell sensitizer. Neurotoxicity limits the total dose which may be given, and so relatively low concentrations of radiosensitizing drugs are likely to be achieved in hypoxic cells in man as compared with those in animal tumors. It is likely that benefit will only be shown in those situations where radioresistant hypoxic cells strongly dominate as a cause of radiation failure. Many clinical trials are underway, and thus far some show no benefit while in others there is a definite advantage to the patients given the drug. These trials must be continued to their conclusion, but misonidazole must be regarded as the first of a series of radiosensitizers to reach the clinic for trial. There is a promise of more effective drugs becoming available within the next few years. Those showing a lower lipophilicity than misonidazole have been found to have a shorter half-life and a lower uptake in neural tissue in animal studies. One such drug, desmethylmisonidazole, is presently undergoing clinical trial

  9. Factor de crecimiento semejante a la insulina tipo I (IGF-I y cirrosis hepática Insulin-like growth factor I (IGF-I and liver cirrhosis

    Directory of Open Access Journals (Sweden)

    M. Conchillo

    2007-03-01

    Full Text Available El factor de crecimiento semejante a la insulina tipo I (IGF-I es una hormona polipeptídica segregada en múltiples tejidos por efecto de la hormona de crecimiento (GH. Es responsable de parte de las acciones de la GH y además tiene efecto hipoglucemiante y anabolizante. El 90% del IGF-I circulante es de origen hepático y ejerce efectos autocrinos, paracrinos y endocrinos, estos últimos en múltiples tejidos. En la cirrosis hepática se produce una disminución progresiva de la producción hepática de IGF-I que llega a ser indetectable en la enfermedad avanzada. Algunas de las complicaciones de la cirrosis, fundamentalmente nutricionales y metabólicas (resistencia a insulina, desnutrición, osteopenia, hipogonadismo, alteraciones intestinales podrían estar, al menos en parte, relacionadas con esta carencia de IGF-I dado que algunas acciones de IGF-I representan la imagen inversa de las complicaciones de la cirrosis. A pesar de ello, nunca se había propuesto tratamiento sustitutivo con IGF-I en la cirrosis. En una serie de estudios experimentales realizados en ratas cirróticas se demostró que el tratamiento con dosis bajas de IGF-I recombinante produce dos tipos de efectos en la cirrosis experimental: a mejoría del hígado, dado que mejora la función hepatocelular, la hipertensión portal y la fibrosis hepática; y b mejoría de las alteraciones extrahepáticas de la cirrosis dado que mejora la eficiencia del alimento ingerido, la masa muscular, la masa ósea, la función y estructura gonadales y la función y estructura intestinales con normalización de la malabsorción de azúcares y aminoácidos y la mejoría de la función intestinal de barrera manifestada por disminución de la endotoxemia y la translocación bacteriana. Posteriormente el primer ensayo clínico piloto, aleatorizado, doble ciego y controlado con placebo llevado a cabo en un número reducido de pacientes cirróticos demostró aumento de la albúmina sérica y

  10. DA Negatively Regulates IGF-I Actions Implicated in Cognitive Function via Interaction of PSD95 and nNOS in Minimal Hepatic Encephalopathy.

    Science.gov (United States)

    Ding, Saidan; Zhuge, Weishan; Wang, Xuebao; Yang, Jianjing; Lin, Yuanshao; Wang, Chengde; Hu, Jiangnan; Zhuge, Qichuan

    2017-01-01

    Insulin-like growth factor I (IGF-I) has been positively correlated with cognitive ability. Cognitive decline in minimal hepatic encephalopathy (MHE) was shown to be induced by elevated intracranial dopamine (DA). The beneficial effect of IGF-I signaling in MHE remains unknown. In this study, we found that IGF-I content was reduced in MHE rats and that IGF-I administration mitigated cognitive decline of MHE rats. A protective effect of IGF-I on the DA-induced interaction between postsynaptic density protein 95 (PSD95) and neuronal nitric oxide synthase (nNOS) was found in neurons. Ribosomal S6 protein kinase (RSK) phosphorylated nNOS in response to IGF-I by recruiting extracellular signal-regulated kinase (ERK1/2). In turn, DA inactivated the ERK1/2/RSK pathway and stimulated the PSD95-nNOS interaction by downregulating IGF-I. Inhibition of the interaction between PSD95 and nNOS ameliorated DA-induced memory impairment. As DA induced deficits in the ERK1/2/RSK pathway and the interaction between PSD95 and nNOS in MHE brains, IGF-I administration exerted a protective effect via interruption of the interaction between PSD95 and nNOS. These results suggest that IGF-I antagonizes DA-induced cognitive loss by disrupting PSD95-nNOS interactions in MHE.

  11. DA Negatively Regulates IGF-I Actions Implicated in Cognitive Function via Interaction of PSD95 and nNOS in Minimal Hepatic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Saidan Ding

    2017-09-01

    Full Text Available Insulin-like growth factor I (IGF-I has been positively correlated with cognitive ability. Cognitive decline in minimal hepatic encephalopathy (MHE was shown to be induced by elevated intracranial dopamine (DA. The beneficial effect of IGF-I signaling in MHE remains unknown. In this study, we found that IGF-I content was reduced in MHE rats and that IGF-I administration mitigated cognitive decline of MHE rats. A protective effect of IGF-I on the DA-induced interaction between postsynaptic density protein 95 (PSD95 and neuronal nitric oxide synthase (nNOS was found in neurons. Ribosomal S6 protein kinase (RSK phosphorylated nNOS in response to IGF-I by recruiting extracellular signal-regulated kinase (ERK1/2. In turn, DA inactivated the ERK1/2/RSK pathway and stimulated the PSD95–nNOS interaction by downregulating IGF-I. Inhibition of the interaction between PSD95 and nNOS ameliorated DA-induced memory impairment. As DA induced deficits in the ERK1/2/RSK pathway and the interaction between PSD95 and nNOS in MHE brains, IGF-I administration exerted a protective effect via interruption of the interaction between PSD95 and nNOS. These results suggest that IGF-I antagonizes DA-induced cognitive loss by disrupting PSD95–nNOS interactions in MHE.

  12. Development and biological function of the female gonads and genitalia in IGF-I deficiency -- Laron syndrome as a model.

    Science.gov (United States)

    Laron, Zvi

    2006-01-01

    Laron syndrome (LS) or primary GH insensitivity is a unique human model to study the effects of congenital IGF-I deficiency. Within our cohort of 63 patients with LS, 15 female patients were regularly followed since birth or infancy, throughout puberty. We observed that they were short at birth, with small genitalia and gonads -- during puberty, developed delayed puberty but eventually reached between 16 and 19 1/2 years full sexual development. Reproduction is unaffected at a young adult age. It is concluded that IGF-I in concert with the sex hormones has a modulatory but not essential function on female sexual development and maturation.

  13. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  14. Organ-Specific and Age-Dependent Expression of Insulin-like Growth Factor-I (IGF-I) mRNA Variants: IGF-IA and IB mRNAs in the Mouse

    OpenAIRE

    Ohtsuki, Takashi; Otsuki, Mariko; Murakami, Yousuke; Maekawa, Tetsuya; Yamamoto, Takashi; Akasaka, Koji; Takeuchi, Sakae; Takahashi, Sumio

    2005-01-01

    Insulin-like growth factor-I (IGF-I) gene generates several IGF-I mRNA variants by alternative splicing. Two promoters are present in mouse IGF-I gene. Each promoter encodes two IGF-I mRNA variants (IGF-IA and IGF-IB mRNAs). Variants differ by the presence (IGF-IB) or absence (IGF-IA) of a 52-bp insert in the E domain-coding region. Functional differences among IGF-I mRNAs, and regulatory mechanisms for alternative splicing of IGF-I mRNA are not yet known. We analyzed the expression of mouse ...

  15. Effect of oral alpha-tocopherol and zinc on plasma status, IGF-I levels, weight gain and immune response in young calves

    DEFF Research Database (Denmark)

    Sehested, J.; Jørgensen, C.; Mortensen, S.B.

    2004-01-01

    IGF-I levels generally increased from birth to week 8, but were not affected by Zn or vit. E. Daily weight gain was highest in the Zn group, but this was not related to an increased IGF-I level. The vit. E group responded earlier than the Zn and control groups to the tetanus vaccination....

  16. Changes in circulating level of IGF-I and IGF-binding protein-1 from the first to second trimester as predictors of preeclampsia

    DEFF Research Database (Denmark)

    Vatten, Lars J; Nilsen, Tom I L; Juul, Anders

    2008-01-01

    To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia.......To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia....

  17. The effect of epidermal growth factor and IGF-I infusion on hepatic and renal expression of the IGF-system in adult female rats

    NARCIS (Netherlands)

    J.W. van Neck (Han); E.M. Berghout; L. Vinter-Jensen; C.A.H. Groffen; V. Cingel-Ristic; N.F. Dits (Natasja); S.L.S. Drop (Stenvert); A. Flyvbjerg (Allan)

    2000-01-01

    textabstractSystemic administration of epidermal growth factor (EGF) in neonatal rats results in reduced body weight gain and decreased circulating levels of IGF-I, suggesting its involvement in EGF-induced growth retardation. We investigated the effect of EGF and/or IGF-I

  18. Effects of Moderate Aerobic Exercise Combined With Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy

    2002-01-01

    ... cancer, circulating estrogens and IGF-I. We will also test whether this type of diet/exercise program will produce significant reductions in the peripheral production of estrone by adipose tissue through its impact on the reduction of fat mass...

  19. Effects of dietary carbohydrate sources on plasma glucose, insulin and IGF-I levels in multiparous sows

    NARCIS (Netherlands)

    Wientjes, J.G.M.; Soede, N.M.; Aarsse, F.; Laurenssen, B.F.A.; Koopmanschap, R.E.; Brand, van den H.; Kemp, B.

    2012-01-01

    Effects of different carbohydrate sources on plasma glucose, insulin and insulin-like growth factor-I (IGF-I) levels were compared to subsequently be able to study effects of insulin-stimulating diets on follicle development in sows. The following feed components were tested in 12 sows during six

  20. Co-induction of hepatic IGF-I and progranulin mRNA by growth hormone in tilapia, Oreochromis mossambiccus

    Science.gov (United States)

    Like IGF-I, progranulin (pgrn) is a growth factor involved in tumorigenesis and wound healing. We report here the identification and characterization of pgrn cDNA in tilapia and the regulation of its expression by growth hormone(GH). The tilapia pgrn cDNA was cloned by RT-PCR ampliWcation, using g...

  1. Lower levels of circulating IGF-I in Type 1 diabetic women with frequent severe hypoglycaemia during pregnancy

    DEFF Research Database (Denmark)

    Ringholm Nielsen, L; Juul, A; Pedersen-Bjergaard, U

    2008-01-01

    Severe hypoglycaemia is a significant problem in pregnant women with Type 1 diabetes. We explored whether frequent severe hypoglycaemia during pregnancy in women with Type 1 diabetes is related to placental growth hormone (GH) and insulin-like growth factor I (IGF-I) levels....

  2. Maternal exposure to UV filters and associations to maternal thyroid hormones and IGF-I/IGFBP3 and birth outcomes

    DEFF Research Database (Denmark)

    Krause, Marianna; Frederiksen, Hanne; Sundberg, Karin

    2018-01-01

    as birth outcomes (weight, height, and head and abdominal circumferences) were examined. RESULTS: Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T3), thyroxine (T4), Insulin-like Growth Factor-I (IGF-I) and its binding protein IGFBP3, were observed in mothers...

  3. Systemic administration of insulin-like growth factor I (IGF-I) causes growth of the rat prostate

    DEFF Research Database (Denmark)

    Tørring, N; Vinter-Jensen, L; Pedersen, S B

    1997-01-01

    PURPOSE: To investigate the effects of insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) on the rat prostate. In addition, we investigated the effect of ornithine decarboxylase (ODC) inhibition with alpha-diflouromethylornitine (DFMO) on the expected growth of the prostate.MA...

  4. Determining the normal range for IGF-I, IGFBP-3, and ALS: new reference data based on current internal standards.

    Science.gov (United States)

    Ertl, Diana-Alexandra; Gleiss, Andreas; Sagmeister, Susanne; Haeusler, Gabriele

    2014-09-01

    The measurement of insulin-like growth factors (IGF-I) and insulin-like growth factor-binding protein (IGFBP-3) often serves as first-line testing in children with growth disorders. The role of acid-labile subunit (ALS) as a screening parameter for homozygous or heterozygous mutations of the ALS gene still has to be determined. IGF-I, IGFBP-3, and ALS were measured in 252 samples from children and adolescents. Reference curves were fitted using generalized additive model for location, scale and shape (GAMLSS) models and SD-Scores were calculated. Bootstrap analysis was used to quantify the uncertainty of the estimated percentiles. Bland-Altman plots were used to investigate the discrepancy between our newly estimated standard deviation scores (SDS) and SDS calculated on the basis of previous reference data. We present reference data for enzyme-linked immunosorbent assay (ELISA) measurements based on recommended internal standard for IGF-I, IGFBP-3, and ALS suitable for calculation of SD-scores. The Bland-Altman plot shows a rough agreement between the previous SDS calculation and our new one only for SDS around 1; for SDS at -2, an average difference of 0.83 SD was noticed. Our IGF-I reference values for the interval of interest in diagnosing growth hormone deficiency (GHD) (prepubertal age) are solid as proved by bootstrap analysis. The difference in calculated SD scores by using data provided previously highlights the importance of using labor and method specific reference data.

  5. Administration route-dependent effects of estrogens on IGF-I levels during fixed GH replacement in women with hypopituitarism

    NARCIS (Netherlands)

    van der Klaauw, Agatha A.; Biermasz, Nienke R.; Zelissen, Pierre M. J.; Pereira, Alberto M.; Lentjes, Eef G. W. M.; Smit, Johannes W. A.; van Thiel, Sjoerd W.; Romijn, Johannes A.; Roelfsema, Ferdinand

    2007-01-01

    GH-deficient women using oral estradiol treatment require higher doses of recombinant human GH (rhGH) to achieve similar IGF-I levels when compared with men and women on transdermal estradiol replacement. The aim of this study was to evaluate the effects of oral versus transdermal estrogen

  6. Local administration of insulin-like growth factor-I (IGF-I) stimulates tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Hansen, Mette; Boesen, Anders; Holm, Lars

    2013-01-01

    Collagen is the predominant structural protein in tendons and ligaments, and can be controlled by hormonal changes. In animals, injections of insulin-like growth factor I (IGF-I) has been shown to increase collagen synthesis in tendons and ligaments and to improve structural tissue healing, but t...

  7. [Differential expression of IGF-I and its mRNA in mandibular condylar cartilage of rat--direct evidence for servosystem theory of facial growth].

    Science.gov (United States)

    Zhou, Z; Luo, S

    1998-05-01

    It was studied the expression of IGF-I and its mRNA in the condylar cartilage of 10 7-week-old SD male rats by using in situ hybridization and immunohisto-chemistry technique. The results showed both IGF-I and its gene expressed in growing rat condyle. IGF-I peptide was abundant in germinal zone, and positive reaction of its mRNA was strongest in transitional and maturational zones. These indicate that condylar cartilage has the capability of local production and secretion of IGF-I, mediating the command effect of STH, and differential expression of IGF-I and its mRNA might establish the local feedback loop, which supply a direct evidence for servosystem theory of facial growth.

  8. Study on the relationship between serum TNF-α, IGF-I levels and lipid peroxidation in patients with fatty liver

    International Nuclear Information System (INIS)

    Li Yuqiang; Niu Guoping

    2006-01-01

    Objective: To assess the relationship between serum TNF-α, IGF-I levels and lipid peroxidation in patients with fatty liver. Methods: Serum TNF-α, IGF-I (with RIA) levels were examined in 44 patients with fatty liver and 30 controls. Ser- um levels of malondialdehyde (MDA), superoxidase (SOD) were measured with chemocolorimetry in these subjects. Results: Serum levels of TNF-α, IGF-I were significantly higher in patients with fatty liver than those in controls P<0.01 ), while the serum levels of MDA, SOD were significantly lower (P<0.01). Serum levels of IGF-I were negatively correlated with MDA levels ( r -0. 4132, P<0.05), TNF-α levels were positive correlated with MDA levels (r=0.4318, P<0.05). Conclusion: Lipid peroxidation was present in patients with fatty liver, with correlated changes of TNF-α and IGF-I levels. (authors)

  9. Clinical significance of measurement of changes of plasma NPY, CGRP and serum IGF-I levels in patients with acute cerebral infarction

    International Nuclear Information System (INIS)

    Deng Weiqun; Zhao Yushan

    2007-01-01

    Objective: To investigate the clinical significance of changes of plasma NPY, CGRP and serum IGF-I levels in patients with acute cerebral infarction. Methods: Plasma NPY, CGRP and serum IGF-I levels were determined with RIA in 32 patients with acute cerebral infarction both before and after treatment and 30 controls. Results: Before treatment plasma NPY levels were significantly higher (P<0.01) than those in the controls, while plasma CGRP and serum IGF-I levels were lower than those in controls (P<0.01). After treatment, plasma NPY levels decreased significantly (vs before treatment P<0.05), and plasma CGRP and serum IGF-I levels increased (P<0.05). Conclusion: Changes of plasma NPY, CGRP and serum IGF-I levels were closely related to the disease process in patients with acute cerebral infarction, determination of which was of important clinical values. (authors)

  10. Serum insulin-like growth factor I (IGF-I) and IGF-binding protein 3 levels are increased in central precocious puberty

    DEFF Research Database (Denmark)

    Juul, A; Scheike, Thomas Harder; Nielsen, C T

    1995-01-01

    between IGF-I and IGFBP-3 (i.e. free biologically active IGF-I) declined concomitantly with a decrease in growth velocity. Serum levels of IGF-I and IGFBP-3 (expressed as the SD score for bone age), but not those of estradiol, correlated with height velocity before and during treatment (r = 0.34; P ...Central precocious puberty (CPP) is characterized by early activation of the pituitary-gonadal axis, which leads to increased growth velocity and development of secondary sexual characteristics. It is generally believed that gonadal sex steroids stimulate pulsatile GH secretion, which, in turn......, stimulates insulin-like growth factor I (IGF-I) and IGF-binding protein 3 (IGFBP-3) production. However, little is known about GH, IGF-I, and IGFBP-3 serum levels in children with precocious puberty. Treatment of CPP by GnRH agonists has become the treatment of choice. However, the effect of long term...

  11. Mecasermin rinfabate: insulin-like growth factor-I/insulin-like growth factor binding protein-3, mecaserimin rinfibate, rhIGF-I/rhIGFBP-3.

    Science.gov (United States)

    2005-01-01

    -daily injections of rhIGF-I. The full results from the pivotal trial are expected in 2005. In April 2003 Insmed initiated a named patient programme in Europe that will make available mecasermin rinfabate for the treatment of GHIS-Laron syndrome. The treatment of patients was initiated in Scandinavia, with authorisation pending in several other European countries. Mecasermin rinfabate will be made available to those GHIS patients who, in the opinion of their doctor, may benefit from IGF-I therapy. At precommercial scale quantities, the drug will be available on a limited basis.A phase II dose-ranging study in children with GHIS was completed at Saint Bartholomew's and the Royal London School of Medicine, London, UK. A single dose of mecasermin rinfabate delivered the same amount of IGF-1 as two daily injections of unbound IGF-1. No adverse events were reported. Insmed has acquired an exclusive licence to Pharmacia's regulatory filings concerning yeast-derived insulin-like growth factor 1 (IGF-1). These filings were used by Pharmacia to receive marketing approvals in several European countries and also in the IND application with the US FDA. Insmed believes that this licence will facilitate the development of mecasermin rinfabate for the treatment of children with GHIS. In January 2003, Insmed announced positive results from a double-blind, placebo-controlled, dose-ranging study of mecasermin rinfabate in adolescent patients with type 1 diabetes receiving insulin therapy. The study was conducted at the University of Cambridge, Cambridge, UK, under supervision of Prof. D. Dunger. The researchers from The Robarts Research Institute and the University of Western Ontario, Canada (leading investigator T.L. Delovitch, the Sheldon H. Weinstein scientist in Diabetes at the University of Western Ontario) have found that mecasermin rinfabate complex was significantly more effective than IGF-1 in reducing the severity of insulitis, beta cell destruction and delaying the onset of type 1

  12. Distribution and levels of [125I]IGF-I, [125I]IGF-II and [125I]insulin receptor binding sites in the hippocampus of aged memory-unimpaired and -impaired rats

    International Nuclear Information System (INIS)

    Quirion, R.; Rowe, W.; Kar, S.; Dore, S.

    1997-01-01

    The insulin-like growth factors (IGF-I and IGF-II) and insulin are localized within distinct brain regions and their respective functions are mediated by specific membrane receptors. High densities of binding sites for these growth factors are discretely and differentially distributed throughout the brain, with prominent levels localized to the hippocampal formation. IGFs and insulin, in addition to their growth promoting actions, are considered to play important roles in the development and maintenance of normal cell functions throughout life. We compared the anatomical distribution and levels of IGF and insulin receptors in young (five month) and aged (25 month) memory-impaired and memory-unimpaired male Long-Evans rats as determined in the Morris water maze task in order to determine if alterations in IGF and insulin activity may be related to the emergence of cognitive deficits in the aged memory-impaired rat. In the hippocampus, [ 125 I]IGF-I receptors are concentrated primarily in the dentate gyrus (DG) and the CA3 sub-field while high amounts of [ 125 I]IGF-II binding sites are localized to the pyramidal cell layer, and the granular cell layer of the DG. [ 125 I]insulin binding sites are mostly found in the molecular layer of the DG and the CA1 sub-field. No significant differences were found in [ 125 I]IGF-I, [ 125 I]IGF-II or [ 125 I]insulin binding levels in any regions or laminae of the hippocampus of young vs aged rats, and deficits in cognitive performance did not relate to altered levels of these receptors in aged memory-impaired vs aged memory-unimpaired rats. Other regions, including various cortical areas, were also examined and failed to reveal any significant differences between the three groups studied.It thus appears that IGF-I, IGF-II and insulin receptor sites are not markedly altered during the normal ageing process in the Long-Evans rat, in spite of significant learning deficits in a sub-group (memory-impaired) of aged animals. Hence

  13. Clonage de l'IGF-I et de son récepteur chez le turbot (Psetta maxima

    Directory of Open Access Journals (Sweden)

    ELIES G.

    1998-07-01

    Full Text Available Les IGF, leurs récepteurs et leurs protéines de liaison constituent une famille moléculaire qui joue un rôle essentiel dans la régulation de la croissance et du développement. Nous nous sommes intéressés à la caractérisation moléculaire de l'IGF-l et de son récepteur (IGF-1R chez le turbot (Psetta maxima, un poisson plat téléostéen. Par RT-PCR, nous avons clone un ADNc codant pour les quatre domaines de l'IGF-l mature. La protéine présente 70 à 96 % d'identité avec les autres IGF-I de vertébrés. Le clonage de la séquence codante entière du récepteur a nécessité la construction d'une banque d'ADNc d'embryons de turbots. Le récepteur est organisé en domaines dont la taille et les caractéristiques sont semblables à celles des autres récepteurs aux IGF de type 1 décrits chez les mammifères et le poulet. La région catalytique est particulièrement conservée. Dans certains domaines, notamment dans la région C-terminale du précurseur, quelques différences qui pourraient avoir une importance fonctionnelle sont cependant observées. Enfin, par RT-PCR, nous avons mis en évidence une régulation ontogénique du statut de polyadénylation des ARNm IGF-1R.

  14. Effects of Growth Hormone/IGF-I and Exercise on Unloaded Bones

    Science.gov (United States)

    Harper, J. S.; Arnaud, S. B.; Gosselink, K. L.; Grindeland, R. E.

    1994-01-01

    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) in combination with exercise prevent muscle atrophy induced by unloading in the tail-suspension rat model for space flight (Gosselink et al, FASEB J 1994). This study evaluated the effects of these treatments on bone. Hypophysectomized rats were suspended (S) and treated with 1mg/kg/day CH plus IGF-I (H) or vehicle (Sal) daily by injection and exercised (Ex) by 3 climbs up a 1m ladder carrying a load equal to 30% the initial body weight (BW) 3x/day for 10 days. Tibial epiphysis (Epi) widths were measured by micrometry and femoral Bone Mineral Content (fBMC) in excised femurs by DEXA (Lunar DPX-L). Serum calcium (Ca) and phosphorus (Pi) were measured by COBAS Autoanalyzer (Roche Diag.). Ambulatory (Amb)-H treated rats showed growth rates of 6.6+-0.9 g/day, similar to S-H-Ex and higher than S-H (3.210.6, p less than 0.05) and S-Sal (-0.711.0, p less than 0.05). Epi widths were 10% lower in S-Sal, and S-Sal-Ex, and increased 100% in all H groups. fBMC was less in S than Amb, only when all S groups are compared to both Amb groups (p less than 0.03). H treatment increased fBMC (p less than 0.05) but reduced fBMC/100g BW in all H groups (p less than 0.001). The reduced density of H bone cannot be attributed to low circulating Ca. and Pi since they were higher in H than Sal (p less than 0.001). H treatment for 10 days in doses sufficient to support normal growth in BW failed to produce normal Epi widths or fBMC, even when combined with exercise. The suspension effect observed in Epi widths was not corrected by H or Ex alone, but was improved by H plus a This regimen. although effective in preventing muscle atrophy, failed to return bone measures, Epi widths and fBMC, to normal.

  15. Changes of Cerebral and/or Peripheral Adenosine A₁ Receptor and IGF-I Concentrations under Extended Sleep Duration in Rats.

    Science.gov (United States)

    Chennaoui, Mounir; Arnal, Pierrick J; Dorey, Rodolphe; Sauvet, Fabien; Ciret, Sylvain; Gallopin, Thierry; Leger, Damien; Drogou, Catherine; Gomez-Merino, Danielle

    2017-11-17

    Extended sleep improves sustained attention and reduces sleep pressure in humans. Downregulation of adenosine A₁ receptor (A₁R) and modulation of the neurotrophic factor insulin growth factor-1 (IGF-I) in brain structures controlling attentional capacities could be involved. In the frontal cortex and hippocampus of rats, we measured adenosine A₁R and IGF-I protein concentrations after photoperiod-induced sleep extension. Two groups of twelve rats were adapted over 14 days to a habitual (CON) 12:12 light-dark (LD) schedule and an extended (EXT) 16:8 LD schedule. IGF-I content was also measured in plasma, liver, and skeletal muscle. In EXT, compared to CON rats, A₁R content in the frontal cortex was significantly lower ( p IGF-I content was higher ( p IGF-I content in plasma and muscle was higher ( p IGF-I levels. This photoperiod induced an anabolic profile with increased weight gain and circulating and muscular IGF-I levels. An extension of sleep duration might favor cerebral and peripheral anabolism, which may help attentional and physical capacities.

  16. Free and total insulin-like growth factor I (IGF-I), IGF-binding protein-1 (IGFBP-1), and IGFBP-3 and their relationships to the presence of diabetic retinopathy and glomerular hyperfiltration in insulin-dependent diabetes mellitus

    NARCIS (Netherlands)

    J.A.M.J.L. Janssen (Joseph); M.L. Jacobs (Marloes); F.H.M. Derkx (Frans); R.F.A. Weber (Rob); A-J. van der Lely (Aart-Jan); S.W.J. Lamberts (Steven)

    1997-01-01

    textabstractThe existing literature on serum insulin-like growth factor I (IGF-I) levels in insulin-dependent diabetes mellitus (IDDM) is conflicting. Free IGF-I may have greater physiological and clinical relevance than total IGF- I. Recently, a validated method has been developed to measure free

  17. Free and total insulin-like growth factor I (IGF-I), IGF-binding protein-1 (IGFBP-1), and IGFBP-3 and their relationships to the presence of diabetic retinopathy and glomerular hyperfiltration in insulin-dependent diabetes mellitus

    NARCIS (Netherlands)

    J.A.M.J.L. Janssen (Joseph); M.L. Jacobs (Marloes); F.H.M. Derkx (Frans); R.F.A. Weber (Robert); A-J. van der Lely (Aart-Jan); S.W.J. Lamberts (Steven)

    1997-01-01

    textabstractThe existing literature on serum insulin-like growth factor I (IGF-I) levels in insulin-dependent diabetes mellitus (IDDM) is conflicting. Free IGF-I may have greater physiological and clinical relevance than total IGF-I. Recently, a validated method has

  18. Leptin does not mediate short-term fasting-induced changes in growth hormone pulsatility but increases IGF-I in leptin deficiency states.

    Science.gov (United States)

    Chan, Jean L; Williams, Catherine J; Raciti, Patricia; Blakeman, Jennifer; Kelesidis, Theodore; Kelesidis, Iosif; Johnson, Michael L; Thorner, Michael O; Mantzoros, Christos S

    2008-07-01

    States of acute and chronic energy deficit are characterized by increased GH secretion and decreased IGF-I levels. The objective of the study was to determine whether changes in levels of leptin, a key mediator of the adaptation to starvation, regulate the GH-IGF system during energy deficit. We studied 14 healthy normal-weight men and women during three conditions: baseline fed and 72-h fasting (to induce hypoleptinemia) with administration of placebo or recombinant methionyl human leptin (r-metHuLeptin) (to reverse the fasting associated hypoleptinemia). We also studied eight normal-weight women with exercise-induced chronic energy deficit and hypothalamic amenorrhea at baseline and during 2-3 months of r-metHuLeptin treatment. GH pulsatility, IGF levels, IGF and GH binding protein (GHBP) levels were measured. During short-term energy deficit, measures of GH pulsatility and disorderliness and levels of IGF binding protein (IGFBP)-1 increased, whereas leptin, insulin, IGF-I (total and free), IGFBP-4, IGFBP-6, and GHBP decreased; r-metHuLeptin administration blunted the starvation-associated decrease of IGF-I. In chronic energy deficit, total and free IGF-I, IGFBP-6, and GHBP levels were lower, compared with euleptinemic controls; r-metHuLeptin administration had no major effect on GH pulsatility after 2 wk but increased total IGF-I levels and tended to increase free IGF-I and IGFBP-3 after 1 month. The GH/IGF system changes associated with energy deficit are largely independent of leptin deficiency. During acute energy deficit, r-metHuLeptin administration in replacement doses blunts the starvation-induced decrease of IGF-I, but during chronic energy deficit, r-metHuLeptin administration increases IGF-I and tends to increase free IGF-I and IGFBP-3.

  19. Genomewide meta-analysis identifies loci associated with IGF-I and IGFBP-3 levels with impact on age-related traits

    DEFF Research Database (Denmark)

    Teumer, Alexander; Qi, Qibin; Nethander, Maria

    2016-01-01

    The growth hormone/insulin-like growth factor (IGF) axis can be manipulated in animal models to promote longevity, and IGF-related proteins including IGF-I and IGF-binding protein-3 (IGFBP-3) have also been implicated in risk of human diseases including cardiovascular diseases, diabetes, and cancer......-associated variant rs2153960 (FOXO3) was observed to be a genomewide significant SNP for IGF-I concentrations. Bioinformatics analysis suggested enrichment of putative regulatory elements among these IGF-I- and IGFBP-3-associated loci, particularly of rs646776 at CELSR2. In conclusion, this study identified several...

  20. Circadian variation in serum free and total insulin-like growth factor (IGF)-I and IGF-II in untreated and treated acromegaly and growth hormone deficiency

    DEFF Research Database (Denmark)

    Skjaerbaek, Christian; Frystyk, Jan; Kaal, Andreas

    2000-01-01

    to the nocturnal increase in IGF binding protein-1. In this study we have investigated the circadian variation in circulating free IGF-I and IGF-II in patients with acromegaly and patients with adult onset growth hormone deficiency. PATIENTS: Seven acromegalic patients were studied with and without treatment...... no significant circadian variations in free IGF-I or free IGF-II in either of the two occasions. In contrast, there was a significant circadian variation of total IGF-I after adjustment for changes in plasma volume in both treated and untreated acromegaly and GH deficiency in all cases with a peak between 0300 h...

  1. CARTILAGE CONSTRUCTS ENGINEERED FROM CHONDROCYTES OVEREXPRESSING IGF-I IMPROVE THE REPAIR OF OSTEOCHONDRAL DEFECTS IN A RABBIT MODEL

    Science.gov (United States)

    Madry, Henning; Kaul, Gunter; Zurakowski, David; Vunjak-Novakovic, Gordana; Cucchiarini, Magali

    2015-01-01

    Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes over expressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-over expressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects. PMID:23588785

  2. Cartilage constructs engineered from chondrocytes overexpressing IGF-I improve the repair of osteochondral defects in a rabbit model

    Directory of Open Access Journals (Sweden)

    H Madry

    2013-04-01

    Full Text Available Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes overexpressing a human insulin-like growth factor I (IGF-I gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-overexpressing chondrocytes markedly improved osteochondral repair compared with control (lacZ constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects.

  3. Peripheral blood aspirates overexpressing IGF-I via rAAV gene transfer undergo enhanced chondrogenic differentiation processes.

    Science.gov (United States)

    Frisch, Janina; Orth, Patrick; Rey-Rico, Ana; Venkatesan, Jagadeesh Kumar; Schmitt, Gertrud; Madry, Henning; Kohn, Dieter; Cucchiarini, Magali

    2017-11-01

    Implantation of peripheral blood aspirates induced towards chondrogenic differentiation upon genetic modification in sites of articular cartilage injury may represent a powerful strategy to enhance cartilage repair. Such a single-step approach may be less invasive than procedures based on the use of isolated or concentrated MSCs, simplifying translational protocols in patients. In this study, we provide evidence showing the feasibility of overexpressing the mitogenic and pro-anabolic insulin-like growth factor I (IGF-I) in human peripheral blood aspirates via rAAV-mediated gene transfer, leading to enhanced proliferative and chondrogenic differentiation (proteoglycans, type-II collagen, SOX9) activities in the samples relative to control (reporter rAAV-lacZ) treatment over extended periods of time (at least 21 days, the longest time-point evaluated). Interestingly, IGF-I gene transfer also triggered hypertrophic, osteo- and adipogenic differentiation processes in the aspirates, suggesting that careful regulation of IGF-I expression may be necessary to contain these events in vivo. Still, the current results demonstrate the potential of targeting human peripheral blood aspirates via therapeutic rAAV transduction as a novel, convenient tool to treat articular cartilage injuries. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  4. Indications, limitations and pitfalls in the determination of human growth hormone, IGF-I and their binding proteins.

    Science.gov (United States)

    Laron, Zvi; Bidlingmaier, Martin; Strasburger, Christian Joseph

    2007-10-01

    Deviations from normal growth are a major part of Pediatric Endocrinology. The principal post-natal growth promoting hormones are pituitary growth hormone (GH) and insulin-like growth factor-I (IGF-I). The GH-IGF-I axis has many links and portals, the secrets of which have been disclosed in recent years by scientific advances (genetic and biochemical technologies). In this article, we describe the players in the GH axis, the auxological indications for performing GH evaluation tests, enumerate the most frequently used tests and discuss the laboratory tests which help to define the pathological entities along the GH axis. Emphasis is put on the limitations of methods used, lack of standards, norms and the possible errors in diagnosis and treatment indications that may evolve. As both hGH and IGF-I immunoassay measurements represent cornerstones in the diagnosis and monitoring of the different etiological entities presenting with short stature, clinicians must have an insight into the variability and limitations of these analytical techniques. Interpretation of biochemical results without proper reference data and without knowledge of the assay-inherent characteristics inevitably leads to misdiagnosis, unnecessary further testing and treatment and imposes a burden on the child, family and the health care system.

  5. The ratio between serum levels of insulin-like growth factor (IGF)-I and the IGF binding proteins (IGFBP-1, 2 and 3) decreases with age in healthy adults and is increased in acromegalic patients

    DEFF Research Database (Denmark)

    Juul, A; Main, K; Blum, W F

    1994-01-01

    Several in-vitro studies have suggested that the biological actions of IGF-I can be modified by the presence of specific IGF binding proteins. In man, the 24-hour serum levels of IGF-I and IGFBP-3 remain constant, but short-term changes in the IGF-I/IGFBP-3 ratio have been described following GH...... administration. Serum levels of IGF-I and IGFBP-3 decrease with age in normal adults and are elevated in active acromegaly due to excessive GH secretion. However, the individual ratios between serum levels of IGF-I and IGFBP-3 in acromegalic and healthy adults have not been described previously....

  6. Differential basal and exercise-induced IGF-I system responses to resistance vs. calisthenic-based military readiness training programs.

    Science.gov (United States)

    Nindl, Bradley C; Alemany, Joseph A; Rarick, Kevin R; Eagle, Shawn R; Darnell, Mathew E; Allison, Katelyn F; Harman, Everett A

    2017-02-01

    The purpose of this study was to: 1) evaluate differential responses of the IGF-I system to either a calisthenic- or resistance exercise-based program and 2) determine if this chronic training altered the IGF-I system during an acute resistance exercise protocol. Thirty-two volunteers were randomly assigned into a resistance exercise-based training (RT) group (n=15, 27±5y, 174±6cm, 81±12kg) or a calisthenic-based training group (CT) (n=17, 29±5y, 179±8cm, 85±10kg) and all underwent 8weeks of exercise training (1.5h/d, 5d/wk). Basal blood was sampled pre- (Week 0), mid- (Week 4) and post-training (Week 8) and assayed for IGF-I system analytes. An acute resistance exercise protocol (AREP) was conducted preand post-training consisting of 6 sets of 10 repetitions in the squat with two minutes of rest in between sets and the IGF-I system analytes measured. A repeated measures ANOVA (p≤0.05) was used for statistical analysis. No interaction or within-subject effects were observed for basal total IGF-I, free IGF-I, or IGFBP-1. IGFBP-2 (pre; 578.6±295.7post-training; 14.3±1.9μg/mL; p=0.01). An interaction was observed for the RT group as IGFBP-3 increased from pre to mid (3462.4±216.4 vs. 3962.2±227.9ng/mL), but was not significant at the post-training time point (3770.3±228.7ng/mL). AREP caused all analytes except free IGF-I (40% decrease) to increase (17-27%; p=0.001) during exercise, returning to baseline concentration into recovery. Post-training, bioavailable IGF-I recovered more rapidly post-exercise. 8wks of chronic physical training resulted in increased basal IGFBP-2 and IGFBP-3, decreased ALS, increased pre-AREP free IGF-I and a more rapid free IGF-I recovery post-AREP. While total IGF-I was insensitive to chronic physical training, changes were observed with circulating IGFBPs and bioavailable IGF-I. To glean the most robust information on the effects of exercise training, studies must move beyond relying solely on total IGF-I measures and should

  7. Development and clinical evaluation of a novel immunoassay for the binary complex of IGF-I and IGF-binding protein-1 in human serum

    DEFF Research Database (Denmark)

    Frystyk, Jan; Højlund, Kurt; Rasmussen, Kirsten Nyborg

    2002-01-01

    Correlation studies have suggested that IGF-binding protein (IGFBP)-1 is a dynamic regulator of free IGF-I. To further study this, we developed a monoclonal immunofluorometric assay specific for the binary complex of IGF-I and IGFBP-1 in human serum. An IGFBP-1 antibody, which recognizes all...... phospho-forms of IGFBP-1, was used for coating. An europium-labeled IGF-I antibody served as tracer. Assay incubation was performed at conditions approaching those in vivo (i.e. pH 7.4, 37 C). The assay was highly specific: no signal was obtained unless both IGF-I and IGFBP-1 were present and neither...

  8. Clinical significance of determination of serum IGF-I, TNF-α and SS levels in patients with chronic viral hepatitis

    International Nuclear Information System (INIS)

    Zhu Peiming

    2009-01-01

    Objective: To study the clinical significance of changes of serum IGF-I, TNF-α and somatostatin(SS) levels in patients with chronic viral hepatitis. Methods: Serum IGF-I, TNF-α and SS levels were determined with RIA in 30 patients with chronic viral hepatitis (B hepatitis, n=24,C hepatitis, n=6) and 30 controls.Results The serum IGF-I, TNF-α and SS levels in the patients were all significantly higher than those in controls (P<0.01). Conclusion: Serum IGF-I, TNF-α and SS levels were markedly increased in patients with chronic viral hepatitis, the exact mechanism and consequence of the changes required further study. (authors)

  9. Changes in circulating level of IGF-I and IGF-binding protein-1 from the first to second trimester as predictors of preeclampsia

    DEFF Research Database (Denmark)

    Vatten, Lars J; Nilsen, Tom I L; Juul, Anders

    2008-01-01

    OBJECTIVE: To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia. METHODS: Nested case-control study within a cohort of 29 948 pregnant women. Cases were women, who later...... developed preeclampsia, and controls were randomly selected women, who did not develop preeclampsia. IGF-I and IGFBP-1 were measured with ELISA in maternal blood samples that were collected in the first and second trimesters. We assessed associations of IGF-I and IGFBP-1 concentrations with later...... development of preterm (before the 37th week of gestation) and term preeclampsia. RESULTS: An increase in IGF-I from the first to second trimester was associated with higher risk of preterm preeclampsia; the odds ratio (OR) for the highest compared with lowest quartile of increase was 4.9 (95% confidence...

  10. Breast Cancer Risk in Relation to Serum IGF-I, IGFBP-3 and their Genetic Determinants: A Study Within the European Prospective Investigation into Cancer (EPIC)

    National Research Council Canada - National Science Library

    Kaaks, Rudolf

    2002-01-01

    Purpose and scope: we are conducting a large case-control study, nested within a prospective cohort, to estimate relative risks of breast cancer by levels of IGF-I and IGFBP-3, and to examine associations of IGF...

  11. Pregnancy-induced increase in circulating IGF-I is associated with progression of diabetic retinopathy in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Vestgaard, Marianne; Laugesen, Caroline S

    2011-01-01

    To evaluate the influence of Insulin-like Growth factor-I (IGF-I) and Placental Growth Hormone (GH) on progression of diabetic retinopathy during pregnancy in women with type 1 diabetes.......To evaluate the influence of Insulin-like Growth factor-I (IGF-I) and Placental Growth Hormone (GH) on progression of diabetic retinopathy during pregnancy in women with type 1 diabetes....

  12. Low serum insulin-like growth factor-I (IGF-I) level is associated with increased risk of vascular dementia.

    Science.gov (United States)

    Quinlan, Patrick; Horvath, Alexandra; Nordlund, Arto; Wallin, Anders; Svensson, Johan

    2017-12-01

    Insulin-like growth factor-I (IGF-I) is important for the adult brain, but little is known of the role of IGF-I in Alzheimeŕs disease (AD) or vascular dementia (VaD). A prospective study of 342 patients with subjective or objective mild cognitive impairment recruited at a single memory clinic. We determined whether serum IGF-I concentrations at baseline were associated with the risk of all-cause dementia, AD, or VaD. Patients developing mixed forms of AD and VaD were defined as suffering from VaD. The statistical analyses included Cox proportional hazards regression analysis. During the follow-up (mean 3.6 years), 95 (28%) of the patients developed all-cause dementia [AD, n=37 (11%) and VaD, n=42 (12%)]. Low as well as high serum IGF-I (quartile 1 or 4 vs. quartiles 2-3) did not associate with all-cause dementia [crude hazard ratio (HR) 1.30, 95% confidence interval (CI): 0.81-2.08 and crude HR 1.05, 95% CI: 0.63-1.75, respectively] or AD (crude HR 0.79, 95% CI: 0.35-1.79 and crude HR 0.94, 95% CI: 0.43-2.06, respectively]. In contrast, low serum IGF-I concentrations were associated with increased risk of VaD (quartile 1 vs. quartiles 2-3, crude HR 2.22, 95% CI: 1.13-4.36). The latter association remained significant also after adjustment for multiple covariates. In a memory clinic population, low serum IGF-I was a risk marker for subsequent VaD whereas low IGF-I did not associate with the risk of AD. High serum IGF-I was not related to the risk of conversion to dementia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Obesity alters gene expression for GH/IGF-I axis in mouse mammary fat pads: differential role of cortistatin and somatostatin.

    Directory of Open Access Journals (Sweden)

    Alicia Villa-Osaba

    Full Text Available Locally produced growth hormone (GH and IGF-I are key factors in the regulation of mammary gland (MG development and may be important in breast cancer development/progression. Somatostatin (SST and cortistatin (CORT regulate GH/IGF-I axis at various levels, but their role in regulating GH/IGF-I in MGs remains unknown. Since obesity alters the expression of these systems in different tissues and is associated to MG (patho physiology, we sought to investigate the role of SST/CORT in regulating GH/IGF-I system in the MGs of lean and obese mice. Therefore, we analyzed GH/IGF-I as well as SST/CORT and ghrelin systems expression in the mammary fat pads (MFPs of SST- or CORT-knockout (KO mice and their respective littermate-controls fed a low-fat (LF or a high-fat (HF diet for 16 wks. Our results demonstrate that the majority of the components of GH/IGF-I, SST/CORT and ghrelin systems are locally expressed in mouse MFP. Expression of elements of the GH/IGF-I axis was significantly increased in MFPs of HF-fed control mice while lack of endogenous SST partially suppressed, and lack of CORT completely blunted, the up-regulation observed in obese WT-controls. Since SST/CORT are known to exert an inhibitory role on the GH/IGFI axis, the increase in SST/CORT-receptor sst2 expression in MFPs of HF-fed CORT- and SST-KOs together with an elevation on circulating SST in CORT-KOs could explain the differences observed. These results offer new information on the factors (GH/IGF-I axis involved in the endocrine/metabolic dysregulation of MFPs in obesity, and suggest that CORT is not a mere SST sibling in regulating MG physiology.

  14. Identification of binding sites for an insulin-like growth factor (IGF-I) in the median eminence of the rat brain by quantitative autoradiography

    International Nuclear Information System (INIS)

    Bohannon, N.J.; Figlewicz, D.P.; Corp, E.S.; Wilcox, B.J.; Porte, D. Jr.; Baskin, D.G.

    1986-01-01

    The microanatomical location of IGF-I binding in the rat brain was determined by in vitro autoradiography with slide-mounted sections of frozen brain. Sections incubated in 0.1 nM [ 125 I]-iodo-IGF-I produced a dense grain concentration in regions of the autoradiographic image corresponding to the external palisade zone of the median eminence; other hypothalamic regions were not so heavily labeled. This reaction was significantly reduced in the presence of 100 nM IGF-I. Measurement of binding by computer digital image analysis of autoradiographic images showed that specific binding for IGF-I in the median eminence was 41.3 +/- 8 X 10(-3) fmol/mm2 (mean +/- SEM); nonspecific binding was 11.9 +/- 1.8 X 10(-3) fmol/mm2. In contrast, specific binding to other hypothalamic regions was uniformly lower. In a separate experiment, 1000 nM unlabeled insulin was added. Without insulin, specific binding was 23 +/- 0.9 X 10(-3) fmol/mm2; nonspecific binding was 8 +/- 0.5 X 10(-3) fmol/mm2. In the presence of 1000 nM unlabeled insulin, specific binding for [ 125 I]-iodo-IGF-I was 23 +/- 1 X 10(-3) fmol/mm2. The results suggest that a high concentration of receptors for an IGF-I-like molecule is present in the median eminence

  15. Significance of determination of female sex hormones (E2, LH, FSH), insulin-like growth factor I (IGF-I) and leptin in girls with precocious puberty

    International Nuclear Information System (INIS)

    Huang Jianrong

    2004-01-01

    Objective: To investigate the diagnostic value of determination of serum levels of estradiol (E 2 ), luteinizing hormone (LH) and follicle stimulating hormone (FSH), insulin-like growth factor (IGF-I) and leptin in girls with idiopathic central precocious puberty (ICPP). Methods: Serum E 2 , LH, FSH, IGF-I (with chemiluminescence immunoassay) and leptin (with RIA) levels were determined in 35 girls with early development of breast as the sign of precocious puberty, of which, 15 was considered to be of the ICPP group and 20 of simple premature thelarche group (SPT). Criteria of diagnosis for ICPP were: peak LH value>12IU/L and LH/FSH>1 after GnRH stimulating test. Results: Serum E 2 , LH, FSH, IGF-I leptin levels in girls with ICPP were significantly higher than those in the girls with SPT (P 0.2 as the cut-off value for diagnosis of ICPP there would still be a positive rate of 86.6% suggesting that the diagnostic criteria might be set lower. Serum IGF-I levels were positively correlated to those of E 2 (r=0.47, P 2 and IGF-I. Conclusion: Determinations of serum E 2 , LH, FHS, IGF-I and leptin levels were helpful for the early diagnosis of ICPP. (author)

  16. IGF-I at 9 and 36 months of age — relations with body composition and diet at 3 years — the SKOT cohort

    DEFF Research Database (Denmark)

    Ejlerskov, Katrine Tschentscher; Larnkjær, A.; Pedersen, D.

    2014-01-01

    Objective High infancy levels of insulin-like growth factor-I (IGF-I) have been associated with increased linear growth and fat-free mass (FFM) but also with risk of obesity. This paper examines how IGF-I at 9 and 36 months relates to diet and body composition. Design Healthy term infants from...... and values were considerably higher in girls (43%). Children breastfed at 9 months had lower IGF-I concentrations at 9 months but reached the same IGF-I concentrations at 36 months as infants not breastfed at 9 months. IGF-I at 36 months was positively associated with height, weight, BMI, predicted FFM...... and FFM index (FFM/height (kg/m2)). Although there also was a positive association with predicted fat mass (FM) there was no association with FM index (FM/height (kg/m2)). Further, a negative association with skin fold thickness was observed. A change in IGF-I from 9–36 months was positively related...

  17. Polymorphism of Insulin-like growth factor-I (IGF-I gene and their effect on growth traits in Indonesia native chicken

    Directory of Open Access Journals (Sweden)

    M.A Mu'in

    2009-12-01

    Full Text Available The research was aimed is to detect Insulin-like growth factor-I (IGF-I gene polymorphism and their effect on growth traits in Indonesia natives chicken. Seventy two Indonesian native chicken are going to be used in this research. The polymorphism of IGF-I gene was detected by PCR-RFLP/Pst-I. Four growth traits (body weight at 1, 2, 3, and 4 months were recorded for analyzing the association between IGF-I gene polymorphism and growth performance.The results showed that allele A (621 bp and allele B (364 and 257 bp were found in this research. It was found that Indonesian native chicken carried high frequencies of allele A (0.82, and frequencies of IGF-I genotypes (AA, AB, BB were 68.0, 27.8, and 4,2%, respectively. When compared to the IGF-I genotypes, the BB genotype had the highest body weight at 1, 2, 3, and 4 month (P<0.05. The results showed that the B allele was positive of associated to a higher growth rate. Therefore, these results suggest that there is a possibility of IGF-I genotypes acting as a molecular marker for growth rate of Indonesia native.

  18. Insulin-like growth factor (IGF)-I obliterates the pregnancy-associated protection against mammary carcinogenesis in rats: evidence that IGF-I enhances cancer progression through estrogen receptor-α activation via the mitogen-activated protein kinase pathway

    International Nuclear Information System (INIS)

    Thordarson, Gudmundur; Slusher, Nicole; Leong, Harriet; Ochoa, Dafne; Rajkumar, Lakshmanaswamy; Guzman, Raphael; Nandi, Satyabrata; Talamantes, Frank

    2004-01-01

    Pregnancy protects against breast cancer development in humans and rats. Parous rats have persistently reduced circulating levels of growth hormone, which may affect the activity of the growth hormone/insulin-like growth factor (IGF)-I axis. We investigated the effects of IGF-I on parity-associated protection against mammary cancer. Three groups of rats were evaluated in the present study: IGF-I-treated parous rats; parous rats that did not receive IGF-I treatment; and age-matched virgin animals, which also did not receive IGF-I treatment. Approximately 60 days after N-methyl-N-nitrosourea injection, IGF-I treatment was discontinued and all of the animal groups were implanted with a silastic capsule containing 17β-estradiol and progesterone. The 17β-estradiol plus progesterone treatment continued for 135 days, after which the animals were killed. IGF-I treatment of parous rats increased mammary tumor incidence to 83%, as compared with 16% in parous rats treated with 17β-estradiol plus progesterone only. Tumor incidence and average number of tumors per animal did not differ between IGF-I-treated parous rats and age-matched virgin rats. At the time of N-methyl-N-nitrosourea exposure, DNA content was lowest but the α-lactalbumin concentration highest in the mammary glands of untreated parous rats in comparison with age-matched virgin and IGF-I-treated parous rats. The protein levels of estrogen receptor-α in the mammary gland was significantly higher in the age-matched virgin animals than in untreated parous and IGF-I-treated parous rats. Phosphorylation (activation) of the extracellular signal-regulated kinase-1/2 (ERK1/2) and expression of the progesterone receptor were both increased in IGF-I-treated parous rats, as compared with those in untreated parous and age-matched virgin rats. Expressions of cyclin D 1 and transforming growth factor-β 3 in the mammary gland were lower in the age-matched virgin rats than in the untreated parous and IGF-I-treated parous

  19. The effect of HMB ingestion on the IGF-I and IGF binding protein response to high intensity military training.

    Science.gov (United States)

    Redd, Michael J; Hoffman, Jay R; Gepner, Yftach; Stout, Jeffrey R; Hoffman, Mattan W; Ben-Dov, Daniel; Funk, Shany; Church, David D; Avital, Guy; Chen, Yacov; Frankel, Hagai; Ostfeld, Ishay

    2017-02-01

    Insulin-like growth factor-I (IGF-I) is a metabolic and anabolic biomarker that has been proposed to reflect physiological adaptations resulting from multistressor environments. The bioactivity of IGF-I is regulated by seven different insulin-like growth factor binding proteins (IGFBPs) which act not only as carriers of IGF-1, but also function as a modulator of IGF-I availability and activity. Supplementing with β-hydroxy-β-methylbutyrate (HMB) has been shown to enhance physiological outcomes associated with intense training, and has been reported to augment the IGF-1 response. The purpose of this study was to examine the effect of 23days of HMB supplementation on circulating levels of IGF-I and IGFBPs in combat soldiers during highly intense military training. Thirteen male soldiers from an elite infantry unit volunteered to participate in this double-blind, parallel design study. Soldiers were provided 3g·day -1 of either HMB (n=6) or placebo (PL; n=7). During the study soldiers performed advanced military training with periods of restricted sleep and severe environmental stressors. Blood samples were obtained prior to (PRE) and approximately 18h following the final supplement consumption (POST). No significant differences were observed for circulating IGF-1 concentrations between HMB and PL (p=0.568). In addition, no differences were seen between the groups for IGFBP-1 (p=1.000), IGFBP-2 (p=0.855), IGFBP-3 (p=0.520), IGFBP-4 (p=0.103), IGFBP-5 (p=0.886), or IGFBP-6 (p=0.775). A significant difference was noted between HMB (169.9±23.0ng·ml -1 ) and PL (207.2±28.0ng·ml -1 ) for IGFBP-7 at POST (p=0.042). Although the results of this study do not support the influence of HMB supplementation on circulating concentrations of IGF-1 or IGFBPs1-6 during high intensity military training, it does present initial evidence that it may lower circulating IGFBP-7 concentrations. This may provide some indication of a reduced stress response, but further investigation on

  20. Liver-derived IGF-I contributes to GH-dependent increases in lean mass and bone mineral density in mice with comparable levels of circulating GH.

    Science.gov (United States)

    Nordstrom, Sarah M; Tran, Jennifer L; Sos, Brandon C; Wagner, Kay-Uwe; Weiss, Ethan J

    2011-07-01

    The relative contributions of circulating and locally produced IGF-I in growth remain controversial. The majority of circulating IGF-I is produced by the liver, and numerous mouse models have been developed to study the endocrine actions of IGF-I. A common drawback to these models is that the elimination of circulating IGF-I disrupts a negative feedback pathway, resulting in unregulated GH secretion. We generated a mouse with near total abrogation of circulating IGF-I by disrupting the GH signaling mediator, Janus kinase (JAK)2, in hepatocytes. We then crossed these mice, termed JAK2L, to GH-deficient little mice (Lit). Compound mutant (Lit-JAK2L) and control (Lit-Con) mice were treated with equal amounts of GH such that the only difference between the two groups was hepatic GH signaling. Both groups gained weight in response to GH but there was a reduction in the final weight of GH-treated Lit-JAK2L vs. Lit-Con mice. Similarly, lean mass increased in both groups, but there was a reduction in the final lean mass of Lit-JAK2L vs. Lit-Con mice. There was an equivalent increase in skeletal length in response to GH in Lit-Con and Lit-JAK2L mice. There was an increase in bone mineral density (BMD) in both groups, but Lit-JAK2L had lower BMD than Lit-Con mice. In addition, GH-mediated increases in spleen and kidney mass were absent in Lit-JAK2L mice. Taken together, hepatic GH-dependent production of IGF-I had a significant and nonredundant role in GH-mediated acquisition of lean mass, BMD, spleen mass, and kidney mass; however, skeletal length was dependent upon or compensated for by locally produced IGF-I.

  1. Changes of Cerebral and/or Peripheral Adenosine A1 Receptor and IGF-I Concentrations under Extended Sleep Duration in Rats

    Directory of Open Access Journals (Sweden)

    Mounir Chennaoui

    2017-11-01

    Full Text Available Extended sleep improves sustained attention and reduces sleep pressure in humans. Downregulation of adenosine A1 receptor (A1R and modulation of the neurotrophic factor insulin growth factor-1 (IGF-I in brain structures controlling attentional capacities could be involved. In the frontal cortex and hippocampus of rats, we measured adenosine A1R and IGF-I protein concentrations after photoperiod-induced sleep extension. Two groups of twelve rats were adapted over 14 days to a habitual (CON 12:12 light–dark (LD schedule and an extended (EXT 16:8 LD schedule. IGF-I content was also measured in plasma, liver, and skeletal muscle. In EXT, compared to CON rats, A1R content in the frontal cortex was significantly lower (p < 0.05, while IGF-I content was higher (p < 0.001, and no significant change was observed in the hippocampus. IGF-I content in plasma and muscle was higher (p < 0.001 and p < 0.01, while it was lower in liver (p < 0.001. The absolute weight and weight gain were higher in EXT rats (p < 0.01. These data suggest that 14 days under a 16:8 LD photoperiod respectively down- and upregulated cortical A1R and IGF-I levels. This photoperiod induced an anabolic profile with increased weight gain and circulating and muscular IGF-I levels. An extension of sleep duration might favor cerebral and peripheral anabolism, which may help attentional and physical capacities.

  2. Regulation of insulin-like growth factor I receptors on vascular smooth muscle cells by growth factors and phorbol esters.

    Science.gov (United States)

    Ververis, J J; Ku, L; Delafontaine, P

    1993-06-01

    Insulin-like growth factor I (IGF I) is an important mitogen for vascular smooth muscle cells. To characterize regulation of vascular IGF I receptors, we performed radioligand displacement experiments using rat aortic smooth muscle cells (RASMs). Serum deprivation for 48 hours caused a 40% decrease in IGF I receptor number. Exposure of quiescent RASMs to platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), or angiotensin II (Ang II) caused a 1.5-2.0-fold increase in IGF I receptors per cell. After FGF exposure, there was a marked increase in the mitogenic response to IGF I. IGF I downregulated its receptors in the presence of platelet-poor plasma. Stimulation of protein kinase C (PKC) by exposure of quiescent RASMs to phorbol 12-myristate 13-acetate caused a biphasic response in IGF I binding; there was a 42% decrease in receptor number at 45 minutes and a 238% increase at 24 hours. To determine the role of PKC in growth factor-induced regulation of IGF I receptors, we downregulated PKC by exposing RASMs to phorbol 12,13-dibutyrate (PDBu) for 48 hours. PDGF- and FGF- but not Ang II-mediated upregulation of IGF I receptors was completely inhibited in PDBu-treated cells. Thus, acute PKC activation by phorbol esters inhibits IGF I binding, whereas chronic PKC activation increases IGF I binding. PDGF and FGF but not Ang II regulate vascular IGF I receptors through a PKC-dependent pathway. These data provide new insights into the regulation of vascular smooth muscle cell IGF I receptors in vitro and are of potential importance in characterizing vascular proliferative responses in vivo.

  3. Rehydrating dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Christian Hellert

    2017-05-01

    Full Text Available Dye sensitized solar cells (DSSCs are silicon free, simply producible solar cells. Longevity, however, is a longstanding problem for DSSCs. Due to liquid electrolytes being commonly used, evaporation of the electrolyte causes a dramatic drop in electric output as cells continue to be used unmaintained. Stopping evaporation has been tried in different ways in the past, albeit with differing degrees of success. In a recent project, a different route was chosen, exploring ways of revitalizing DSSCs after varying periods of usage. For this, we focused on rehydration of the cells using distilled water as well as the electrolyte contained in the cells. The results show a significant influence of these rehydration procedures on the solar cell efficiency. In possible applications of DSSCs in tents etc., morning dew may thus be used for rehydration of solar cells. Refillable DSSCs can also be used in tropical climates or specific types of farms and greenhouses where high humidity serves the purpose of rehydrating DSSCs.

  4. Do IGF-I concentrations better reflect growth hormone (GH action in children with short stature than the results of GH stimulating tests? Evidence from the simultaneous assessment of thyroid function

    Directory of Open Access Journals (Sweden)

    Smyczyńska Joanna

    2011-01-01

    Full Text Available Abstract Background The diagnosis of growth hormone (GH deficiency (GHD in short children seems unquestionable when both GH peak in stimulating tests (GHST and IGF-I concentration are decreased. However, the discrepancies between the results of GHST and IGF-I secretion are observed. It seems purposeful to determine the significance of GHST and IGF-I assessment in diagnosing GHD. The relationship between GH secretion and thyroid function, as well as GH influence on the peripheral thyroxine (T4 to triiodothyronine (T3 deiodination, mediated by IGF-I, were identified. Thus, clear differences in thyroid function between GH-deficient and non-GH-deficient subjects should exist. Methods Analysis comprised 800 children (541 boys, age 11.6 ± 3.1 years (mean ± SD, with short stature, in whom two (2 standard GHST (with clonidine and with glucagon were performed and IGF-I, free T4 (FT4, free T3 (FT3 and TSH serum concentrations were assessed. The patients were qualified to the following groups: GHD - decreased GH peak in GHST and IGF-I SDS (n = 81, ISS - normal GH peak and IGF-I SDS (n = 347, low GH - normal IGF-I SDS, and decreased GH peak (n = 212, low IGF - decreased IGF-I SDS, and normal GH peak (n = 160. The relationships among the results of particular tests were evaluated. Results In the groups with decreased IGF-I concentrations (GHD Group and low IGF Group, the more severe deficit of height was observed, together with higher TSH and FT4 but lower FT3 levels than in groups with normal IGF-I concentrations (ISS Group and low GH Group, independently of the results of GHST. TSH, FT4 and FT3 concentrations were - respectively - similar in two groups with decreased IGF-I secretion, as well as in two groups with normal IGF-I levels. Significant correlations were found between patients' height SDS and IGF-I SDS, between FT3 and IGF-I SDS (positive, and between FT4 and IGF-I SDS (negative, with no correlation between GH peak and any of the parameters

  5. Long-term insulin-like growth factor-I expression in skeletal muscles attenuates the enhanced in vitro proliferation ability of the resident satellite cells in transgenic mice

    Science.gov (United States)

    Chakravarthy, M. V.; Fiorotto, M. L.; Schwartz, R. J.; Booth, F. W.

    2001-01-01

    Insulin-like growth factor-I (IGF-I) overexpression for 1-month in mouse skeletal muscle increases satellite cell proliferation potential. However, it is unknown whether this beneficial enhancement by IGF-I expression would persist over a longer-term duration in aged mice. This is an important issue to address if a prolonged course of IGF-I is to be used clinically in muscle-wasting conditions where satellite cells may become limiting. Using the IGF-I transgenic (IGF-I Tg) mouse that selectively expresses the IGF-I transgene in striated muscles, we found that 18-months of continuous IGF-I overexpression led to a loss in the enhanced in vitro proliferative capacity of satellite cells from Tg skeletal muscles. Also 18-month-old IGF-I Tg satellite cells lost the enhanced BrdU incorporation, greater pRb and Akt phosphorylations, and decreased p27(Kip1) levels initially observed in cells from 1-month-old IGF-I Tg mice. The levels of those biochemical markers reverted to similar values seen in the 18-months WT littermates. These findings, therefore, suggest that there is no further beneficial effect on enhancing satellite cell proliferation ability with persistent long-term expression of IGF-I in skeletal muscles of these transgenic mice.

  6. Disposition of radiolabelled insulin-like growth factor I (IGF-I), IGF-II and their N-terminal truncated variants in rats

    International Nuclear Information System (INIS)

    Yamamoto, Hiroyuki; Kato, Yuzuru; Murphy, L.J.

    1996-01-01

    Serum half life, tissue uptake and urinary excretion of N-terminal truncated IGF variants and their intact precursors were compared to see whether the variants regulate the bioavailability of those growth factors. IGF-I, des(1-3) IGF-I, IGF-II and des(1-6) IGF-II were labeled with 125 I and intravenously administered to SD rats. Blood from femoral artery and urine from implanted bladder catheter were collected at appropriate intervals until sacrifice of animals at 2 hr after administration. Tissues were dissected out and all of these samples were measured for their radioactivity with a gamma counter. The half lives of des(1-3) IGF-I, IGF-I, des(1-6) IGF-II and IGF-II were 20.5, 228.3, 21.3 and 181.7 min, respectively. Maximal accumulation of all peptides was found in the kidney. 125 I-IGF-I and -II showed the following distribution pattern; levels were higher in the kidney>pancreas>small intestine>liver>duodenum>stomach>lung>spleen>heart>large intestine>testis>brain>skeletal muscle. Skeletal muscle, kidney and testis showed a preferential uptake of the variants. Urinary excretion of the variants were much greater. Thus the variants were more rapidly cleared from circulation. The physiological significance of tissue distribution of 4 peptides remains to be further investigated. (K.H.)

  7. Development and clinical evaluation of a novel immunoassay for the binary complex of IGF-I and IGF-binding protein-1 in human serum

    DEFF Research Database (Denmark)

    Frystyk, Jan; Højlund, Kurt; Rasmussen, Kirsten Nyborg

    2002-01-01

    Correlation studies have suggested that IGF-binding protein (IGFBP)-1 is a dynamic regulator of free IGF-I. To further study this, we developed a monoclonal immunofluorometric assay specific for the binary complex of IGF-I and IGFBP-1 in human serum. An IGFBP-1 antibody, which recognizes all...... phospho-forms of IGFBP-1, was used for coating. An europium-labeled IGF-I antibody served as tracer. Assay incubation was performed at conditions approaching those in vivo (i.e. pH 7.4, 37 C). The assay was highly specific: no signal was obtained unless both IGF-I and IGFBP-1 were present and neither...... IGFBP-2, -3, -4, nor IGF-II caused any cross-reaction. The linear standard curve covered 3 orders of magnitude, and within and in-between assay coefficients of variation were less than 5 and 15%, respectively. To study the dynamic relationship between free IGF-I and binary complex formation, seven...

  8. Interaction of insulin-like growth factor I with porcine thyroid cells cultured in monolayer

    International Nuclear Information System (INIS)

    Saji, M.; Tsushima, T.; Isozaki, O.; Murakami, H.; Ohba, Y.; Sato, K.; Arai, M.; Mariko, A.; Shizume, K.

    1987-01-01

    The interaction of insulin-like growth factor I (IGF-I) with porcine thyroid cells cultured in monolayer was studied. Specific binding of [ 125 I]iodo-IGF-I to thyroid cells was a reversible process dependent on the time and temperature of incubation. A steady state was achieved in 18 h at 4 C and averaged 14.2 +/- 2% (mean +/- SD)/10(6) cells. Binding of [ 125 I]iodo-IGF-I was inhibited by unlabeled IGF-I; half-maximal inhibition occurred at concentrations of 2-5 ng/ml. Multiplication-stimulating activity (rat IGF-II) and pork insulin had relative potencies of 1:20 and 1:300 compared with IGF-I. Scatchard analysis of binding data revealed a single class of IGF-I receptors with a Ka of 4.3 X 10(10) M-1, 49,000 binding sites were estimated per cell. Affinity cross-linking and autoradiography demonstrated the presence of type I IGF receptors. Thyroid cells also had specific receptors for insulin, but specific binding of [ 125 I]iodoinsulin was much lower than that of [ 125 I]iodo-IGF-I. Preincubation of thyroid cells with IGF-I or insulin caused a concentration-dependent decrease in [ 125 I]iodo-IGF-I binding due to an apparent loss of receptors. Preincubation with epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, or TSH did not alter subsequent binding of [ 125 I]iodo-IGF-I. Low concentrations of IGF-I stimulated DNA synthesis and proliferation of thyroid cells and acted synergistically with epidermal growth factor. Multiplication-stimulating activity and insulin had relative potencies in stimulating DNA synthesis comparable to their abilities to inhibit the binding of [ 125 I]iodo-IGF-I to thyroid cells

  9. Radiation sensitivity of mammalian cells

    International Nuclear Information System (INIS)

    Koch, C.J.

    1985-01-01

    The authors tested various aspects of the so-called ''competition'' model for radiation sensitization/protection. In this model, sensitizers and/or protectors react in first order chemical reactions with radiation-induced target radicals in the cell, producing damage fixation or repair respectively. It is only because of these parallel, first-order competing reactions that they may assign net amounts of damage on the basis of the chemical reactivity of the sentiziers/protectors with the radicals. It might be expected that such a simple model could not explain all aspects of cellular radiosensitivity and this has indeed been found to be true. However, one is able, with the simple model, to pose quite specific questions, and obtain quantitative information with respect to the relative agreement between experiment and theory. Many experiments by several investigators have found areas of disagreement with the competition theory, particularly with respect to the follow items: 1) role of cellular glutathione as the most important endogeneous radiation protector 2) characteristics of various sensitizers which cause them to behave differently from each other 3) methods relating to the quantitative kinetic analysis of experimenal results. This paper addresses these specific areas of disagreement from both an experimental and theoretical basis

  10. Clinical singnificance of determination of changes of serum and peritoneal fluid TGF-β, IGF-I, TNF-α and IL-8 levels in patients with endometriosis

    International Nuclear Information System (INIS)

    Zao Yuhua; Zhang Juhong; Ma Yunbao

    2006-01-01

    Objective: To investigate the clinical significance of the changes of serum and peritioneal fluid TGF-β, IGF - I , TNF-α and IL-8 levels in patients with endometriosis. Methods: Serum and peritoneal fluid levels of TGF-β, IGF-I, TNF-α and IL-8 were measured with RIA in 30 patients with endometriosis and 30 controls. Results: The levels of TGF-β, IGF-I, TNF-α and IL-8 in serum and peritoneal fluid in endometriosis group were significantly higher than those in the controls (P<0.05), moreover, the levels of the markers in peritoneal fluid were significantly higher than those in serum (P<0.05). Conclusion: It is likely that elevation of serum and peritoneal fluid levels of the markers may play a role in the pathogenesis of endometriosis. (authors)

  11. Postpartum IGF-I and IGFBP-2 levels are prospectively associated with the development of type 2 diabetes in women with previous gestational diabetes mellitus.

    Science.gov (United States)

    Lappas, M; Jinks, D; Shub, A; Willcox, J C; Georgiou, H M; Permezel, M

    2016-12-01

    Women with previous gestational diabetes mellitus (GDM) are at greater risk of developing type 2 diabetes. In the general population, the insulin-like growth factor (IGF) system has been implicated in the development of type 2 diabetes. The aim of this study was to determine if circulating IGF-I, IGF-II, IGFBP-1 and IGFBP-2 levels 12weeks following a GDM pregnancy are associated with an increased risk of developing type 2 diabetes. IGF-I, IGF-II, IGFBP-1 and IGFBP-2 levels were measured in 98 normal glucose tolerant women, 12weeks following an index GDM pregnancy using enzyme immunoassay. Women were assessed for up to 10years for the development of overt type 2 diabetes. Among the 98 women with previous GDM, 21 (21%) developed diabetes during the median follow-up period of 8.5years. After adjusting for age and BMI, IGF-I and IGFBP-2 were significantly associated with the development of type 2 diabetes. In a clinical model of prediction of type 2 diabetes that included age, BMI, pregnancy fasting glucose and postnatal fasting glucose, the addition of IGF-I and IGFBP-2 resulted in an improvement in the net reclassification index of 17.8%. High postpartum IGF-I and low postpartum IGFBP-2 levels are a significant risk factor for the development of type 2 diabetes in women with a previous history of GDM. This is the first report that identifies IGF-I and IGFBP-2 as a potential biomarker for the prediction of type 2 diabetes in women with a history of GDM. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Chronic alcohol consumption, type 2 diabetes mellitus, insulin-like growth factor-I (IGF-I), and growth hormone (GH) in ethanol-treated diabetic rats.

    Science.gov (United States)

    Kim, Soo-Jeong; Ju, Anes; Lim, Seul-Gi; Kim, Dai-Jin

    2013-11-13

    Alcohol has deleterious influences on glucose metabolism which may contribute to the development of type 2 diabetes mellitus (T2DM). Insulin-like growth factor I (IGF-I) and growth hormone (GH), which interact with insulin to modulate metabolic control, have been shown to be related to impaired glucose tolerance. This study was conducted to assess the possibility that altered circulating IGF-I and GH levels contribute to the exacerbation of T2DM by alcohol use in type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats. OLETF rats were pair-fed a Lieber-DeCarli Regular Ethanol diet and LETO rats were pair-fed a control diet for 6 weeks. At 6 weeks, an Intraperitoneal Glucose Tolerance Test (IP-GTT) was performed and IGF-I and GH levels were evaluated. Prior to an IP-GTT, OLETF-Ethanol (O-E) group had significantly a decrease in the mean glucose levels compared to OLETF-Control (O-C) group. At 120 min post IP-GTT, the O-E group had significantly an increase in the mean glucose levels compared to O-C group. The serum IGF-I levels were significantly lower and the serum GH levels were significantly higher in the O-E group than in L-C group. These results suggest that IGF-I and GH are prominent in defining the risk and development of T2DM, and may be adversely affected by heavy alcohol use, possibly mediating its diabetogenic effects. Thus, the overall glucose intolerance in the setting of alcoholism may be attributable to inappropriate alteration of IGF-I and GH levels. © 2013. Published by Elsevier Inc. All rights reserved.

  13. Is further evaluation for growth hormone (GH) deficiency necessary in fibromyalgia patients with low serum insulin-like growth factor (IGF)-I levels?

    Science.gov (United States)

    Yuen, Kevin C J; Bennett, Robert M; Hryciw, Cheryl A; Cook, Marie B; Rhoads, Sharon A; Cook, David M

    2007-02-01

    Fibromyalgia (FM) is characterized by diffuse pain, fatigue, and sleep disturbances; symptoms that resemble the adult growth hormone (GH) deficiency syndrome. Many FM patients have low serum GH levels, with a hypothesized aetiology of dysregulated GH/insulin-like growth factor (IGF)-I axis. The aim of this study was to assess the GH reserve in FM patients with low serum IGF-I levels using the GH-releasing hormone (GHRH)-arginine test. We retrospectively reviewed the GHRH-arginine data of 77 FM patients with low serum IGF-I levels referred to our tertiary unit over a 4-year period. Of the 77 FM patients, 13 patients (17%) failed the GHRH-arginine test. Further evaluation with pituitary imaging revealed normal pituitary glands (n=7), coincident microadenomas (n=4), empty sella (n=1) and pituitary cyst (n=1), and relevant medical histories such as previous head injury (n=4), Sheehan's syndrome (n=1), and whiplash injury (n=1). In contrast, the remaining 64 patients (83%) that responded to the GHRH-arginine test demonstrated higher peak GH levels compared to age and BMI-matched controls (n=24). Our data shows that a subpopulation of FM patients with low serum IGF-I levels will fail the GHRH-arginine test. We, thus, recommend that the GH reserve of these patients should be evaluated further, as GH replacement may potentially improve the symptomatology of those with true GH deficiency. Additionally, the increased GH response rates to GHRH-arginine stimulation in the majority of FM patients with low serum IGF-I levels further supports the hypothesis of a dysregulated GH/IGF-I axis in the pathophysiology of FM.

  14. Serum insulin-like growth factor I (IGF-I) and IGF-binding protein 3 levels are increased in central precocious puberty

    DEFF Research Database (Denmark)

    Juul, A; Scheike, Thomas Harder; Nielsen, C T

    1995-01-01

    Central precocious puberty (CPP) is characterized by early activation of the pituitary-gonadal axis, which leads to increased growth velocity and development of secondary sexual characteristics. It is generally believed that gonadal sex steroids stimulate pulsatile GH secretion, which, in turn......, stimulates insulin-like growth factor I (IGF-I) and IGF-binding protein 3 (IGFBP-3) production. However, little is known about GH, IGF-I, and IGFBP-3 serum levels in children with precocious puberty. Treatment of CPP by GnRH agonists has become the treatment of choice. However, the effect of long term...

  15. Effects of an endurance cycling competition on resting serum insulin-like growth factor I (IGF-I) and its binding proteins IGFBP-1 and IGFBP-3

    Science.gov (United States)

    Chicharro, J; Lopez-Calderon, A; Hoyos, J; Martin-Velasco, A; Villa, G; Villanua, M; Lucia, A

    2001-01-01

    Objectives—To determine whether consecutive bouts of intense endurance exercise over a three week period alters serum concentrations of insulin-like growth factor I (IGF-I) and/or its binding proteins. Methods—Seventeen professional cyclists (mean (SEM) VO2MAX, 74.7 (2.1) ml/kg/min; age, 27 (1) years) competing in a three week tour race were selected as subjects. Blood samples were collected at each of the following time points: t0 (control, before the start of competition), t1 (end of first week), and t3 (end of third week). Serum levels of both total and free IGF-I and IGF binding proteins 1 and 3 (IGFBP-1 and IGFBP-3) were measured in each of the samples. Cortisol levels were measured in nine subjects. Results—A significant (p<0.01) increase was found in total IGF-I and IGFBP-1 at both t1 and t3 compared with to (IGF-I: 110.9 (17.7), 186.8 (12.0), 196.9 (14.7) ng/ml at t0, t1, and t3 respectively; IGFBP-1: 54.6 (6.6), 80.6 (8.0), and 89.2 (7.9) ng/ml at t0, t1, and t3 respectively). A significant (p<0.01) decrease was noted in free IGF-I at t3 compared with both to and t1 (t0: 0.9 (0.1) ng/ml; t1: 0.9 (0.1) ng/ml; t3: 0.7 (0.1) ng/ml); in contrast, IGFBP-3 levels remained stable throughout the race. Conclusions—It would appear that the increase in circulating levels of both IGF-I and its binding protein IGFBP-1 is a short term (one week) endocrine adaptation to endurance exercise. After three weeks of training, total IGF-I and IGFBP-1 remained stable, whereas free IGF-I fell below starting levels. Key Words: cycling; insulin-like growth factor; exercise; endurance; binding proteins PMID:11579061

  16. Serum insulin-like growth factor-I (IGF-I) and growth in children born after assisted reproduction

    DEFF Research Database (Denmark)

    Kai, Claudia Mau; Main, Katharina M; Andersen, Anders Nyboe

    2006-01-01

    CONTEXT: Concern has been raised about the safety of assisted reproduction techniques for the offspring. OBJECTIVES: The objective of the study was to investigate postnatal growth and growth factors in children born after intra-cytoplasmatic sperm injection (ICSI) and in vitro fertilization (IVF...... their target height (sd score) at 3 yr of age [mean -0.91 (1.2)], compared with NC children [-0.61 (0.9), P = 0.033]. In the child cohort, target height attainment (sd score) and growth factors did not differ among the three groups. CONCLUSIONS: The overall growth pattern of ICSI and IVF children in both...... cohorts was normal. Our findings of subtle differences in target height attainment and serum IGF-I levels between infants born after assisted reproduction techniques and controls may not be clinically significant. However, these observations indicate that further systematic follow-up of growth and puberty...

  17. High serum levels of growth hormone (GH) and insulin-like growth factor-I (IGF-I) during high-dose GH treatment in short children born small for gestational age

    NARCIS (Netherlands)

    M. van Dijk (Marije); P.G.H. Mulder (Paul); E.C.A.M. Houdijk (Mieke); J.C. Mulder (Jaap); K. Noordam (Kees); R.J.H. Odink (Roelof); C. Rongen-Westerlaken (Ciska); P.G. Voorhoeve (Paul); J.J.J. Waelkens (Johan); W.H. Stokvis-Brantsma; A.C.S. Hokken-Koelega (Anita)

    2006-01-01

    textabstractContext: Epidemiological studies have indicated that high serum levels of GH and IGF-I are associated with long-term risks. Objective: The objective of the study was to evaluate the changes in serum levels of GH during overnight profiles, IGF-I, and IGF binding protein 3 (IGFBP-3) in

  18. Low serum levels of free and total insulin-like growth factor I (IGF-I) in patients with anorexia nervosa are not associated with increased IGF-binding protein-3 proteolysis

    DEFF Research Database (Denmark)

    Støving, R K; Flyvbjerg, A; Frystyk, J

    1999-01-01

    Patients with anorexia nervosa (AN) are GH resistant, with elevated GH levels and low serum levels of total insulin-like growth factor I (IGF-I). IGF-I action is modulated by IGF-binding proteins (IGFBPs), and a variety of catabolic states has been characterized by the presence of increased IGFBP-3...

  19. Clinical significance of measurment of changes of serum IGF-I, hs-CRP levels after treatment in patients with hyperthyroidism and hypothyroidism

    International Nuclear Information System (INIS)

    Zhu Conggang

    2009-01-01

    Objective: To explore the clinical significance of changes of serum IGF-I,hs-CRP levels after treatment in patients with hyperthyroidism and hypothyroidism. Methods: Serum IGF-I, hs-CRP(with RIA), and serum hs-CRP with immuno-turbidity methods levels were determined both before and after treatment in 36 cases of hyperthyroidism 30 cases of hypothyroidism as well as 35 controls. Results: Before treatment, the serum IGF-I levels in patients with hyperthyroidism were significantly higher and the levels in patients with hypothyroidism were significantly lower than those in controls (both P<0.01). After treatment for 3 months,the levels were much corrected, but still remained significantly different from those in controls (P<0.05). Before treatment serum hs-CRP levels in both groups of patients were significantly higher than those in controls (P<0.01), but after treatment,the levels were not much different from those in controls. Conclusion: Serum levels of IGF-I and hs-CRP were closely related to the disease process in patients with hyperthyroidism as well as in patients with hypothyroidism, and were much corrected after trentment.(authors)

  20. Utility of circulating IGF-I as a biomarker for assessing body composition changes in men during periods of high physical activity superimposed upon energy and sleep restriction.

    Science.gov (United States)

    Nindl, Bradley C; Alemany, Joseph A; Kellogg, Mark D; Rood, Jennifer; Allison, Steven A; Young, Andrew J; Montain, Scott J

    2007-07-01

    Insulin-like growth factor (IGF)-I is a biomarker that may have greater utility than other conventional nutritional biomarkers in assessing nutritional, health, and fitness status. We hypothesized that the IGF-I system would directionally track a short-term energy deficit and would be more related to changes in body composition than other nutritional biomarkers. Thirty-five healthy men (24 +/- 0.3 yr) underwent 8 days of exercise and energy imbalance. Total and free IGF-I, IGF binding proteins-1, -2, and -3, the acid labile subunit, transferrin, ferritin, retinol binding protein, prealbumin, testosterone, triiodothyronine, thyroxine, and leptin responses were measured. Dual-energy X-ray absorptiometry assessed changes in body mass and composition. Repeated-measures ANOVA, correlation analysis, and receiver operator characteristic curves were used for statistical analyses (P losing >5% body mass. The IGF-I system is an important adjunct in the overall assessment of adaptation to stress imposed by high levels of physical activity superimposed on energy and sleep restriction and is more closely associated with losses in body mass and fat-free mass than other conventional nutritional biomarkers.

  1. An IGF-I promoter polymorphism modifies the relationships between birth weight and risk factors for cardiovascular disease and diabetes at age 36

    Directory of Open Access Journals (Sweden)

    Stehouwer Coen DA

    2005-06-01

    Full Text Available Abstract Objective To investigate whether IGF-I promoter polymorphism was associated with birth weight and risk factors for cardiovascular disease (CVD and type 2 diabetes (T2DM, and whether the birth weight – risk factor relationship was the same for each genotype. Design and participants 264 subjects (mean age 36 years had data available on birth weight, IGF-I promoter polymorphism genotype, CVD and T2DM risk factors. Student's t-test and regression analyses were applied to analyse differences in birth weight and differences in the birth weight – risk factors relationship between the genotypes. Results Male variant carriers (VCs of the IGF-I promoter polymorphism had a 0.2 kg lower birth weight than men with the wild type allele (p = 0.009. Of the risk factors for CVD and T2DM, solely LDL concentration was associated with the genotype for the polymorphism. Most birth weight – risk factor relationships were stronger in the VC subjects; among others the birth weight – systolic blood pressure relationship: 1 kg lower birth weight was related to an 8.0 mmHg higher systolic blood pressure Conclusion The polymorphism in the promoter region of the IGF-I gene is related to birth weight in men only, and to LDL concentration only. Furthermore, the genotype for this polymorphism modified the relationships between birth weight and the risk factors, especially for systolic and diastolic blood pressure.

  2. Genomewide meta-analysis identifies loci associated with IGF-I and IGFBP-3 levels with impact on age-related traits

    NARCIS (Netherlands)

    A. Teumer (Alexander); Q. Qi; M. Nethander (Maria); H. Aschard (Hugues); S. Bandinelli (Stefania); M. Beekman (Marian); S.I. Berndt (Sonja); M. Bidlingmaier (Martin); L. Broer (Linda); A.R. Cappola (Anne); Ceda, G.P. (Gian Paolo); S.J. Chanock (Stephen); M.-H. Chen (Ming-Huei); Chen, T.C. (Tai C.); Y.D. Chen (Y.); Chung, J. (Jonathan); Del Greco Miglianico, F. (Fabiola); J. Eriksson (Joel); L. Ferrucci (Luigi); N. Friedrich (Nele); C. Gnewuch (Carsten); M. Goodarzi (Mark); N. Grarup (Niels); Guo, T. (Tingwei); Hammer, E. (Elke); R.B. Hayes (Richard); A.A. Hicks (Andrew); A. Hofman (Albert); J.J. Houwing-Duistermaat (Jeanine); Hu, F. (Frank); D. Hunter (David); L.L.N. Husemoen (Lise Lotte); A.J. Isaacs (Aaron); K.B. Jacobs (Kevin); J.A.M.J.L. Janssen (Joseph); J.-O. Jansson (John-Olov); Jehmlich, N. (Nico); Johnson, S. (Simon); A. Juul (Anders); M. Karlsson (Magnus); T.O. Kilpeläinen (Tuomas); P. Kovacs (Peter); P. Kraft (Peter); Li, C. (Chao); A. Linneberg (Allan); Y. Liu (YongMei); R.J.F. Loos (Ruth); M. Lorentzon (Mattias); Y. Lu (Yingchang); M. Maggio (Marcello); R. Mägi (Reedik); J.B. Meigs (James); D. Mellström (Dan); M. Nauck (Matthias); A.B. Newman (Anne B.); M.N. Pollak (Michael); P.P. Pramstaller (Peter Paul); I. Prokopenko (Inga); B.M. Psaty (Bruce); M. Reincke (Martin); E.B. Rimm (Eric B.); Rotter, J.I. (Jerome I.); Saint Pierre, A. (Aude); C. Schurmann (Claudia); S. Seshadri (Sudha); Sjögren, K. (Klara); P.E. Slagboom (Eline); Strickler, H.D. (Howard D.); M. Stumvoll (Michael); Y. Suh (Yousin); Q. Sun (Qi); Zhang, C. (Cuilin); Svensson, J. (Johan); T. Tanaka (Toshiko); Tare, A. (Archana); A. Tönjes (Anke); H.-W. Uh (Hae-Won); C.M. van Duijn (Cornelia); D. van Heemst (Diana); L. Vandenput (Liesbeth); R.S. Vasan (Ramachandran Srini); U. Völker (Uwe); S.M. Willems (Sara); C. Ohlsson (Claes); H. Wallaschofski (Henri); R.C. Kaplan (Robert)

    2016-01-01

    textabstractThe growth hormone/insulin-like growth factor (IGF) axis can be manipulated in animal models to promote longevity, and IGF-related proteins including IGF-I and IGF-binding protein-3 (IGFBP-3) have also been implicated in risk of human diseases including cardiovascular diseases, diabetes,

  3. Toward the insulin-IGF-I intermediate structures: Functional and structural properties of the [TyrB25NMePheB26] insulin mutant

    Czech Academy of Sciences Publication Activity Database

    Žáková, Lenka; Brynda, Jiří; Au-Alvarez, O.; Dodson, G. D.; Whittingham, J. L.; Brzozowski, A. M.

    2004-01-01

    Roč. 43, - (2004), s. 16293-16300 ISSN 0006-2960 R&D Projects: GA MŠk LN00B030 Institutional research plan: CEZ:AV0Z4055905 Keywords : insulin * IGF -I * Structures Subject RIV: CE - Biochemistry Impact factor: 4.008, year: 2004

  4. The essential role of IGF-I: lessons from the long-term study and treatment of children and adults with Laron syndrome.

    Science.gov (United States)

    Laron, Z

    1999-12-01

    Fifty patients with primary GH resistance (Laron syndrome) due to molecular defects of the GH receptor or post-receptor pathways were followed from infancy through adulthood. This condition leading to long-term insulin-like growth factor-I (IGF-I) deprivation caused marked growth retardation (-4 to 8 height SD), acromicia, organomicria, retarded development of the skeletal and muscular systems, a small cranium, slow motor development, and impairment of intellectual development in some of the patients. In addition, there was progressive obesity, insulin resistance, a tendency for hypoglycemia, followed later in life by hypercholesterolemia and by glucose intolerance and even diabetes. IGF-I treatment of children with Laron syndrome, by our and other groups (150-240 microg/day sc), stimulated growth (8 cm in the first year and 4-5 cm in the following years) and normalized the biochemical abnormalities. Overdosage led to adverse effects such as hypoglycemia, edema, swelling of soft tissues, and hyperandrogenism. It is concluded that primary IGF-I deprivation induces severe auxological, biochemical, and hormonal changes, the only treatment being biosynthetic IGF-I administration.

  5. A common polymorphism in the promoter of the IGF-I gene associates with increased fasting serum triglyceride levels in glucose-tolerant subjects

    DEFF Research Database (Denmark)

    Nielsen, Eva-Maria D; Hansen, Lars; Lajer, Maria

    2004-01-01

    The aim of the present study was to examine if absence of a common allele in a microsatellite polymorphism in the insulin-like growth factor I (IGF-I) promoter was associated with type 2 diabetes and alterations in quantitative traits in glucose-tolerant subjects....

  6. Cartilage formation measured by a novel PIINP assay suggests that IGF-I does not stimulate but maintains cartilage formation ex vivo

    DEFF Research Database (Denmark)

    Madsen, S H; Sondergaard, B C; Jensen, Anne-Christine Bay

    2009-01-01

    explants were cultured in Dulbecco's modified Eagle's medium (DMEM):F12 in the presence of 0, 0.01, 0.1, 1, 10, or 100 ng/mL of IGF-I. The viability of the chondrocytes was measured by the colorimetric Alamar blue assay. Collagen formation was assessed from the conditioned medium by the PIINP assay...

  7. Plasma IGF-I, INSL3, testosterone, inhibin concentrations and scrotal circumferences surrounding puberty in Japanese Black beef bulls with normal and abnormal semen.

    Science.gov (United States)

    Weerakoon, W W P N; Sakase, M; Kawate, N; Hannan, M A; Kohama, N; Tamada, H

    2018-07-01

    The relationships between semen abnormalities and peripheral concentrations of testicular and metabolic hormones in beef bulls are unclear. Here we compared plasma insulin-like growth factor I (IGF-I), insulin-like peptide 3 (INSL3), testosterone, inhibin concentrations, and scrotal circumferences surrounding puberty in Japanese Black beef bulls (n = 66) with normal or abnormal semen. We collected blood samples and measured scrotal circumferences monthly from 4 to 24 months of age. Semen was collected weekly from 12 months until at least 18 months of age. Fresh semen was evaluated for semen volume, sperm motility, concentrations, and morphological defects. The normal fresh semen was frozen by a standard method and examined for post-thaw sperm motility and fertility. Bulls were classified as having either normal post-thaw semen (n = 45) or abnormal semen (n = 21, when at least one of the above test items was abnormal for 6 months). Abnormal semen was classified into abnormal fresh or low-fertility post-thaw which evaluated for rates of transferable embryos. The abnormal fresh was categorized as having sperm morphological defects, low motility, and morphological defects plus low motility. Scrotal circumferences were smaller for the abnormal-semen group vs. the normal-semen group at 20 and 24 months (p IGF-I, INSL3, and inhibin concentrations in the abnormal-semen group were lower than those of the normal-semen group (p IGF-I; 6, 9, 11-14, 17, and 20-21 months for INSL3; 5, 8-13, 16, 17, 19, and 20 months for inhibin). The plasma testosterone concentrations were lower in the abnormal-semen bulls vs. normal-semen bulls only at 22 months (p IGF-I and inhibin concentrations for low-fertility post-thaw semen (p IGF-I, INSL3, and inhibin surrounding puberty may be associated with semen aberration in beef bulls. Notably, the combined sperm abnormality of morphological defects and low motility in fresh semen could involve lowered INSL3, whereas the low

  8. CLINICAL AND HORMONAL MILIEU OF 9 PATIENTS WITH PRIMARY GROWTH HORMONE INSENSITIVITY SYNDROME AND THEIR RESPONSE TO IGF-I GENERATION TEST

    Directory of Open Access Journals (Sweden)

    M. Razzaghy-Azar

    2006-05-01

    Full Text Available Primary growth hormone insensitivity syndrome (GHIS is a rare entity which can be due to defects in growth hormone (GH receptor that is called type 1 Laron syndrome (T1LS or post receptor defects (type 2 Laron syndrome . The aim of study was determining the clinical and hormonal milieu of the patients with primary GHIS and their response to IGF-I (insulin like growth factor-I generation test (IGT. GH, IGF-I, IGF-II, IGF binding protein 1 and 3 (BP-1 and BP-3, GH binding protein (GHBP and anti-GH antibody were detected by ELISA and RIA methods. IGF-I and BP-3 were measured before and after IGT. Nine patients (8 males, 1 female (mean age ± SD, 6.4 ± 5 years with severe short stature and high GH level were studied. Height SDS was - 8.5 ± 2.6. In 7 patients GHBP was zero, IGF-I and BP-3 were low and did not increase after IGT, so they had T1LS. Two brothers did not show the hormonal milieu of GH receptor defect, and were called non Laron syndrome (NLS. Birth weight in patients with T1LS and NLS was 3.65 ± 0.2 Kg and 1.65 ± 0.2 Kg, respectively (P = 0.001. All of the patients had typical clinical feature of GH-deficiency, but nasal bridge depression and microphallus were not seen in NLS. GH treatment of NLS, normalized their growth velocity, but without catch up growth. In conclusion IGT can differentiate Laron syndrome from other types of short stature. GH and IGF-I of fetus have no role in intrauterine growth.

  9. Retardation of fetal dendritic development induced by gestational hyperglycemia is associated with brain insulin/IGF-I signals.

    Science.gov (United States)

    Jing, Yu-Hong; Song, Yan-Feng; Yao, Ya-Ming; Yin, Jie; Wang, De-Gui; Gao, Li-Ping

    2014-10-01

    Hyperglycemia is an essential risk factor for mothers and fetuses in gestational diabetes. Clinical observation has indicated that the offspring of mothers with diabetes shows impaired somatosensory function and IQ. However, only a few studies have explored the effects of hyperglycemia on fetal brain development. Neurodevelopment is susceptible to environmental conditions. Thus, this study aims to investigate the effects of maternal hyperglycemia on fetal brain development and to evaluate insulin and insulin-like growth factor-I (IGF-I) signals in fetal brain under hyperglycemia or controlled hyperglycemia. At day 1 of pregnancy, gestational rats were intraperitoneally injected with streptozocin (60 mg/kg). Some of the hyperglycemic gestational rats were injected with insulin (20 IU, two times a day) to control hyperglycemia; the others were injected with saline of equal volume. The gestational rats were sacrificed at days 14, 16, and 18 of embryo development. The dendritic spines of subplate cortex neurons in the fetal brain were detected by Golgi-Cox staining. The mRNA levels of insulin receptors (IRs) and IGF-IR in the fetal brain were measured using qRT-PCR. The protein levels of synaptophysin, IR, and IGF-IR in the fetal brain were detected by western blot. No significant difference in fetal brain formation was observed between the maternal hyperglycemic group and insulin-treated group. By contrast, obvious retardation of dendritic development in the fetus was observed in the maternal hyperglycemic group. Similarly, synaptophysin expression was lower in the fetus of the maternal hyperglycemic group than in that of the insulin-treated group. The mRNA and protein expression levels of IRs in the fetal brain were higher in the hyperglycemic group than in the insulin-treated group. By contrast, the levels of IGF-IR in the brain were lower in the fetus of the maternal hyperglycemic group than in that of the insulin-treated group. These results suggested that

  10. Dye-sensitized solar cells based on purple corn sensitizers

    Science.gov (United States)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  11. High-intensity interval training (HIIT) increases insulin-like growth factor-I (IGF-I) in sedentary aging men but not masters' athletes: an observational study.

    Science.gov (United States)

    Herbert, Peter; Hayes, Lawrence D; Sculthorpe, Nicholas; Grace, Fergal M

    2017-03-01

    The aim of this investigation was to examine the impact high-intensity interval training (HIIT) on serum insulin-like growth factor-I (IGF-I) in active compared with sedentary aging men. 22 lifetime sedentary (SED; 62 ± 2 years) and 17 masters' athletes (LEX; 60 ± 5 years) were recruited to the study. As HIIT requires preconditioning exercise in sedentary cohorts, the study required three assessment phases; enrollment (phase A), following preconditioning exercise (phase B), and post-HIIT (phase C). Serum IGF-I was determined by electrochemiluminescent immunoassay. IGF-I was higher in LEX compared to SED at baseline (p = 0.007, Cohen's d = 0.91), and phase B (p = 0.083, Cohen's d = 0.59), with only a small difference at C (p = 0.291, Cohen's d = 0.35). SED experienced a small increase in IGF-I following preconditioning from 13.1 ± 4.7 to 14.2 ± 6.0 μg·dl -1 (p = 0.376, Cohen's d = 0.22), followed by a larger increase post-HIIT (16.9 ± 4.4 μg·dl -1 ), which was significantly elevated compared with baseline (p = 0.002, Cohen's d = 0.85), and post-preconditioning (p = 0.005, Cohen's d = 0.51). LEX experienced a trivial changes in IGF-I from A to B (18.2 ± 6.4 to 17.2 ± 3.7 μg·dl -1 [p = 0.538, Cohen's d = 0.19]), and a small change post-HIIT (18.4 ± 4.1 μg·dl -1 [p = 0.283, Cohen's d = 0.31]). Small increases were observed in fat-free mass in both groups following HIIT (p HIIT with preconditioning exercise abrogates the age associated difference in IGF-I between SED and LEX, and induces small improvements in fat-free mass in both SED and LEX.

  12. Eco RV RFLP at the insulin-like growth factor I (IGF I) locus on chromosome 12

    Energy Technology Data Exchange (ETDEWEB)

    Schneid, H; Noguiez, P; Girard, F; Binoux, M; Le Bouc, Y [INSERM U 142, Paris (France)

    1988-09-26

    The human liver IFG I cDNA insert from the {lambda}TG03 (1) was subcloned in PGEM4 (pTG 3906). The 660 bp Eco RI-Bam HI fragment containing the 5{prime} untranslated, the coding and the 3{prime} untranslated region of the IGF IA gene (exons 1, 2, 3 and 5) was used. Eco RV digestion of genomic DNA and hybridization with the IGF I probe reveals invariant fragments of 20; 8, 7 and 5 kb and polymorphic fragments of 13 kb (allele 1) and 11, 5 kb (allele 2). The frequency of alleles was studied in 51 unrelated European Caucasians. Co-dominant segregation was observed in 2 European families (9 individuals). Hind III and Pvu II digestions show previous described RFLP. Allelic frequencies however were: Hind III (5, 2 kb allele = 0, 14 and 4, 9 kb allele = 0, 86) and Pvu II (5 kb allele = 0, 14 and 4, 7 kb allele = 0, 86). Hind III and Pvu II RFLPs are linked. Among the DNA of the 14 individuals, where Eco RV RFLP was found, only one exhibited Hind III and Pvu II RFLPs.

  13. Growth and Growth hormone - Insulin Like Growth Factor -I (GH-IGF-I) Axis in Chronic Anemias.

    Science.gov (United States)

    Soliman, Ashraf T; De Sanctis, Vincenzo; Yassin, Mohamed; Adel, Ashraf

    2017-04-28

    Anaemia is a global public health problem affecting both developing and developed countries with major consequences for human health as well as social and economic development. It occurs at all stages of the life cycle, but is more prevalent in pregnant women and young children. Iron deficiency anaemia (IDA) was considered to be among the most important contributing factors to the global burden of disease. Prolonged and/or chronic anemia has a negative effect on linear growth especially during the rapid phases (infancy and puberty). Additionally infants with chronic IDA have delayed cognitive, motor, and affective development that may be long-lasting. In view of the significant impact of chronic anemias on growth, pediatricians endocrinologists and hematologists should advocate primary prevention and screening for growth disturbance in these forms of anemias. The extent of the negative effect of different forms of chronic anemias on linear growth and its possible reversibilty is addressed in this review. The possible mechanisms that may impair growth in the different forms of anemias are addressed with special attention to their effect on the growth hormone (GH) - insulin like growth factor -I (IGF-I).

  14. Effects of eccentric cycling exercise on IGF-I splice variant expression in the muscles of young and elderly people

    DEFF Research Database (Denmark)

    Hameed, M.; Toft, A.D.; Harridge, S.D.

    2008-01-01

    growth factor (MGF) were studied in response to 1 h of eccentric cycling exercise in young and old individuals. Subjects (nine young, aged 20-27 years and eight elderly, aged 67-75 years) completed an eccentric exercise protocol that consisted of 60 min of reverse pedal cycling. Workloads were chosen......Recovery from micro damage resulting from intensive exercise has been shown to take longer in older muscles. To investigate the factors that may contribute to muscle repair, we have studied the expression of two splice variants of the insulin-like growth factor-I (IGF-I) gene. IGF-IEa and mechano....... No difference was observed between the baseline levels of the two splice variants between the two subject groups. Eccentric cycling exercise resulted in a significant increase in the mean MGF mRNA in both young and old subjects but did not alter IGF-IEa mRNA levels in either age group. As reported previously...

  15. New avenues in hypoxic cell sensitization

    International Nuclear Information System (INIS)

    Huilgol, N.G.; Chatterjee, N.A.; Singh, B.B.

    1995-01-01

    Hypoxic cells in tumors represent a population of cells that are resistant to radiotherapy. Bio-reductive agents like RSU 1069, RBU 6145 and EOg and vasoactive drugs in conjunction with hypoxic cell sensitizers are being evaluated as hypoxic cell cytotoxins. Chlorpromazine a membrane active drug and AK-2123- a nitrotriazole with a potential to deplete intracellular thiols induced vasoconstriction and sensitize hypoxic cells have stretched the boundaries of innovation. A preliminary experience with these drugs is discussed. 8 refs., 2 tabs., 2 figs

  16. Electrochemistry and dye-sensitized solar cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav

    2017-01-01

    Roč. 2, č. 1 (2017), s. 88-98 ISSN 2451-9103 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : electrochemistry * dye-sensitized cells * photoelectrode Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

  17. study on the serum levels of E2, IL-6 and IGF-I in patients with post-menopausal osteoporosis (PMO)

    International Nuclear Information System (INIS)

    Lv Kuan; Liu Chunyu; Lu Yingju

    2006-01-01

    Objective: To study the changes of serum levels of E 2 , IL-6, IGF-I in patients with post-menopausal osteoporosis (PMO). Methods: Serum levels of E 2 (with CLIA), IL-6, IGF-I, BGP (with RIA) were measured in the following subjects: (1) 32 patients with PMO (2) 32 post-menopausal women without PMO and (3) 30 pre-menopausal controls. Serum P, Ca and AKP levels were also determined. Results: As a whole, serum levels of IL -6 in postmenopausal women were higher than those in controls. Levels in subjects with PMO were significantly higher than those without PMO (P 2 and BMD index (r=-0. 587, - 0. 438 respectively, P 2 and BMD index (r=0.569, 0.433 respectively, P 2 levels will in someway promote the expression of IL-6 ( osteoclastic) and reduce the expression of IGF-I (osteoclastic), resulting in lessening of bone mass. HRT, despite of the controversy over cardio-vascalar safety, is beneficial for osteoporosis. (authors)

  18. Changes in calcitropic hormones, bone markers and insulin-like growth factor I (IGF-I) during pregnancy and postpartum: a controlled cohort study.

    Science.gov (United States)

    Møller, U K; Streym, S; Mosekilde, L; Heickendorff, L; Flyvbjerg, A; Frystyk, J; Jensen, L T; Rejnmark, L

    2013-04-01

    Pregnancy and lactation cause major changes in calcium homeostasis and bone metabolism. This population-based cohort study presents the physiological changes in biochemical indices of calcium homeostasis and bone metabolism during pregnancy and lactation We describe physiological changes in calcium homeostasis, calcitropic hormones and bone metabolism during pregnancy and lactation. We studied 153 women planning pregnancy (n=92 conceived) and 52 non-pregnant, age-matched female controls. Samples were collected prior to pregnancy, once each trimester and 2, 16 and 36 weeks postpartum. The controls were followed in parallel. P-estradiol (E2), prolactin and 1,25-dihydroxyvitamin D (1,25(OH)2D) increased (phormone (P-PTH) and calcitonin decreased (pgrowth factor I (IGF-I) was suppressed (pbone resorption and formation rose and fall, respectively (pbone formation markers increased in association with IGF-I changes (pbone turnover markers were associated with lactation status (pbone markers indicated a negative bone balance. The rise in bone formation in late pregnancy may be initiated by a spike in IGF-I levels. The high bone turnover in lactating women may be related to high prolactin and PTH levels, low E2 levels and perhaps increased parathyroid hormone-related protein levels.

  19. Maternal exposure to UV filters: associations with maternal thyroid hormones, IGF-I/IGFBP3 and birth outcomes.

    Science.gov (United States)

    Krause, M; Frederiksen, H; Sundberg, K; Jørgensen, F S; Jensen, L N; Nørgaard, P; Jørgensen, C; Ertberg, P; Petersen, J H; Feldt-Rasmussen, U; Juul, A; Drzewiecki, K T; Skakkebaek, N E; Andersson, A M

    2018-02-01

    Several chemical UV filters/absorbers ('UV filters' hereafter) have endocrine-disrupting properties in vitro and in vivo . Exposure to these chemicals, especially during prenatal development, is of concern. To examine maternal exposure to UV filters, associations with maternal thyroid hormone, with growth factor concentrations as well as to birth outcomes. Prospective study of 183 pregnant women with 2nd trimester serum and urine samples available. Maternal concentrations of the chemical UV filters benzophenone-1 (BP-1) and benzophenone-3 (BP-3) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well as birth outcomes (weight, height, and head and abdominal circumferences) were examined. Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T 3 ), thyroxine (T 4 ), insulin-like growth factor I (IGF-I) and its binding protein IGFBP3 were observed in mothers carrying male fetuses. Male infants of mothers in the middle 4-HBP exposure group had statistically significantly lower weight and shorter head and abdominal circumferences at birth compared to the low exposure group. Widespread exposure of pregnant women to chemical UV filters and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long-term consequences of the exposure to UV filters on fetal development and children's health. © 2018 The authors.

  20. Dye-sensitized solar cells based on purple corn sensitizers

    International Nuclear Information System (INIS)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-01-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  1. Dye-sensitized solar cells based on purple corn sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Phinjaturus, Kawin [Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Maiaugree, Wasan [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Suriharn, Bhalang [Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimanpaeng, Samuk; Amornkitbamrung, Vittaya [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand)

    2016-09-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  2. Interaction of Mechanical Load with Growth Hormone (GH) and Insulin-Like Growth Factor I (IGF-I) on Slow-Twitch Skeletal Muscle and Bone

    Science.gov (United States)

    Linderman, Jon K.; Gosselink, Kristin L.; Wang, Tommy J.; Mukku, Venkat R.; Grindeland, Richard E.

    1994-01-01

    Exogenous humoral growth factors, combined with increased mechanical loading, reportedly induce hypertrophy of fast-, but not slow-twitch skeletal muscles, and have little effect in attenuating atrophy of slow-twitch muscle associated with exposure to microgravity in animals with intact neuroendocrine systems. These observations suggest that anabolic adjuvants and muscle tension do not interact to stimulate growth or maintenance of slow-twitch skeletal muscle. The purpose of the present study was to determine whether a chronic increase in mechanical loading (synergistic ablation) or hindlimb unweighting (hindlimb suspension) interact with exogenous GH and IGF-I (Genentech, So San Francisco, CA) in the slow-twitch soleus muscles of female rats (approx. 250 g). Bilateral ablation of the plantaris and gastrocnemius muscles induced 38% and 40% increases in the absolute (mg/pair) and relative (mg/100 g body weight) weights of the soleus, respectively (p less than or = 0.05), in ambulatory rats. GH and IGF-I interacted with chronic loading to increase absolute soleus mass an additional 20% (p less than or = 0.05), and mixed and myofibrillar protein contents an additional 12% and 7%, respectively (NS). In contrast, hindlimb suspension (HLS) resulted in 20% and 18% decreases in the absolute and relative weights of the soleus, respectively (p less than or = 0.05); GH and IGF-I did not spare loss of soleus mass or protein content in HLS rats. HLS decreased tibial plate thickness approx. 11% (p less than or = 0.05), but not weights of the tibia or femus. GH and IGF-I increased tibial plate thickness approx. 30% (p less than or = 0.05), in ambulatory and HLS rats, and increased femur and tibial weights 12% (p less than or = 0.05) and 8% (NS), respectively, in ambulatory rats, but had no effect in HLS rats. Results of the present investigation suggest that GH and IGF-I can stimulate hypertrophy of slow-twitch skeletal muscle when chronically overloaded, but can also stimulate

  3. Effects of short-term caloric restriction on circulating free IGF-I, acid-labile subunit, IGF-binding proteins (IGFBPs)-1-4, and IGFBPs-1-3 protease activity in obese subjects

    DEFF Research Database (Denmark)

    Rasmussen, Michael Højby; Juul, Anders; Kjems, Lise Lund

    2006-01-01

    , no published data exist on free IGF-I levels, acid labile subunit (ALS), or IGFBP protease activity in relation to GH release during a hypocaloric diet. The main purpose of this study was to determine free IGF-I, ALS, IGFBPs-1-4, and IGFBPs-1-3 protease activity in relation to 24-h GH release before and after......Decreased levels of GH and total IGF-I have been reported in obesity. It has been hypothesized that increased free (biologically active) IGF-I levels generated from IGF-binding protein (IGFBP) protease activity could be the mechanism for the low GH release in dieting obese subjects. However...... a short-term very low-calorie diet (VLCD)....

  4. Effects of short-term caloric restriction on circulating free IGF-I, acid-labile subunit, IGF-binding proteins (IGFBPs)-1-4, and IGFBPs-1-3 protease activity in obese subjects

    DEFF Research Database (Denmark)

    Rasmussen, Michael Højby; Juul, Anders; Kjems, Lise Lund

    2006-01-01

    Decreased levels of GH and total IGF-I have been reported in obesity. It has been hypothesized that increased free (biologically active) IGF-I levels generated from IGF-binding protein (IGFBP) protease activity could be the mechanism for the low GH release in dieting obese subjects. However......, no published data exist on free IGF-I levels, acid labile subunit (ALS), or IGFBP protease activity in relation to GH release during a hypocaloric diet. The main purpose of this study was to determine free IGF-I, ALS, IGFBPs-1-4, and IGFBPs-1-3 protease activity in relation to 24-h GH release before and after...... a short-term very low-calorie diet (VLCD)....

  5. X-rays sensitive mammalian cell mutant

    International Nuclear Information System (INIS)

    Utsumi, Hiroshi

    1982-01-01

    A phenomenon that in x-ray-sensitive mammalian-cell mutants, cellular death due to x-ray radiation was not increased by caffeine, but on the contrary, the dead cells were resuscitated by it was discussed. The survival rate of mutant cells increased by caffein in a low concentration. This suggested that caffeine may have induced some mechanism to produce x-ray resistant mutant cells. Postirradiation treatment with caffeine increased considerably the survival rate of the mutant cells, and this suggested the existence of latent caffeine-sensitive potentially lethal damage repair system. This system, after a few hours, is thought to be substituted by caffeine-resistant repair system which is induced by caffeine, and this may be further substituted by x-ray-resistant repair system. The repair system was also induced by adenine. (Ueda, J.)

  6. Albendazole sensitizes cancer cells to ionizing radiation

    International Nuclear Information System (INIS)

    Patel, Kirtesh; Doudican, Nicole A; Schiff, Peter B; Orlow, Seth J

    2011-01-01

    Brain metastases afflict approximately half of patients with metastatic melanoma (MM) and small cell lung cancer (SCLC) and represent the direct cause of death in 60 to 70% of those affected. Standard of care remains ineffective in both types of cancer with the challenge of overcoming the blood brain barrier (BBB) exacerbating the clinical problem. Our purpose is to determine and characterize the potential of albendazole (ABZ) as a cytotoxic and radiosensitizing agent against MM and SCLC cells. Here, ABZ's mechanism of action as a DNA damaging and microtubule disrupting agent is assessed through analysis of histone H2AX phosphorylation and cell cyle progression. The cytotoxicity of ABZ alone and in combination with radiation therapy is determined though clonogenic cell survival assays in a panel of MM and SCLC cell lines. We further establish ABZ's ability to act synergistically as a radio-sensitizer through combination index calculations and apoptotic measurements of poly (ADP-ribose) polymerase (PARP) cleavage. ABZ induces DNA damage as measured by increased H2AX phosphorylation. ABZ inhibits the growth of MM and SCLC at clinically achievable plasma concentrations. At these concentrations, ABZ arrests MM and SCLC cells in the G2/M phase of the cell cycle after 12 hours of treatment. Exploiting the notion that cells in the G2/M phase are the most sensitive to radiation therapy, we show that treatment of MM and SCLC cells treated with ABZ renders them more sensitive to radiation in a synergistic fashion. Additionally, MM and SCLC cells co-treated with ABZ and radiation exhibit increased apoptosis at 72 hours. Our study suggests that the orally available antihelminthic ABZ acts as a potent radiosensitizer in MM and SCLC cell lines. Further evaluation of ABZ in combination with radiation as a potential treatment for MM and SCLC brain metastases is warranted

  7. Albendazole sensitizes cancer cells to ionizing radiation

    Science.gov (United States)

    2011-01-01

    Background Brain metastases afflict approximately half of patients with metastatic melanoma (MM) and small cell lung cancer (SCLC) and represent the direct cause of death in 60 to 70% of those affected. Standard of care remains ineffective in both types of cancer with the challenge of overcoming the blood brain barrier (BBB) exacerbating the clinical problem. Our purpose is to determine and characterize the potential of albendazole (ABZ) as a cytotoxic and radiosensitizing agent against MM and SCLC cells. Methods Here, ABZ's mechanism of action as a DNA damaging and microtubule disrupting agent is assessed through analysis of histone H2AX phosphorylation and cell cyle progression. The cytotoxicity of ABZ alone and in combination with radiation therapy is determined though clonogenic cell survival assays in a panel of MM and SCLC cell lines. We further establish ABZ's ability to act synergistically as a radio-sensitizer through combination index calculations and apoptotic measurements of poly (ADP-ribose) polymerase (PARP) cleavage. Results ABZ induces DNA damage as measured by increased H2AX phosphorylation. ABZ inhibits the growth of MM and SCLC at clinically achievable plasma concentrations. At these concentrations, ABZ arrests MM and SCLC cells in the G2/M phase of the cell cycle after 12 hours of treatment. Exploiting the notion that cells in the G2/M phase are the most sensitive to radiation therapy, we show that treatment of MM and SCLC cells treated with ABZ renders them more sensitive to radiation in a synergistic fashion. Additionally, MM and SCLC cells co-treated with ABZ and radiation exhibit increased apoptosis at 72 hours. Conclusions Our study suggests that the orally available antihelminthic ABZ acts as a potent radiosensitizer in MM and SCLC cell lines. Further evaluation of ABZ in combination with radiation as a potential treatment for MM and SCLC brain metastases is warranted. PMID:22094106

  8. Photochromic dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Noah M. Johnson

    2015-11-01

    Full Text Available We report the fabrication and characterization of photochromic dye sensitized solar cells that possess the ability to change color depending on external lighting conditions. This device can be used as a “smart” window shade that tints, collects the sun's energy, and blocks sunlight when the sun shines, and is completely transparent at night.

  9. Oxygen-dependent sensitization of irradiated cells

    International Nuclear Information System (INIS)

    Ewing, D.; Powers, E.L.

    1979-01-01

    Attention is focused primarily on O 2 effects in three biological systems, all tested in suspension: bacterial spores, vegetative bacterial cells, and mammalian cells. Information from these systems shows that O 2 has more than one process through which it can act. Studies with bacterial spore suspensions provide clear evidence that multiple components to oxygen-dependent radiation sensitization exist. Studies with mammalian cell suspensions also show that at least two oxygen-dependent sensitization processes can be distinguished. Similar studies with vegetative bacteria in suspension have not resolved oxic sensitization into components. The roles of water-derived radicals in radiation sensitivity and, specifically, in sensitization by O 2 were examined. OH radicals are clearly implicated in damage in all three biological test systems. However, the specific roles proposed for OH radicals are different in these organisms. In bacterial spores, OH radical removal in itself does not protect in anoxia or in high concentrations of O 2 . OH radical removal over a limited intermediate range of O 2 concentrations will, however, protect. OH radical scavenging probably results in the formation of the actual protector. In bacteria, the supposition is that OH radical removal will protect both in anoxia and in the presence of O 2 . OH radicals probably react with a cellular target molecule and leave a radicalsite; this is the site which can then react with O 2 to cause damage; DNA is the likely cellular target. In mammalian cells, a reaction scheme, similar to that proposed for bacteria, has been suggested for O 2 -dependent sensitization

  10. Recent Advances in Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Umer Mehmood

    2014-01-01

    Full Text Available Solar energy is an abundant and accessible source of renewable energy available on earth, and many types of photovoltaic (PV devices like organic, inorganic, and hybrid cells have been developed to harness the energy. PV cells directly convert solar radiation into electricity without affecting the environment. Although silicon based solar cells (inorganic cells are widely used because of their high efficiency, they are rigid and manufacturing costs are high. Researchers have focused on organic solar cells to overcome these disadvantages. DSSCs comprise a sensitized semiconductor (photoelectrode and a catalytic electrode (counter electrode with an electrolyte sandwiched between them and their efficiency depends on many factors. The maximum electrical conversion efficiency of DSSCs attained so far is 11.1%, which is still low for commercial applications. This review examines the working principle, factors affecting the efficiency, and key challenges facing DSSCs.

  11. Studies on binding and mitogenic effect of insulin and insulin-like growth factor I in glomerular mesangial cells

    International Nuclear Information System (INIS)

    Conti, F.G.; Striker, L.J.; Lesniak, M.A.; MacKay, K.; Roth, J.; Striker, G.E.

    1988-01-01

    The mesangial cells are actively involved in regulating glomerular hemodynamics. Their overlying endothelium is fenestrated; therefore, these cells are directly exposed to plasma substances, including hormones such as insulin and insulin-like growth factor I (IGF-I). These peptides may contribute to the mesangial sclerosis and cellular hyperplasia that characterize diabetic glomerulopathy. We report herein the characterization of the receptors and the mitogenic effects of IGF-I and insulin on mouse glomerular mesangial cells in culture. The IGF-I receptor was characterized on intact cells. The Kd of the IGF-I receptor was 1.47 X 10(-9) M, and the estimated number of sites was 64,000 receptors/cell. The binding was time, temperature, and pH dependent, and the receptor showed down-regulation after exposure to serum. The expression of the receptor did not change on cells at different densities. The specific binding for insulin was too low to allow characterization of the insulin receptor on intact cells. However, it was possible to identify the insulin receptor in a wheat germ agglutinin-purified preparation of solubilized mesangial cells. This receptor showed the characteristic features of the insulin receptor, including pH dependence of binding and a curvilinear Scatchard plot. The mitogenic effects of insulin and IGF-I on mesangial cells were measured by the incorporation of [3H]thymidine into DNA. IGF-I was more potent than insulin. The half-maximal response to IGF-I stimulation occurred at 1.3 X 10(-10) M, and a similar increase with insulin was observed at concentrations in the range of 10(-7) M, suggesting that this insulin action was mediated through the IGF-I receptor. These data show that the mouse microvascular smooth muscle cells of the glomerulus express a cell surface receptor for IGF-I in vitro and that this peptide is a potent mitogen for these mesangial cells

  12. Biochemical and hormonal changes induced by one week of administration of rIGF-I to patients with Laron type dwarfism

    DEFF Research Database (Denmark)

    Laron, Z; Klinger, B; Jensen, L T

    1991-01-01

    ) aged 3 1/2 to 37 3/4 years were submitted to seven daily s.c. injections of recombinant IGF-I in doses of 120 or 150 micrograms/kg/day. MEASUREMENTS: Blood samples were drawn before, after three and seven injections, and one week after stopping the trial. RESULTS: The main biochemical and hormonal...... changes registered were (mean +/- SD): a marked rise in serum type III procollagen (PIIINP) from 4.2 +/- 0.9 to 7.3 +/- 2 micrograms/l (P less than 0.0003) and decrease in the following blood components: plasma hGH from 32.51 +/- 43.77 to 4.02 +/- 2.48 mU/l (P less than 0.001), serum cholesterol from 5...... of these effects were transitory, and were found after 3 days therapy but afterwards decreased (insulin, cholesterol and liver tests), others persisted throughout the whole treatment period (hGH, PIINP). CONCLUSIONS: IGF-I mimics the biochemical and hormonal changes described after administration of h...

  13. Niveles séricos de IGF-I e IGFBP-3 en adolescentes embarazadas provenientes de un sector socioeconómico de bajos ingresos

    Directory of Open Access Journals (Sweden)

    Stella Carrasco Rodríguez

    2001-12-01

    Full Text Available El eje de la hormona de crecimiento (GH/factor de crecimiento similar a la insulina tipo-l (IGF-I participa en el crecimiento durantela vida postnatal y fetal y se encuentra regulado por la nutrición. Sin embargo, muy pocos estudios se han adelantado con el fin de comprender los efectos de la mala nutrición sobre dicho eje durante el embarazo en la adolescencia. En este estudio se determinaron los niveles séricos del IGF-I y de IGFBP-3 en un grupo (n=62 de adolescentes en el segundo trimestre de embarazo y provenientes de un estrato pobre de la ciudad de Bogotá y se compararon con los de un grupo (n=36 de adolescentes del mismo estrato. Como referencia se tomaron los valores obtenidos en un grupo (n=20 de adolescentes de un estrato de clase media de la misma ciudad. Se encontró que las adolescentes del estrato pobre presentaban un crecimiento por debajo del percentil 3 con talla y peso significativamente (p

  14. Short- and long-term metabolic effects of recombinant human IGF-I treatment in patients with severe insulin resistance and diabetes mellitus

    DEFF Research Database (Denmark)

    Vestergaard, H; Rossen, M; Urhammer, S A

    1997-01-01

    In patients suffering from the genetic syndromes of severe insulin resistance it appears that diabetes develops when the adaptive hypersecretion of insulin fails and often these forms of diabetes will be insensitive to insulin treatment. The objective of the present study was to examine......-resistant diabetes mellitus and (b) during a long-term (10 weeks) period with rhIGF-I given once a day in a low dose (40 micrograms/kg body weight) in three of the four patients. Two siblings had known mutations in the tyrosine kinase domain of the insulin receptor and a deletion of exon 17 in part of their insulin......-50%), proinsulin (40-50%) and C-peptide (10-65%) and an improvement in glycaemic control as evaluated by decreased glycosylated haemoglobin and serum fructosamine. During the long-term study period blood glucose-lowering effects of rhIGF-I were seen after 2 weeks of treatment and fasting plasma glucose and serum...

  15. High-Methionine Diet Attenuates Severity of Arthritis and Modulates IGF-I Related Gene Expressions in an Adjuvant Arthritis Rats Model

    Directory of Open Access Journals (Sweden)

    Mingxin Li

    2016-01-01

    Full Text Available Rheumatoid arthritis, a synthesized form of adjuvant arthritis exhibited throughout many animal species, inhibits liver function and circulation of IGF-I and contributes to the degradation of skeletal muscle mass. One of the primary goals of the present study is determining whether a high-Methionine (high-Met diet is capable of reducing the adverse effects of arthritis, namely, loss of body mass. Following adjuvant injection, forty arthritic rats were randomly assigned to either a control group with a basal diet or a high-Met group with the same basal diet + 0.5% Methionine. After 14 days all rats were terminated. The high-Met group exhibited an increase in body weight and food intake in comparison with the control group (P<0.05. High-Met diet debilitated arthritis-induced surges in the gastrocnemius in both atrogin-1 and the MuRF1 expressions; however, it was observed to have little to no effect on atrogin-1 and MuRF1 gene expression in soleus. At the same time, high-Met diet rats experienced a rise in IGF-I, with lowering of IGFBP-3 gene expression in the gastrocnemius and the soleus. These data suggest that arthritis severity can be partly attenuated by high-Met diet.

  16. Thyroid hormone modulates insulin-like growth factor-I(IGF-I) and IGF-binding protein-3, without mediation by growth hormone, in patients with autoimmune thyroid diseases.

    Science.gov (United States)

    Inukai, T; Takanashi, K; Takebayashi, K; Fujiwara, Y; Tayama, K; Takemura, Y

    1999-10-01

    The expression and synthesis of insulin-like growth factor-1 (IGF-I) and IGF-binding protein-3 (IGFBP-3) are regulated by various hormones and nutritional conditions. We evaluated the effects of thyroid hormones on serum levels of IGF-I and IGFBP-3 levels in patients with autoimmune thyroid diseases including 54 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis, and in 32 healthy age-matched control subjects. Patients were subdivided into hyperthyroid, euthyroid and hypothyroid groups that were untreated, or were treated with methylmercaptoimidazole (MMI) or L-thyroxine (L-T4). Serum levels of growth hormone (GH), IGF-I and IGFBP-3 were determined by radioimmunoassay. Serum GH levels did not differ significantly between the hyperthyroid and the age-matched euthyroid patients with Graves' disease. The serum levels of IGF-I and IGFBP-3 showed a significant positive correlation in the patients (R=0.616, Phyperthyroid patients with Graves' disease or in those with Hashimoto's thyroiditis induced by excess L-T4 administration than in control subjects. Patients with hypothyroid Graves' disease induced by the excess administration of MMI showed significantly lower IGFBP-3 levels as compared to those in healthy controls (Phormone modulates the synthesis and/or the secretion of IGF-I and IGFBP-3, and this function is not mediated by GH.

  17. Semiconductor quantum dot-sensitized solar cells.

    Science.gov (United States)

    Tian, Jianjun; Cao, Guozhong

    2013-10-31

    Semiconductor quantum dots (QDs) have been drawing great attention recently as a material for solar energy conversion due to their versatile optical and electrical properties. The QD-sensitized solar cell (QDSC) is one of the burgeoning semiconductor QD solar cells that shows promising developments for the next generation of solar cells. This article focuses on recent developments in QDSCs, including 1) the effect of quantum confinement on QDSCs, 2) the multiple exciton generation (MEG) of QDs, 3) fabrication methods of QDs, and 4) nanocrystalline photoelectrodes for solar cells. We also make suggestions for future research on QDSCs. Although the efficiency of QDSCs is still low, we think there will be major breakthroughs in developing QDSCs in the future.

  18. Plasmonic Dye-Sensitized Solar Cells

    KAUST Repository

    Ding, I-Kang

    2010-12-14

    This image presents a scanning electron microscopy image of solid state dye-sensitized solar cell with a plasmonic back reflector, overlaid with simulated field intensity plots when monochromatic light is incident on the device. Plasmonic back reflectors, which consist of 2D arrays of silver nanodomes, can enhance absorption through excitation of plasmonic modes and increased light scattering, as reported by Michael D. McGehee, Yi Cui, and co-workers.

  19. Nanostructured dye-sensitized solar cells

    OpenAIRE

    Palma, Giuseppina

    2014-01-01

    2012/2013 Dye-sensitized solar cells (DSSCs) represent a promising alternative to silicon-based technology. From the first publications about DSSCs in the 90s, they are considered an important breakthrough for achieving high efficiency by using relatively inexpensive and abundant materials. Stability and efficiency are two crucial points in the development of this new class of hybrid photovoltaic devices. Most of the DSSC studies carried out over the past twenty years are based on the o...

  20. Radiation sensitivity of Merkel cell carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J.H.; Ramsay, J.R.; Birrell, G.W. [Queensland Institute of Medical Research (Australia)] [and others

    1995-07-30

    Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.

  1. Radiation sensitivity of Merkell cell carcinoma cell lines

    International Nuclear Information System (INIS)

    Leonard, J. Helen; Ramsay, Jonathan R.; Kearsley, John H.; Birrell, Geoff W.

    1995-01-01

    Purpose: Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Methods and Materials: Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after γ irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. Results: We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to γ irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Conclusion: Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution

  2. Clinical evaluation of hypoxic cell sensitizer (Misonidazole)

    Energy Technology Data Exchange (ETDEWEB)

    Asakawa, Hiroshi (Miyagi Prefectural Adult Disease Center, Natori (Japan)); Watarai, Jiro; Hoshino, Toshiaki

    1984-06-01

    Clinical effectiveness and toxicity of Misonidazole were analyzed and discussed in 22 cases of carcinoma of uterine cervix, 17 cases of esophageal cancer and 11 with other malignancies treated by radiation. By clinical and histologic examination in the controlled trial, it was shown that radiation response of tumor was slightly sensitized in the treated group with this drug, compared with that in the control group. It was confirmed that there was no significant difference between radiation response of tumor in both groups. Peripheral neuropathy was a complication in 10% and toxicodermatitis in 12% even if the total dose administered was below 10 g/m/sup 2/. From these results, it was strongly suggested that this drug is not suitable in combination with simple fractionated irradiation as a hypoxic cell sensitizer.

  3. Recent advances in sensitized mesoscopic solar cells.

    Science.gov (United States)

    Grätzel, Michael

    2009-11-17

    -intensive high vacuum and materials purification steps that are currently employed in the fabrication of all other thin-film solar cells. Organic materials are abundantly available, so that the technology can be scaled up to the terawatt scale without running into feedstock supply problems. This gives organic-based solar cells an advantage over the two major competing thin-film photovoltaic devices, i.e., CdTe and CuIn(As)Se, which use highly toxic materials of low natural abundance. However, a drawback of the current embodiment of OPV cells is that their efficiency is significantly lower than that for single and multicrystalline silicon as well as CdTe and CuIn(As)Se cells. Also, polymer-based OPV cells are very sensitive to water and oxygen and, hence, need to be carefully sealed to avoid rapid degradation. The research discussed within the framework of this Account aims at identifying and providing solutions to the efficiency problems that the OPV field is still facing. The discussion focuses on mesoscopic solar cells, in particular, dye-sensitized solar cells (DSCs), which have been developed in our laboratory and remain the focus of our investigations. The efficiency problem is being tackled using molecular science and nanotechnology. The sensitizer constitutes the heart of the DSC, using sunlight to pump electrons from a lower to a higher energy level, generating in this fashion an electric potential difference, which can exploited to produce electric work. Currently, there is a quest for sensitizers that achieve effective harnessing of the red and near-IR part of sunlight, converting these photons to electricity better than the currently used generation of dyes. Progress in this area has been significant over the past few years, resulting in a boost in the conversion efficiency of the DSC that will be reviewed.

  4. Effects of an evaporative cooling system on plasma cortisol, IGF-I, and milk production in dairy cows in a tropical environment

    Science.gov (United States)

    Titto, Cristiane Gonçalves; Negrão, João Alberto; Titto, Evaldo Antonio Lencioni; Canaes, Taissa de Souza; Titto, Rafael Martins; Pereira, Alfredo Manuel Franco

    2013-03-01

    Access to an evaporative cooling system can increase production in dairy cows because of improved thermal comfort. This study aimed to evaluate the impact of ambient temperature on thermoregulation, plasma cortisol, insulin-like growth factor 1 (IGF-I), and productive status, and to determine the efficiency of an evaporative cooling system on physiological responses under different weather patterns. A total of 28 Holstein cows were divided into two groups, one with and the other without access to a cooling system with fans and mist in the free stall. The parameters were analyzed during morning (0700 hours) and afternoon milking (1430 hours) under five different weather patterns throughout the year (fall, winter, spring, dry summer, and rainy summer). Rectal temperature (RT), body surface temperature (BS), base of tail temperature (TT), and respiratory frequency (RF) were lower in the morning ( P milk production during spring and summer ( P < 0.01).

  5. Burn-induced increase in atrogin-1 and MuRF-1 in skeletal muscle is glucocorticoid independent but downregulated by IGF-I.

    Science.gov (United States)

    Lang, Charles H; Huber, Danuta; Frost, Robert A

    2007-01-01

    The present study determined whether thermal injury increases the expression of the ubiquitin (Ub) E3 ligases referred to as muscle ring finger (MuRF)-1 and muscle atrophy F-box (MAFbx; aka atrogin-1), which are muscle specific and responsible for the increased protein breakdown observed in other catabolic conditions. After 48 h of burn injury (40% total body surface area full-thickness scald burn) gastrocnemius weight was reduced, and this change was associated with an increased mRNA abundance for atrogin-1 and MuRF-1 (3.1- to 8-fold, respectively). Similarly, burn increased polyUb mRNA content in the gastrocnemius twofold. In contrast, there was no burn-induced atrophy of the soleus and no significant change in atrogin-1, MuRF-1, or polyUb mRNA. Burns also did not alter E3 ligase expression in heart. Four hours after administration of the anabolic agent insulin-like growth factor (IGF)-I to burned rats, the mRNA content of atrogin-1 and polyUb in gastrocnemius had returned to control values and the elevation in MuRF-1 was reduced 50%. In contrast, leucine did not alter E3 ligase expression. In a separate study, in vivo administration of the proteasome inhibitor Velcade prevented burn-induced loss of muscle mass determined at 48 h. Finally, administration of the glucocorticoid receptor antagonist RU-486 did not prevent burn-induced atrophy of the gastrocnemius or the associated elevation in atrogin-1, MuRF-1, or polyUb. In summary, the acute muscle wasting accompanying thermal injury is associated with a glucocorticoid-independent increase in the expression of several Ub E3 ligases that can be downregulated by IGF-I.

  6. Association between insulin-like growth factor I (IGF-I microsatellite polymorphisms and important economic traits in pigs Associação entre polimorfismos no marcador microssatélite do gene do fator de crescimento semelhante à insulina I (IGF-I com características de interesse econômico em suínos

    Directory of Open Access Journals (Sweden)

    Danielle Assis de Faria

    2009-02-01

    Full Text Available This study investigated the association between IGF-I microsatellite marker in an F2 population (N=459 generated by mating of native boars to Brazilian commercial sows with performance, carcass cut, and meat quality traits. Association analyses were carried out using a statistical model that included genotype, sex, and group as fixed effects and sire as random effect. The IGF-I genotypes were significantly associated with different quantitative traits and these results corroborate with previous QTL analyses obtained for this chromosome region in swine. Additive and dominance effects, as well as a genotype-sex interaction, were estimated and discussed in the text. According to the results obtained, this marker is suitable for QTL search in the genotyped population.Investigou-se neste trabalho a associação entre o marcador microssatélite IGF-I em uma população F2 (N=459 gerada pelo acasalamento entre suínos nativos brasileiros e fêmeas comerciais com características de desempenho, cortes de carcaça e qualidade da carne. A análise de associação foi feita por meio de um modelo que incluiu genótipo, sexo e grupo como efeitos fixos e pais como efeito aleatório. Os genótipos do IGF-I apresentaram associação significativa com nove características quantitativas, resultados que corroboram análises prévias de QTL obtidas para essa região cromossômica em suínos. Efeitos aditivos de dominância, assim como a interação genótipo × sexo, foram estimados e estão descritos neste trabalho. De acordo com os resultados obtidos, este marcador será útil nas análises de QTL na população analisada.

  7. C-peptide, IGF-I, sex-steroid hormones and adiposity : a cross-sectional study in healthy women within the European Prospective Investigation into Cancer and Nutrition (EPIC)

    NARCIS (Netherlands)

    Bezemer, ID; Rinaldi, S; Dossus, L; van Gils, CH; Peeters, PHM; Noord, PAH; Bueno-de-Mesquita, HB; Johnsen, SP; Overvad, K; Olsen, A; Tjonneland, A; Boeing, H; Lahmann, PH; Linseisen, J; Nagel, G; Allen, N; Roddam, A; Bingham, S; Khaw, KT; Kesse, E; Tehard, B; Clavel-Chapelon, F; Agudo, A; Ardanaz, E; Quiros, [No Value; Amiano, P; Martinez-Garcia, C; Tormo, MJ; Pala, [No Value; Panico, S; Vineis, P; Palli, D; Tumino, R; Trichopoulou, A; Baibas, N; Zilis, D; Hemon, B; Norat, T; Riboli, E; Kaaks, R

    Objectives: The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the

  8. Growth hormone (GH) provocative retesting of 108 young adults with childhood-onset GH deficiency and the diagnostic value of insulin-like growth factor I (IGF-I) and IGF-binding protein-3

    DEFF Research Database (Denmark)

    Juul, A; Kastrup, K W; Pedersen, S A

    1997-01-01

    .e. 45% of patients treated with GH during childhood because of isolated GHD had a normal GH response when retested in adulthood. Multiple regression analysis revealed that peak GH levels were dependent on the degree of hypopituitarism, body mass index, and duration of disease. IGF-I levels were below -2...

  9. complexes as sensitizers for dye sensitized solar cells

    Indian Academy of Sciences (India)

    Compared to N719, H112 sensitizer showed enhanced molar extinction coefficient and relatively better monochromatic incident photon-to-current conversion efficiency (IPCE) across the spectral range of 400 to 800 nm with solar energy-to-electrical conversion efficiency () of 2.43% [open circuit photovoltage (VOC) ...

  10. BODIPYs for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Klfout, Hafsah; Stewart, Adam; Elkhalifa, Mahmoud; He, Hongshan

    2017-11-22

    BODIPY, abbreviation of boron-dipyrromethene, is one class of robust organic molecules that has been used widely in bioimaging, sensing, and logic gate design. Recently, BODIPY dyes have been explored for dye-sensitized solar cells (DSCs). Studies demonstrate their potential as light absorbers for the conversion of solar energy to electricity. However, their photovoltaic performance is inferior to many other dyes, including porphyrin dyes. In this review, several synthetic strategies of BODIPY dyes for DSCs and their further functionalization are described. The photophysical properties of dye molecules and their photovoltaic performances in DSCs are summarized. We aim to provide readers a clear picture of the field and expect to shed light on the next generation of BODIPY dyes for their applications in solar energy conversion.

  11. Early-age feed restriction affects viability and gene expression of satellite cells isolated from the gastrocnemius muscle of broiler chicks

    Directory of Open Access Journals (Sweden)

    Li Yue

    2012-11-01

    Full Text Available Abstract Background Muscle growth depends on the fusion of proliferate satellite cells to existing myofibers. We reported previously that 0–14 day intermittent feeding led to persistent retardation in myofiber hypertrophy. However, how satellite cells respond to such nutritional insult has not been adequately elucidated. Results One-day-old broiler chicks were allocated to control (Con, ad libitum feeding, intermittent feeding (IF, feed provided on alternate days and re-feeding (RF, 2 days ad libitum feeding after 12 days of intermittent feeding groups. Chickens were killed on Day 15 and satellite cells were isolated. When cultured, satellite cells from the IF group demonstrated significant retardation in proliferation and differentiation potential, while RF partly restored the proliferation rate and differentiation potential of the satellite cells. Significant up-regulation of insulin like growth factor I receptor (IGF-IR (P0.05 and thyroid hormone receptor α (TRα (P0.05, and down-regulation of growth hormone receptor (GHR (P0.01 and IGF-I (P0.01 mRNA expression was observed in freshly isolated IF satellite cells when compared with Con cells. In RF cells, the mRNA expression of IGF-I was higher (P0.05 and of TRα was lower (P0.01 than in IF cells, suggesting that RF restored the mRNA expression of TRα and IGF-I, but not of GHR and IGF-IR. The Bax/Bcl-2 ratio tended to increase in the IF group, which was reversed in the RF group (P0.05, indicating that RF reduced the pro-apoptotic influence of IF. Moreover, no significant effect of T3 was detected on cell survival in IF cells compared with Con (PP0.05 cells. Conclusions These data suggest that early-age feed restriction inhibits the proliferation and differentiation of satellite cells, induces changes in mRNA expression of the GH/IGF-I and thyroid hormone receptors in satellite cells, as well as blunted sensitivity of satellite cells to T3, and that RF partially reverses these effects. Thus

  12. Higher Maternal Protein Intake during Pregnancy Is Associated with Lower Cord Blood Concentrations of Insulin-like Growth Factor (IGF)-II, IGF Binding Protein 3, and Insulin, but Not IGF-I, in a Cohort of Women with High Protein Intake.

    Science.gov (United States)

    Switkowski, Karen M; Jacques, Paul F; Must, Aviva; Hivert, Marie-France; Fleisch, Abby; Gillman, Matthew W; Rifas-Shiman, Sheryl; Oken, Emily

    2017-07-01

    Background: Prenatal exposure to dietary protein may program growth-regulating hormones, consequently influencing early-life growth patterns and later risk of associated chronic diseases. The insulin-like growth factor (IGF) axis is of particular interest in this context given its influence on pre- and postnatal growth and its sensitivity to the early nutritional environment. Objective: Our objective was to examine associations of maternal protein intake during pregnancy with cord blood concentrations of IGF-I, IGF-II, IGF binding protein-3 (IGFBP-3), and insulin. Methods: We studied 938 mother-child pairs from early pregnancy through delivery in the Project Viva cohort. Using multivariable linear regression models adjusted for maternal race/ethnicity, education, income, smoking, parity, height, and gestational weight gain and for child sex, we examined associations of second-trimester maternal protein intake [grams per kilogram (weight before pregnancy) per day], as reported on a food frequency questionnaire, with IGF-I, IGF-II, IGFBP-3, and insulin concentrations in cord blood. We also examined how these associations may differ by child sex and parity. Results: Mothers were predominantly white (71%), college-educated (64%), and nonsmokers (67%). Mean ± SD protein intake was 1.35 ± 0.35 g ⋅ kg -1 ⋅ d -1 Each 1-SD increment in second-trimester protein intake corresponded to a change of -0.50 ng/mL (95% CI: -2.26, 1.26 ng/mL) in IGF-I and -0.91 μU/mL (95% CI: -1.45, -0.37 μU/mL) in insulin. Child sex and parity modified associations of maternal protein intake with IGF-II and IGFBP-3: protein intake was inversely associated with IGF-II in girls ( P -interaction = 0.04) and multiparous mothers ( P -interaction = 0.05), and with IGFBP-3 in multiparous mothers ( P -interaction = 0.04). Conclusions: In a cohort of pregnant women with relatively high mean protein intakes, higher intake was associated with lower concentrations of growth-promoting hormones in cord

  13. Silencing of Taxol-Sensitizer Genes in Cancer Cells: Lack of Sensitization Effects

    International Nuclear Information System (INIS)

    Huang, Shang-Lang; Chao, Chuck C.-K.

    2015-01-01

    A previous genome-wide screening analysis identified a panel of genes that sensitize the human non-small-cell lung carcinoma cell line NCI-H1155 to taxol. However, whether the identified genes sensitize other cancer cells to taxol has not been examined. Here, we silenced the taxol-sensitizer genes identified (acrbp, atp6v0d2, fgd4, hs6st2, psma6, and tubgcp2) in nine other cancer cell types (including lung, cervical, ovarian, and hepatocellular carcinoma cell lines) that showed reduced cell viability in the presence of a sub-lethal concentration of taxol. Surprisingly, none of the genes studied increased sensitivity to taxol in the tested panel of cell lines. As observed in H1155 cells, SKOV3 cells displayed induction of five of the six genes studied in response to a cell killing dose of taxol. The other cell types were much less responsive to taxol. Notably, four of the five inducible taxol-sensitizer genes tested (acrbp, atp6v0d2, psma6, and tubgcp2) were upregulated in a taxol-resistant ovarian cancer cell line. These results indicate that the previously identified taxol-sensitizer loci are not conserved genetic targets involved in inhibiting cell proliferation in response to taxol. Our findings also suggest that regulation of taxol-sensitizer genes by taxol may be critical for acquired cell resistance to the drug

  14. Silencing of Taxol-Sensitizer Genes in Cancer Cells: Lack of Sensitization Effects

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shang-Lang [Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Chao, Chuck C.-K., E-mail: cckchao@mail.cgu.edu.tw [Department of Biochemistry and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan (China); Department of Medical Research and Development, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan (China)

    2015-06-16

    A previous genome-wide screening analysis identified a panel of genes that sensitize the human non-small-cell lung carcinoma cell line NCI-H1155 to taxol. However, whether the identified genes sensitize other cancer cells to taxol has not been examined. Here, we silenced the taxol-sensitizer genes identified (acrbp, atp6v0d2, fgd4, hs6st2, psma6, and tubgcp2) in nine other cancer cell types (including lung, cervical, ovarian, and hepatocellular carcinoma cell lines) that showed reduced cell viability in the presence of a sub-lethal concentration of taxol. Surprisingly, none of the genes studied increased sensitivity to taxol in the tested panel of cell lines. As observed in H1155 cells, SKOV3 cells displayed induction of five of the six genes studied in response to a cell killing dose of taxol. The other cell types were much less responsive to taxol. Notably, four of the five inducible taxol-sensitizer genes tested (acrbp, atp6v0d2, psma6, and tubgcp2) were upregulated in a taxol-resistant ovarian cancer cell line. These results indicate that the previously identified taxol-sensitizer loci are not conserved genetic targets involved in inhibiting cell proliferation in response to taxol. Our findings also suggest that regulation of taxol-sensitizer genes by taxol may be critical for acquired cell resistance to the drug.

  15. A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

    KAUST Repository

    Ball, James M.; Davis, Nicola K. S.; Wilkinson, James D.; Kirkpatrick, James; Teuscher, Joë l; Gunning, Robert; Anderson, Harry L.; Snaith, Henry J.

    2012-01-01

    The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin

  16. Insulin-like growth factor I enhances proenkephalin synthesis and dopamine β-hydroxylase activity in adrenal chromaffin cells

    International Nuclear Information System (INIS)

    Wilson, S.P.

    1991-01-01

    Insulin-like growth factor I (IGF-I) increased both the contents of proenkephalin derived enkephalin-containing peptides and the activity of dopamine β-hydroxylase in bovine adrenal chromaffin cells. These increases in dopamine β-hydroxylase and enkephalin-containing peptides continued for at least 8 days. The half-maximal IGF-I concentration for these effects was ∼ 1 nM, with maximal effects observed at 10-30 nM. In contrast, insulin was 1,000-fold less potent. Pretreatment of chromaffin cells with IGF-I increased the rate of [ 35 S]proenkephalin synthesis 4-fold compared to untreated cells. Total protein synthesis increased only 1.5-fold under these conditions. These results suggest that IGF-I may be a normal regulator of chromaffin cell function

  17. Insulin-like growth factor I enhances proenkephalin synthesis and dopamine. beta. -hydroxylase activity in adrenal chromaffin cells

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, S.P. (Univ. of South Carolina School of Medicine, Columbia (USA))

    1991-01-01

    Insulin-like growth factor I (IGF-I) increased both the contents of proenkephalin derived enkephalin-containing peptides and the activity of dopamine {beta}-hydroxylase in bovine adrenal chromaffin cells. These increases in dopamine {beta}-hydroxylase and enkephalin-containing peptides continued for at least 8 days. The half-maximal IGF-I concentration for these effects was {approximately} 1 nM, with maximal effects observed at 10-30 nM. In contrast, insulin was 1,000-fold less potent. Pretreatment of chromaffin cells with IGF-I increased the rate of ({sup 35}S)proenkephalin synthesis 4-fold compared to untreated cells. Total protein synthesis increased only 1.5-fold under these conditions. These results suggest that IGF-I may be a normal regulator of chromaffin cell function.

  18. Insulin-like growth factor I has independent effects on bone matrix formation and cell replication

    International Nuclear Information System (INIS)

    Hock, J.M.; Centrella, M.; Canalis, E.

    1988-01-01

    The effects of insulin-like growth factor-I (IGF-I) and insulin on bone matrix synthesis and bone cell replication were studied in cultured 21-day-old fetal rat calvariae. Histomorphometry techniques were developed to measure the incorporation of [2,3- 3 H]proline and [methyl- 3 H]thymidine into bone matrix and bone cell nuclei, respectively, using autoradiographs of sagittal sections of calvariae cultured with IGF-I, insulin, or vehicle for up to 96 h. To confirm an effect on bone formation, IGF-I was also studied for its effects on [ 3 H]proline incorporation into collagenase-digestible protein (CDP) and noncollagen protein and on [ 3 H]thymidine incorporation into acid-precipitable material (DNA). IGF-I at 10(-9)-10(-7) M significantly increased the rate of bone matrix apposition and CDP after 24 h by 45-50% and increased cell labeling by 8-fold in the osteoprogenitor cell zone, by 4-fold in the osteoblast cell zone, and by 2-fold in the periosteal fibroblast zone. Insulin at 10(-9)-10(-6) M also increased matrix apposition rate and CDP by 40-50%, but increased cell labeling by 2-fold only at a concentration of 10(-7) M or higher and then only in the osteoprogenitor cell zone. When hydroxyurea was added to IGF-I-treated bones, the effects of IGF-I on DNA synthesis were abolished, but the increase in bone matrix apposition induced by IGF-I was only partly diminished. In conclusion, IGF-I stimulates matrix synthesis in calvariae, an effect that is partly, although not completely, dependent on its stimulatory effect on DNA synthesis

  19. Ruthenium Sensitizers and Their Applications in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Yuancheng Qin

    2012-01-01

    Full Text Available Dye-sensitized solar cells (DSSCs have attracted considerable attention in recent years due to the possibility of low-cost conversion of photovoltaic energy. The DSSCs-based ruthenium complexes as sensitizers show high efficiency and excellent stability, implying potential practical applications. This review focuses on recent advances in design and preparation of efficient ruthenium sensitizers and their applications in DSSCs, including thiocyanate ruthenium sensitizers and thiocyanate-free ruthenium sensitizers.

  20. Hypothalamic neurogenesis persists in the aging brain and is controlled by energy-sensing IGF-I pathway.

    Science.gov (United States)

    Chaker, Zayna; George, Caroline; Petrovska, Marija; Caron, Jean-Baptiste; Lacube, Philippe; Caillé, Isabelle; Holzenberger, Martin

    2016-05-01

    Hypothalamic tanycytes are specialized glial cells lining the third ventricle. They are recently identified as adult stem and/or progenitor cells, able to self-renew and give rise to new neurons postnatally. However, the long-term neurogenic potential of tanycytes and the pathways regulating lifelong cell replacement in the adult hypothalamus are largely unexplored. Using inducible nestin-CreER(T2) for conditional mutagenesis, we performed lineage tracing of adult hypothalamic stem and/or progenitor cells (HySC) and demonstrated that new neurons continue to be born throughout adult life. This neurogenesis was targeted to numerous hypothalamic nuclei and produced different types of neurons in the dorsal periventricular regions. Some adult-born neurons integrated the median eminence and arcuate nucleus during aging and produced growth hormone releasing hormone. We showed that adult hypothalamic neurogenesis was tightly controlled by insulin-like growth factors (IGF). Knockout of IGF-1 receptor from hypothalamic stem and/or progenitor cells increased neuronal production and enhanced α-tanycyte self-renewal, preserving this stem cell-like population from age-related attrition. Our data indicate that adult hypothalamus retains the capacity of cell renewal, and thus, a substantial degree of structural plasticity throughout lifespan. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. [EFECTOS NEUROENDOCRINOS DE INSULINA, IGF-I Y LEPTINA SOBRE LA SECRECIÓN DE HORMONA LIBERADORA DE GONADOTROPINAS (GnRH

    Directory of Open Access Journals (Sweden)

    Ana Maria Rosales-Torres

    2011-10-01

    Full Text Available El balance energético del individuo determina en gran medida su eficiencia reproductiva. Bajo condiciones de balance negativo de energía, en la mayoría de los mamíferos, hay una reducción en la síntesis de hormona liberadora de gonadotropinas (GnRH, lo cual disminuye la actividad del eje hipotálamo-hipófisis-gónadas. Cuando el balance energético es revertido, el hipotálamo puede monitorear este cambio y restablecer la secreción de GnRH. La Insulina, el Factor de Crecimiento similar a la Insulina I (IGF-I y Leptina parecen ser los principales mensajeros que informan al hipotálamo sobre el estado energético del animal puesto que las concentraciones periféricas de estas hormonas en situaciones energéticas negativas o positivas, se han asociado con los cambios en la secreción de GnRH. En la presente revisión se muestra como IGF-I actúa directamente sobre neuronas secretoras de GnRH, afectando su síntesis, en tanto que insulina y leptina actúan sobre neuronas en el núcleo arcuato, las cuales hacen sinapsis con neuronas GnRH en el área preóptica medial. Sobre neuronas productoras de neuropéptido Y (NPY insulina y leptina reducen su expresión y por lo tanto el efecto negativo del NPY sobre neuronas GnRH. En cambio insulina y leptina estimulan la síntesis de péptido similar a la galanina (GLAP y propiomelanocortina (POMC. Tanto GALP como los metabolitos de POMC (hormona estimulante de melanocitos principalmente incrementan la síntesis de GnRH. Finalmente, la leptina, incrementa la expresión de kispeptina en neuronas del núcleo ARC. Kispeptina por su parte también tiene un efecto positivo sobre la síntesis y secreción de GnRH.

  2. The impact of pegvisomant treatment on substrate metabolism and insulin sensitivity in patients with acromegaly

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Rune; Møller, Niels; Schmitz, Ole

    2007-01-01

    CONTEXT: Pegvisomant is a specific GH receptor antagonist that is able to normalize serum IGF-I concentrations in most patients with acromegaly. The impact of pegvisomant on insulin sensitivity and substrate metabolism is less well described. PATIENTS AND METHODS: We assessed basal and insulin......-stimulated (euglycemic clamp) substrate metabolism in seven patients with active acromegaly before and after 4-wk pegvisomant treatment (15 mg/d) in an open design. RESULTS: After pegvisomant, IGF-I decreased, whereas GH increased (IGF-I, 621 +/- 82 vs. 247 +/- 33 microg/liter, P = 0.02; GH, 5.3 +/- 1.5 vs. 10.8 +/- 3...... vs. 1563 +/- 101 kcal/24 h, P = 0.03), but the rate of lipid oxidation did not change significantly. CONCLUSIONS: 1) Pegvisomant treatment for 4 wk improves peripheral and hepatic insulin sensitivity in acromegaly. 2) This is associated with a decrease in resting energy expenditure, whereas free...

  3. Pre-treatment growth and IGF-I deficiency as main predictors of response to growth hormone therapy in neural models

    Directory of Open Access Journals (Sweden)

    Urszula Smyczyn´ska

    2018-01-01

    Full Text Available Mathematical models have been applied in prediction of growth hormone treatment effectiveness in children since the end of 1990s. Usually they were multiple linear regression models; however, there are also examples derived by empirical non-linear methods. Proposed solution consists in application of machine learning technique – artificial neural networks – to analyse this problem. This new methodology, contrary to previous ones, allows detection of both linear and non-linear dependencies without assuming their character a priori. The aims of this work included: development of models predicting separately growth during 1st year of treatment and final height as well as identification of important predictors and in-depth analysis of their influence on treatment’s effectiveness. The models were derived on the basis of clinical data of 272 patients treated for at least 1 year, 133 of whom have already attained final height. Starting from models containing 17 and 20 potential predictors, respectively for 1st year and final height model, we were able to reduce their number to 9 and 10. Basing on the final models, IGF-I concentration and earlier growth were indicated as belonging to most important predictors of response to GH therapy, while results of GH secretion tests were automatically excluded as insignificant. Moreover, majority of the dependencies were observed to be non-linear, thus using neural networks seems to be reasonable approach despite it being more complex than previously applied methods.

  4. Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

    Science.gov (United States)

    Martins, Y S; Melo, R M C; Campos-Junior, P H A; Santos, J C E; Luz, R K; Rizzo, E; Bazzoli, N

    2014-06-01

    The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. IRS-1 acts as an endocytic regulator of IGF-I receptor to facilitate sustained IGF signaling.

    Science.gov (United States)

    Yoneyama, Yosuke; Lanzerstorfer, Peter; Niwa, Hideaki; Umehara, Takashi; Shibano, Takashi; Yokoyama, Shigeyuki; Chida, Kazuhiro; Weghuber, Julian; Hakuno, Fumihiko; Takahashi, Shin-Ichiro

    2018-04-11

    Insulin-like growth factor-I receptor (IGF-IR) preferentially regulates the long-term IGF activities including growth and metabolism. Kinetics of ligand-dependent IGF-IR endocytosis determines how IGF induces such downstream signaling outputs. Here, we find that the insulin receptor substrate (IRS)-1 modulates how long ligand-activated IGF-IR remains at the cell surface before undergoing endocytosis in mammalian cells. IRS-1 interacts with the clathrin adaptor complex AP2. IRS-1, but not an AP2-binding-deficient mutant, delays AP2-mediated IGF-IR endocytosis after the ligand stimulation. Mechanistically, IRS-1 inhibits the recruitment of IGF-IR into clathrin-coated structures; for this reason, IGF-IR avoids rapid endocytosis and prolongs its activity on the cell surface. Accelerating IGF-IR endocytosis via IRS-1 depletion induces the shift from sustained to transient Akt activation and augments FoxO-mediated transcription. Our study establishes a new role for IRS-1 as an endocytic regulator of IGF-IR that ensures sustained IGF bioactivity, independent of its classic role as an adaptor in IGF-IR signaling. © 2018, Yoneyama et al.

  6. Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines

    International Nuclear Information System (INIS)

    Hata, H.; Numata, M.; Tohda, H.; Yasui, A.; Oikawa, A.

    1991-01-01

    1-[(4-Amino-2-methylpyrimidin-5-yl)methyl]-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar to that of the parental cell lines CHO9. One mutant (UVS1) was cross-sensitive to UV and complemented the UV sensitivity of all Chinese hamster cell lines of 7 established complementation groups. Since UV-induced unscheduled DNA synthesis was very low, a new locus related to excision repair is thought to be defective in this cell line. Another ACNU-sensitive mutant, CNU1, was slightly more sensitive to UV than the parent cell line. CNU1 was cross-sensitive to 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and slightly more sensitive to mitomycin C. No increased accumulation of ACNU and a low level of UV-induced unscheduled DNA synthesis in this cell as compared with the parental cell line suggest that there is abnormality in a repair response of this mutant cell to some types of DNA cross-links

  7. Cytokines and growth factors which regulate bone cell function

    Science.gov (United States)

    Seino, Yoshiki

    Everybody knows that growth factors are most important in making bone. Hormones enhance bone formation from a long distance. Growth factors promote bone formation as an autocrine or paracrine factor in nearby bone. BMP-2 through BMP-8 are in the TGF-β family. BMP makes bone by enchondral ossification. In bone, IGF-II is most abundant, second, TGF-β, and third IGF-I. TGF-β enhances bone formation mainly by intramembranous ossification in vivo. TGF-β affects both cell proliferation and differentiation, however, TGF-β mainly enhances bone formation by intramembranous ossification. Interestingly, TGF-β is increased by estrogen(E 2), androgen, vitamin D, TGF-β and FGF. IGF-I and IGF-II also enhance bone formation. At present it remains unclear why IGF-I is more active in bone formation than IGF-II, although IGF-II is more abundant in bone compared to IGF-I. However, if only type I receptor signal transduction promotes bone formation, the strong activity of IGF-I in bone formation is understandable. GH, PTH and E 2 promotes IGF-I production. Recent data suggest that hormones containing vitamin D or E 2 enhance bone formation through growth factors. Therefore, growth factors are the key to clarifying the mechanism of bone formation.

  8. Keynote address: hypoxic cell sensitizers: clinical developments

    International Nuclear Information System (INIS)

    Dische, S.

    1989-01-01

    Tumors having small islands of cells should be radiosensitive, and those having large masses, radioresistant. This was found to be the case and there is a ready explanation for this: the outside cells are close to blood vessels and will thus be well supplied with oxygen, while the inside cells are not well placed in this respect. Now it is known that cells well supplied with oxygen are radiosensitive, compared to the same cells deprived of oxygen; it is therefore likely that for this reason, variation in blood supply, that the outside cells are more easily destroyed than those within.''29 references

  9. Photoelectrode nanostructure dye-sensitized solar cell | Kimpa ...

    African Journals Online (AJOL)

    This study used carica papaya (pawpaw leaf) extracts as natural organic dye for dye sensitized solar cell (DSSC). Pawpaw leaf extract is rich in chlorophyll and was extracted using ethanol as the extracting solvent and serve as the sensitizer for DSSC. The specialty of the DSSC relative to other types of solar cells is the use ...

  10. Effects of long term feeding diets differing in protein source and pre-slaughter starvation on biometry, qualitative traits and liver IGF-I expression in large rainbow trout

    Directory of Open Access Journals (Sweden)

    Emilio Tibaldi

    2010-01-01

    Full Text Available The effects of feeding two complete extruded diets differing in protein source (fish meal-FM vs. vegetable proteins-VP over 30 weeks and subsequent 30 days of starvation on biometry, fillet composition and liver IGF-I mRNA were studied in large rainbow trout. At the end of the feeding period, the dietary protein source little affected major biometry traits, dressing out yields and overall adiposity (P>0.05 but fish given the VP diet resulted in higher content of PUFA n-6 fatty acids in mus- cle (0.46 vs. 0.22 g/100g fillet, P0.05 and of all fatty acids in fillet (P<0.05, except DHA. Liver IGF-I mRNA content was little affected by the test diet and starvation.

  11. Effect of recombinant human insulin-like growth factor-I on progression of ALS. A placebo-controlled study. The North America ALS/IGF-I Study Group.

    Science.gov (United States)

    Lai, E C; Felice, K J; Festoff, B W; Gawel, M J; Gelinas, D F; Kratz, R; Murphy, M F; Natter, H M; Norris, F H; Rudnicki, S A

    1997-12-01

    The objective of this study was to investigate the safety and efficacy of recombinant human insulinlike growth factor-I (rhIGF-I) in the treatment of sporadic ALS. A double-blind, placebo-controlled, randomized study of 266 patients was conducted at eight centers in North America. Placebo or rhIGF-I (0.05 mg/kg/day or 0.10 mg/kg/day) was administered for 9 months. The primary outcome measure was disease symptom progression, assessed by the rate of change (per patient slope) in the Appel ALS rating scale total score. The Sickness Impact Profile (SIP), a patient-perceived, health-related quality of life assessment, was a secondary outcome variable. Progression of functional impairment in patients receiving high-dose (0.10 mg/kg/day) rhIGF-I was 26% slower than in patients receiving placebo (p = 0.01). The high-dose treatment group was less likely to terminate the study due to protocol-defined markers of disease symptom progression, and members in this group exhibited a slower decline in quality of life, as assessed by the SIP. Patients receiving 0.05 mg/kg/day of rhIGF-I exhibited trends similar to those associated with high-dose treatment, suggesting a dose-dependent response. The incidence of clinically significant adverse experiences was comparable among the three treatment groups. Recombinant human insulin-like growth factor-I slowed the progression of functional impairment and the decline in health-related quality of life in patients with ALS with no medically important adverse effects.

  12. Regulation of hypoxia-inducible factor-1α (HIF-1α expression by interleukin-1β (IL-1 β, insulin-like growth factors I (IGF-I and II (IGF-II in human osteoarthritic chondrocytes

    Directory of Open Access Journals (Sweden)

    Angelica Rossi Sartori-Cintra

    2012-01-01

    Full Text Available OBJECTIVE: Hypoxia-inducible factor 1 alpha regulates genes related to cellular survival under hypoxia. This factor is present in osteroarthritic chondrocytes, and cytokines, such as interleukin-1 beta, participate in the pathogenesis of osteoarthritis, thereby increasing the activities of proteolytic enzymes, such as matrix metalloproteinases, and accelerating cartilage destruction. We hypothesize that Hypoxia Inducible Factor-1 alpha (HIF-1α can regulate cytokines (catabolic action and/or growth factors (anabolic action in osteoarthritis. The purpose of this study was to investigate the modulation of HIF-1α in human osteoarthritic chondrocytes by interleukin-1 beta (IL-1β and insulin-like growth factors I (IGF-I and II (IGF-II and to determine the involvement of the phosphatidylinositol-3kinase (PI-3K pathway in this process. METHODS: Human osteroarthritic chondrocytes were stimulated with IL-1β, IGF-I and IGF-II and LY294002, a specific inhibitor of PI-3K. Nuclear protein levels and gene expression were analyzed by western blot and quantitative reverse transcription-polymerase chain reaction analyses, respectively. RESULTS: HIF-1α expression was upregulated by IL-1β at the protein level but not at the gene level. IGF-I treatment resulted in increases in both the protein and mRNA levels of HIF-1α , whereas IGF-II had no effect on its expression. However, all of these stimuli exploited the PI-3K pathway. CONCLUSION: IL-1β upregulated the levels of HIF-1α protein post-transcriptionally, whereas IGF-I increased HIF-1α at the transcript level. In contrast, IGF-II did not affect the protein or gene expression levels of HIF-1α . Furthermore, all of the tested stimuli exploited the PI-3K pathway to some degree. Based on these findings, we are able to suggest that Hypoxia inducible Factor-1 exhibits protective activity in chondrocytes during osteoarthritis.

  13. EXPRESSION OF GROWTH HORMONE (PhGH GENE AND ANALYSIS OF INSULINE-LIKE GROWTH FACTOR I (IGF-I PRODUCTION IN AFRICAN CATFISH (Clarias gariepinus TRANSGENIC F-1

    Directory of Open Access Journals (Sweden)

    Huria Marnis

    2013-12-01

    Full Text Available We have previously produced F-1 transgenic of African catfish from crosses between founder transgenic female and non transgenic male. The aim of this study was to evaluate distribution and expression PhGH growth hormone gene transgenic African catfish organs and to measure the concentration of IGF-I in plasma. Transgene was detected using the PCR method in various organs, namely pituitary, brain, liver, heart, spleen, kidney, intestine, stomach, muscle, gill, and eye. Transgene expression levels were analyzed using the method of quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR. Plasma samples were analyzed for Insuline-like Growth Factor (IGF-I using Enzyme Linked Immunosorbent Assay (ELISA method. The results showed that the PhGH was detected and expressed in all organs of the transgenic African catfish (F-1. Liver exhibited the highest level of PhGH mRNA (23 x 106 copies. The plasma IGF-I levels in transgenic individuals were not significant than non transgenic. The higher level of exogenous PhGH gene expression may not represent the production of IGF-1.

  14. Fetal programming of insulin-like growth factor (IGF)-I and IGF-binding protein-3: evidence for an altered response to undernutrition in late gestation following exposure to periconceptual undernutrition in the sheep.

    Science.gov (United States)

    Gallaher, B W; Breier, B H; Keven, C L; Harding, J E; Gluckman, P D

    1998-12-01

    It has been demonstrated in several animal models that undernutrition in utero has significant long lasting effects on subsequent fetal and postnatal development. To address the hypothesis that the insulin-like growth factors (IGFs) may mediate such effects, our study examined whether a period of periconceptual maternal undernutrition could have a lasting influence on the IGF axis in the fetal sheep. Ewes were either allowed to feed ad libitum or kept undernourished from day 60 prior to mating until day 30 after conception, and then both groups were allowed to feed ad libitum. These groups were further divided at day 105 of gestation, either being fed ad libitum or undernourished until day 115 of gestation. Fetal and maternal blood samples were obtained at both day 105 and 115 of gestation. We describe the development of a specific homologous RIA to measure ovine IGF-binding protein-3 (IGFBP-3) in fetal and maternal sheep plasma. Fetal plasma IGFBP-3 and IGF-I concentrations were significantly (Pfetal plasma IGFBP-2 levels were unchanged. The degree of reduction in fetal plasma IGFBP-3 and IGF-I between day 105 and 115 of gestation as a response to acute maternal undernutrition was significantly greater (Pfetal plasma IGFBP-3 concentrations were not the result of increased proteolytic activity. These results suggest that exposure to maternal periconceptual undernutrition reprograms IGFBP-3 and IGF-I regulation in the developing sheep fetus, altering its response to undernutrition in late gestation.

  15. Head circumference in untreated and IGF-I treated patients with Laron syndrome: comparison with untreated and hGH-treated children with isolated growth hormone deficiency.

    Science.gov (United States)

    Laron, Zvi; Iluz, Moshe; Kauli, Rivka

    2012-04-01

    Head circumference (HC) is a simple and practical measure of brain size, development and longitudinal measurements of the HC in childhood are an index of brain growth. To determine the effects of long IGF-I deficiency and treatment on HC in patients with Laron syndrome (LS). 20 untreated adult LS patients, aged 48.4±11.2 years and 13 LS patients treated between ages of 5.6±4 to 11.3±3 years were studied. 15 patients with congenital IGHD treated between age 6.1±4 and 13±4 by hGH served as controls. HC was expressed as standard deviation (SD) and Ht as SDS. HC was measured and plotted on Nellhaus charts. Linear height (Ht) was measured by a Harpenden Stadiometer. The mean HC deficit of the adult untreated LS males was -2.9±0.6 SD compared to a Ht deficit of -7.0±1.7 SDS. The HC of the LS adult females was -3.6±1 SD compared to a Ht SDS of -6.9±1.5 (pdeficit decreased only by 1.5 SDS. hGH treatment of cIGHD children increased the HC from -2.0±1.8 to 0.3±1.2 SD and the Ht SDS from -4.8±1.6 to 1.6±1.0. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Sensitivity Analysis of Centralized Dynamic Cell Selection

    DEFF Research Database (Denmark)

    Lopez, Victor Fernandez; Alvarez, Beatriz Soret; Pedersen, Klaus I.

    2016-01-01

    and a suboptimal optimization algorithm that nearly achieves the performance of the optimal Hungarian assignment. Moreover, an exhaustive sensitivity analysis with different network and traffic configurations is carried out in order to understand what conditions are more appropriate for the use of the proposed...

  17. NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method

    International Nuclear Information System (INIS)

    Ogbomo, Henry; Hahn, Anke; Geiler, Janina; Michaelis, Martin; Doerr, Hans Wilhelm; Cinatl, Jindrich

    2006-01-01

    The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients

  18. Radiation sensitivity of human lung cancer cell lines

    International Nuclear Information System (INIS)

    Carmichael, J.; Degraff, W.G.; Gamson, J.; Russo, G.; Mitchell, J.B.; Gazdar, A.F.; Minna, J.D.; Levitt, M.L.

    1989-01-01

    X-Ray survival curves were determined using a panel of 17 human lung cancer cell lines, with emphasis on non-small cell lung cancer (NSCLC). In contrast to classic small cell lung cancer (SCLC) cell lines, NSCLC cell lines were generally less sensitive to radiation as evidenced by higher radiation survival curve extrapolation numbers, surviving fraction values following a 2Gy dose (SF2) and the mean inactivation dose values (D) values. The spectrum of in vitro radiation responses observed was similar to that expected in clinical practice, although mesothelioma was unexpectedly sensitive in vitro. Differences in radiosensitivity were best distinguished by comparison of SF2 values. Some NSCLC lines were relatively sensitive, and in view of this demonstrable variability in radiation sensitivity, the SF2 value may be useful for in vitro predictive assay testing of clinical specimens. (author)

  19. X-ray sensitivity of somatic cell hybrids

    International Nuclear Information System (INIS)

    Zampetti-Bosseler, F.; Heilporn, V.; Lievens, A.; Limbosch, S.

    1976-01-01

    Different somatic cell hybrids have been studied as a function of their x-ray survival and karyotypic properties. Hybrids between x-ray-sensitive mouse lymphoma cells and mouse fibroblasts, retaining a large proportion of both parental chromosomes, were much more resistant to irradiation than either of the parental cells. On the other hand, hybrids between sensitive mouse lymphoma cells and hamster fibroblasts which also retained a relatively high number of chromosomes from both parents had a sensitivity intermediate between the sensitivities of the parental cell lines. Finally, hybrids between mouse fibroblasts and hamster fibroblasts carrying at least one hamster genome and less than one mouse genome resembled the hamster parent with respect to survival capactity. The significance of these results is discussed

  20. GABA sensitivity of spectrally classified horizontal cells in goldfish retina

    NARCIS (Netherlands)

    Verweij, J.; Kamermans, M.; Negishi, K.; Spekreijse, H.

    1998-01-01

    We studied the GABA sensitivity of horizontal cells in the isolated goldfish retina. After the glutamatergic input to the horizontal cells was blocked with DNQX, GABA depolarized the monophasic and biphasic horizontal cells. The pharmacology of these GABA-induced depolarizations was tested with the

  1. Mechanisms underlying KCNQ1channel cell volume sensitivity

    DEFF Research Database (Denmark)

    Hammami, Sofia

    Cells are constantly exposed to changes in cell volume during cell metabolism, nutrient uptake, cell proliferation, cell migration and salt and water transport. In order to cope with these perturbations, potassium channels in line with chloride channels have been shown to be likely contributors...... to the process of cell volume adjustments. A great diversity of potassium channels being members of either the 6TM, 4 TM or 2 TM K+ channel gene family have been shown to be strictly regulated by small, fast changes in cell volume. However, the precise mechanism underlying the K+ channel sensitivity to cell...... volume alterations is not yet fully understood. The KCNQ1 channel belonging to the voltage gated KCNQ family is considered a precise sensor of volume changes. The goal of this thesis was to elucidate the mechanism that induces cell volume sensitivity. Until now, a number of investigators have implicitly...

  2. Sensitivity of Dendritic Cells to Microenvironment Signals

    Directory of Open Access Journals (Sweden)

    Juliana Maria Motta

    2016-01-01

    Full Text Available Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.

  3. The Distinctive Sensitivity to Microgravity of Immune Cell Subpopulations

    Science.gov (United States)

    Chen, Hui; Luo, Haiying; Liu, Jing; Wang, Peng; Dong, Dandan; Shang, Peng; Zhao, Yong

    2015-11-01

    Immune dysfunction in astronauts is well documented after spaceflights. Microgravity is one of the key factors directly suppressing the function of immune system. However, it is unclear which subpopulations of immune cells including innate and adaptive immune cells are more sensitive to microgravity We herein investigated the direct effects of modeled microgravity (MMg) on different immune cells in vitro. Mouse splenocytes, thymocytes and bone marrow cells were exposed to MMg for 16 hrs. The survival and the phenotypes of different subsets of immune cells including CD4+T cells, CD8+T cells, CD4+Foxp3+ regulatory T cells (Treg), B cells, monocytes/macrophages, dendritic cells (DCs), natural killer cells (NK) were determined by flow cytometry. After splenocytes were cultured under MMg for 16h, the cell frequency and total numbers of monocytes, macrophages and CD4+Foxp3+T cells were significantly decreased more than 70 %. MMg significantly decreased the cell numbers of CD8+ T cells, B cells and neutrophils in splenocytes. The cell numbers of CD4+T cells and NK cells were unchanged significantly when splenocytes were cultured under MMg compared with controls. However, MMg significantly increased the ratio of mature neutrophils to immature neutrophils in bone marrow and the cell number of DCs in splenocytes. Based on the cell survival ability, monocytes, macrophages and CD4+Foxp3+Treg cells are most sensitive to microgravity; CD4+T cells and NK cells are resistant to microgravity; CD8+T cells and neutrophils are impacted by short term microgravity exposure. Microgravity promoted the maturation of neutrophils and development of DCs in vitro. The present studies offered new insights on the direct effects of MMg on the survival and homeostasis of immune cell subsets.

  4. Research Progress of Photoanodes for Quantum Dot Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    LI Zhi-min

    2017-08-01

    Full Text Available This paper presents the development status and tendency of quantum dot sensitized solar cells. Photoanode research progress and its related technologies are analyzed in detail from the three ways of semiconductor thin films, quantum dot co-sensitization and quantum dot doping, deriving from the approach that the conversion efficiency can be improved by photoanode modification for quantum dot sensitized solar cells. According to the key factors which restrict the cell efficiency, the promising future development of quantum dot sensitized solar cells is proposed,for example,optimizing further the compositions and structures of semiconductor thin films for the photoanodes, exploring new quantum dots with broadband absorption and developing high efficient techniques of interface modification.

  5. Metal Complex Dyes for Dye-Sensitized Solar Cells: Recent ...

    Indian Academy of Sciences (India)

    interests are in coding theory, error-correction in networks and wireless communication.“ Ruthenium ..... Calculate power conversion efficiency by using the formula: 100 ... Molar Extinction Coefficient Charge-Transfer Sensitizers for Solar Cell.

  6. Novel nanostructures for next generation dye-sensitized solar cells

    KAUST Repository

    Té treault, Nicolas; Grä tzel, Michael

    2012-01-01

    Herein, we review our latest advancements in nanostructured photoanodes for next generation photovoltaics in general and dye-sensitized solar cells in particular. Bottom-up self-assembly techniques are developed to fabricate large-area 3D

  7. Sparging - shear sensitivity of animal cells

    NARCIS (Netherlands)

    Pol, van der L.A.

    1998-01-01

    Biopharmaceuticals are increasingly produced by modern biotechnological techniques. The in-vitro culture of animal cells in stirred tanks is one of the feasible systems, especially for proteins that require specific post-tanslational modifications to evoke a desired respons in patients.

  8. Characterization of ibrutinib-sensitive and -resistant mantle lymphoma cells.

    Science.gov (United States)

    Ma, Jiao; Lu, Pin; Guo, Ailin; Cheng, Shuhua; Zong, Hongliang; Martin, Peter; Coleman, Morton; Wang, Y Lynn

    2014-09-01

    Ibrutinib inhibits Bruton tyrosine kinase (BTK), a key component of early B-cell receptor (BCR) signalling pathways. A multicentre phase 2 trial of ibrutinib in patients with relapsed/refractory mantle cell lymphoma (MCL) demonstrated a remarkable response rate. However, approximately one-third of patients have primary resistance to the drug while other patients appear to lose response and develop secondary resistance. Understanding the molecular mechanisms underlying ibrutinib sensitivity is of paramount importance. In this study, we investigated cell lines and primary MCL cells that display differential sensitivity to ibrutinib. We found that the primary cells display a higher BTK activity than normal B cells and MCL cells show differential sensitivity to BTK inhibition. Genetic knockdown of BTK inhibits the growth, survival and proliferation of ibrutinib-sensitive but not resistant MCL cell lines, suggesting that ibrutinib acts through BTK to produce its anti-tumour activities. Interestingly, inhibition of ERK1/2 and AKT, but not BTK phosphorylation per se, correlates well with cellular response to BTK inhibition in cell lines as well as in primary tumours. Our study suggests that, to prevent primary resistance or to overcome secondary resistance to BTK inhibition, a combinatory strategy that targets multiple components or multiple pathways may represent the most effective approach. © 2014 John Wiley & Sons Ltd.

  9. Effect of troglitazone on radiation sensitivity in cervix cancer cells

    International Nuclear Information System (INIS)

    An, Zheng Zhe; Liu, Xian Guang; Song, Hye Jin; Choi, Chi Hwan; Kim, Won Dong; Park, Woo Yoon; Yu, Jae Ran

    2012-01-01

    Troglitazone (TRO) is a peroxisome proliferator-activated receptor γ (PPARγ ) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu 2+ /Zn 2+ -superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 μM of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. By 5 μM TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0- G1 phase cells were increased in HeLa and Me180 by 5 μM TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 μM TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 μM TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalasemediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPAR γ expression level.

  10. Saw palmetto extract suppresses insulin-like growth factor-I signaling and induces stress-activated protein kinase/c-Jun N-terminal kinase phosphorylation in human prostate epithelial cells.

    Science.gov (United States)

    Wadsworth, Teri L; Carroll, Julie M; Mallinson, Rebecca A; Roberts, Charles T; Roselli, Charles E

    2004-07-01

    A common alternative therapy for benign prostatic hyperplasia (BPH) is the extract from the fruit of saw palmetto (SPE). BPH is caused by nonmalignant growth of epithelial and stromal elements of the prostate. IGF action is important for prostate growth and development, and changes in the IGF system have been documented in BPH tissues. The main signaling pathways activated by the binding of IGF-I to the IGF-I receptor (IGF-IR) are the ERK arm of the MAPK cascade and the phosphoinositol-3-kinase (PI3K)/protein kinase B (PKB/Akt) cascade. We tested the hypothesis that SPE suppresses growth and induces apoptosis in the P69 prostate epithelial cell line by inhibiting IGF-I signaling. Treatment with 150 microg/ml SPE for 24 h decreased IGF-I-induced proliferation of P69 cells and induced cleavage of the enzyme poly(ADP-ribose)polymerase (PARP), an index of apoptosis. Treatment of serum-starved P69 cells with 150 microg/ml SPE for 6 h reduced IGF-I-induced phosphorylation of Akt (assessed by Western blot) and Akt activity (assessed by an Akt kinase assay). Western blot analysis showed that SPE reduced IGF-I-induced phosphorylation of the adapter protein insulin receptor substrate-1 and decreased downstream effects of Akt activation, including increased cyclin D1 levels and phosphorylation of glycogen synthase kinase-3 and p70(s6k). There was no effect on IGF-I-induced phosphorylation of MAPK, IGF-IR, or Shc. Treatment of starved cells with SPE alone induced phosphorylation the proapoptotic protein JNK. SPE treatment may relieve symptoms of BPH, in part, by inhibiting specific components of the IGF-I signaling pathway and inducing JNK activation, thus mediating antiproliferative and proapoptotic effects on prostate epithelia.

  11. Bovine ocular squamous cell carcinoma: UV sensitivity in lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, M.F.; Jennings, P.A.; Hughes, D.J. (Queensland Univ., Brisbane (Australia))

    1982-05-01

    Increased sensitivity to UV light has been demonstrated in Phytohaemagglutinin stimulated lymphocytes from normal and tumour-bearing Hereford cattle when compared to lymphocytes from other breeds. Trypan blue exclusion and inhibition of DNA synthesis were used to determine cell viability. The results obtained from time course and radiation dose experiments demonstrate biphasic survival kinetics. This is indicative of at least two separate cell populations, exhibiting differential sensitivity to UV. The increased sensitivity to UV observed in Herefords may reflect a general sensitivity to UV or alternatively a different cellular constitution in the mitogen stimulated cultures. DNA repair synthesis, measured in the presence of hydroxyurea, was of similar levels in cell cultures from Herefords and one of the control breeds.

  12. Bovine ocular squamous cell carcinoma: UV sensitivity in lymphocytes

    International Nuclear Information System (INIS)

    Lavin, M.F.; Jennings, P.A.; Hughes, D.J.

    1982-01-01

    Increased sensitivity to UV light has been demonstrated in Phytohaemagglutinin stimulated lymphocytes from normal and tumour-bearing Hereford cattle when compared to lymphocytes from other breeds. Trypan blue exclusion and inhibition of DNA synthesis were used to determine cell viability. The results obtained from time course and radiation dose experiments demonstrate biphasic survival kinetics. This is indicative of at least two separate cell populations, exhibiting differential sensitivity to UV. The increased sensitivity to UV observed in Herefords may reflect a general sensitivity to UV or alternatively a different cellular constitution in the mitogen stimulated cultures. DNA repair synthesis, measured in the presence of hydroxyurea, was of similar levels in cell cultures from Herefords and one of the control breeds. (author)

  13. Osmotically sensitive renin release from permeabilized juxtaglomerular cells

    DEFF Research Database (Denmark)

    Jensen, B L; Skøtt, O

    1993-01-01

    Renin secretion from juxtaglomerular (JG) cells is sensitive to external osmolality in a way that has been suggested to depend either on cellular volume or on effects on secretory granules. To distinguish between these possibilities, a technique for permeabilization of JG cell membranes was devel...

  14. Cell sensitivity to irradiation and DNA repair processes

    International Nuclear Information System (INIS)

    Kozubek, S.; Krasavin, E.A.

    1984-01-01

    A new model of oxygen effect realisation is proposed for E.coli cells. The model explains differencies in oxygen enhancement ratio (OER) between wild type cells and repair deficient mutants. These differencies are logically linked to corresponding defects in repair systems. A quantitative analysis has been performed. The dependence of OER and cell sensitivity on the properties of cultivation medium is considered, too. Decreasing OER and increasing sensitivity in poor conditions are explained as the consequence of the shift of repair capacity from slow to fast repair system

  15. Common elements in interleukin 4 and insulin signaling pathways in factor-dependent hematopoietic cells.

    Science.gov (United States)

    Wang, L M; Keegan, A D; Li, W; Lienhard, G E; Pacini, S; Gutkind, J S; Myers, M G; Sun, X J; White, M F; Aaronson, S A

    1993-05-01

    Interleukin 4 (IL-4), insulin, and insulin-like growth factor I (IGF-I) efficiently induced DNA synthesis in the IL-3-dependent murine myeloid cell lines FDC-P1 and FDC-P2. Although these factors could not individually sustain long-term growth of these lines, a combination of IL-4 with either insulin or IGF-I did support continuous growth. The principal tyrosine-phosphorylated substrate observed in FDC cells stimulated with IL-4, previously designated 4PS, was of the same size (170 kDa) as the major substrate phosphorylated in response to insulin or IGF-I. These substrates had phosphopeptides of the same size when analyzed by digestion with Staphylococcus aureus V8 protease, and each tightly associated with the 85-kDa component of phosphatidylinositol 3-kinase after factor stimulation. IRS-1, the principal substrate phosphorylated in response to insulin or IGF-I stimulation in nonhematopoietic cells, is similar in size to 4PS. However, anti-IRS-1 antibodies failed to efficiently precipitate 4PS, and some phosphopeptides generated by V8 protease digestion of IRS-1 were distinct in size from the phosphopeptides of 4PS. Nevertheless, IL-4, insulin, and IGF-I were capable of stimulating tyrosine phosphorylation of IRS-1 in FDC cells that expressed this substrate as a result of transfection. These findings indicate that (i) IL-4, insulin, and IGF-I use signal transduction pathways in FDC lines that have at least one major feature in common, the rapid tyrosine phosphorylation of 4PS, and (ii) insulin and IGF-I stimulation of hematopoietic cell lines leads to the phosphorylation of a substrate that may be related to but is not identical to IRS-1.

  16. Fabrication and Characterization of Dye-Sensitized Solar Cells

    OpenAIRE

    Mohamed FATHALLAH; Ahmed TORCHANI; Rached GHARBI

    2014-01-01

    Dye-sensitized solar cell (DSSC) constitutes a real revolution in the conversion of solar energy into electricity after 40 years of the invention of silicon solar cells. The working mechanism is based on a photoelectrochemical system, similar to the photosynthesis in plant leaves. The efficiencies of the DSSC are high as those obtained from amorphous silicon solar cells (10-11 %) and intensive efforts are done in different directions to improve this efficiency.

  17. Fabrication and Characterization of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mohamed FATHALLAH

    2014-05-01

    Full Text Available Dye-sensitized solar cell (DSSC constitutes a real revolution in the conversion of solar energy into electricity after 40 years of the invention of silicon solar cells. The working mechanism is based on a photoelectrochemical system, similar to the photosynthesis in plant leaves. The efficiencies of the DSSC are high as those obtained from amorphous silicon solar cells (10-11 % and intensive efforts are done in different directions to improve this efficiency.

  18. Serum insulin-like growth factor (IGF)-I and IGF binding protein-3 in relation to terminal duct lobular unit involution of the normal breast in Caucasian and African American women: The Susan G. Komen Tissue Bank.

    Science.gov (United States)

    Oh, Hannah; Pfeiffer, Ruth M; Falk, Roni T; Horne, Hisani N; Xiang, Jackie; Pollak, Michael; Brinton, Louise A; Storniolo, Anna Maria V; Sherman, Mark E; Gierach, Gretchen L; Figueroa, Jonine D

    2018-02-22

    Lesser degrees of terminal duct lobular unit (TDLU) involution, as reflected by higher numbers of TDLUs and acini/TDLU, are associated with elevated breast cancer risk. In rodent models, the insulin-like growth factor (IGF) system regulates involution of the mammary gland. We examined associations of circulating IGF measures with TDLU involution in normal breast tissues among women without precancerous lesions. Among 715 Caucasian and 283 African American (AA) women who donated normal breast tissue samples to the Komen Tissue Bank between 2009 and 2012 (75% premenopausal), serum concentrations of IGF-I and binding protein (IGFBP)-3 were quantified using enzyme-linked immunosorbent assay. Hematoxilyn and eosin-stained tissue sections were assessed for numbers of TDLUs ("TDLU count"). Zero-inflated Poisson regression models with a robust variance estimator were used to estimate relative risks (RRs) for association of IGF measures (tertiles) with TDLU count by race and menopausal status, adjusting for potential confounders. AA (vs. Caucasian) women had higher age-adjusted mean levels of serum IGF-I (137 vs. 131 ng/mL, p = 0.07) and lower levels of IGFBP-3 (4165 vs. 4684 ng/mL, p IGF-I:IGFBP-3 ratios were associated with higher TDLU count in Caucasian (RR T3vs.T1 =1.33, 95% CI = 1.02-1.75, p-trend = 0.04), but not in AA (RR T3vs.T1 =0.65, 95% CI = 0.42-1.00, p-trend = 0.05), women. Our data suggest a role of the IGF system, particularly IGFBP-3, in TDLU involution of the normal breast, a breast cancer risk factor, among Caucasian and AA women. © 2018 UICC.

  19. Dye-sensitized solar cells based on nanostructured zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

    2009-07-01

    Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

  20. Characteristics of dye-sensitized solar cells using natural dye

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Shoji, E-mail: furukawa@cse.kyutech.ac.j [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan); Iino, Hiroshi; Iwamoto, Tomohisa; Kukita, Koudai; Yamauchi, Shoji [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan)

    2009-11-30

    Dye-sensitized solar cells are expected to be used for future clean energy. Recently, most of the researchers in this field use Ruthenium complex as dye in the dye-sensitized solar cells. However, Ruthenium is a rare metal, so the cost of the Ruthenium complex is very high. In this paper, various dye-sensitized solar cells have been fabricated using natural dye, such as the dye of red-cabbage, curcumin, and red-perilla. As a result, it was found that the conversion efficiency of the solar cell fabricated using the mixture of red-cabbage and curcumin was about 0.6% (light source: halogen lamp), which was larger than that of the solar cells using one kind of dye. It was also found that the conversion efficiency was about 1.0% for the solar cell with the oxide semiconductor film fabricated using polyethylene glycol (PEG) whose molecular weight was 2,000,000 and red-cabbage dye. This indicates that the cost performance (defined by [conversion efficiency]/[cost of dye]) of the latter solar cell (dye: red-cabbage) is larger by more than 50 times than that of the solar cell using Ruthenium complex, even if the effect of the difference between the halogen lamp and the standard light source is taken into account.

  1. Caffeine markedly sensitizes human mesothelioma cell lines to pemetrexed

    Science.gov (United States)

    Min, Sang Hee; Goldman, I. David; Zhao, Rongbao

    2013-01-01

    Pemetrexed is a new generation antifolate approved for the treatment of mesothelioma and non-small cell lung cancer. Caffeine is known to augment radiation or chemotherapeutic drug-induced cell killing. The current study addresses the impact of caffeine on the activity of pemetrexed in mesothelioma cell lines. Caffeine enhanced pemetrexed activity in all four mesothelioma cell lines tested (H2052, H2373, H28 and MSTO-211H). Caffeine sensitized H2052 cells in a dose- and schedule-dependent manner, and was associated with a markedly decreased clonogenic survival. Caffeine sensitization occurred only in cells subjected to pulse, but not continuous, exposure to pemetrexed. Similar pemetrexed sensitization was also observed with the clinically better tolerated caffeine analog, theobromine. Pemetrexed sensitization by caffeine was associated with an increase in pemetrexed-induced phosphorylation of ataxia-telangiectasia-mutated (ATM) and Chk1. These data indicate that caffeine and its analog, theobromine, may be a useful approach to enhance pemetrexed-based chemotherapy. PMID:17594092

  2. Recent Advances in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    F. O. Lenzmann

    2007-01-01

    Full Text Available This review describes recent advances in the research on dye-sensitized solar cells. After a brief discussion of the general operation principles and a presentation of record efficiencies, stability data and key technology drivers, current trends will be reviewed. The focus of this review is on materials development (sensitizers, nanostructured oxide films, and electrolyte, but commercialization aspects will also be briefly addressed. The review describes the most relevant characteristics and major trends in a compact way.

  3. A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

    KAUST Repository

    Ball, James M.

    2012-01-01

    The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin-based dyes. We show that by fusing the porphyrin core to an anthracene unit, we can extend the conjugation length and lower the optical gap, shifting the absorption spectrum into the near-infrared (NIR). All three dyes were tested in dye-sensitized solar cells, using both titanium dioxide and tin dioxide as the electron-transport material. Solar cells incorporating the anthracene-fused porphyrin dye exhibit photocurrent collection at wavelengths up to about 1100 nm, which is the longest reported for a porphyrin-based system. Despite extending the photon absorption bandwidth, device efficiency is found to be low, which is a common property of cells based on porphyrin dyes with NIR absorption. We show that in the present case the efficiency is reduced by inefficient electron injection into the oxide, as opposed to dye regeneration, and highlight some important design considerations for panchromatic sensitizers. © 2012 The Royal Society of Chemistry.

  4. Plectin deficiency in liver cancer cells promotes cell migration and sensitivity to sorafenib treatment.

    Science.gov (United States)

    Cheng, Chiung-Chi; Chao, Wei-Ting; Liao, Chen-Chun; Tseng, Yu-Hui; Lai, Yen-Chang Clark; Lai, Yih-Shyong; Hsu, Yung-Hsiang; Liu, Yi-Hsiang

    2018-01-02

    Plectin involved in activation of kinases in cell signaling pathway and plays important role in cell morphology and migration. Plectin knockdown promotes cell migration by activating focal adhesion kinase and Rac1-GTPase activity in liver cells. Sorafenib is a multi-targeting tyrosine kinase inhibitor that improves patient survival on hepatocellular carcinoma. The aim of this study is to investigate the correlation between the expression of plectin and cell migration as well as the sensitivity of hepatoma cell lines exposing to sorafenib. Hepatoma cell lines PLC/PRF/5 and HepG2 were used to examine the level of plectin expression and cell migration in comparison with Chang liver cell line. In addition, sensitivity of the 3 cell lines to sorafenib treatment was also measured. Expression of plectin was lower in PLC/PRF/5 and HepG2 hepatoma cells than that of Chang liver cells whereas HepG2 and PLC/PRF/5 cells exhibit higher rate of cell migration in trans-well migration assay. Immunohistofluorecent staining on E-cadherin revealed the highest rate of collective cell migration in HepG2 cells and the lowest was found in Chang liver cells. Likewise, HepG2 cell line was most sensitive to sorafenib treatment and Chang liver cells exhibited the least sensitivity. The drug sensitivity to sorafenib treatment showed inverse correlation with the expression of plectin. We suggest that plectin deficiency and increased E-cadherin in hepatoma cells were associated with higher rates of cell motility, collective cell migration as well as higher drug sensitivity to sorafenib treatment.

  5. Inhibition of histone deacetylases sensitizes glioblastoma cells to lomustine

    DEFF Research Database (Denmark)

    Staberg, Mikkel; Michaelsen, Signe Regner; Rasmussen, Rikke Darling

    2017-01-01

    the sensitizing effect of the HDACi trichostatin A (TSA) to the alkylating agent lomustine (CCNU), which is used in the clinic for the treatment of GBM. METHODS: Twelve primary GBM cell cultures grown as neurospheres were used in this study, as well as one established GBM-derived cell line (U87 MG). Histone...... are problems that call for a prompt development of novel therapeutic strategies. While only displaying modest efficacies as mono-therapy in pre-clinical settings, histone deacetylase inhibitors (HDACi) have shown promising sensitizing effects to a number of cytotoxic agents. Here, we sought to investigate...

  6. Ionic liquid electrolytes for dye-sensitized solar cells.

    Science.gov (United States)

    Gorlov, Mikhail; Kloo, Lars

    2008-05-28

    The potential of room-temperature molten salts (ionic liquids) as solvents for electrolytes for dye-sensitized solar cells has been investigated during the last decade. The non-volatility, good solvent properties and high electrochemical stability of ionic liquids make them attractive solvents in contrast to volatile organic solvents. Despite this, the relatively high viscosity of ionic liquids leads to mass-transport limitations. Here we review recent developments in the application of different ionic liquids as solvents or components of liquid and quasi-solid electrolytes for dye-sensitized solar cells.

  7. Stem cell mobilization in idiopathic steroid-sensitive nephrotic syndrome.

    Science.gov (United States)

    Lapillonne, Hélène; Leclerc, Annelaure; Ulinski, Tim; Balu, Laurent; Garnier, Arnaud; Dereuddre-Bosquet, Nathalie; Watier, Hervé; Schlageter, Marie-Hélène; Deschênes, Georges

    2008-08-01

    Steroid-sensitive nephrotic syndrome (SSNS) is classically thought to be a T-cell disorder. The aim of this study was to examine whether or not thymus homeostasis was affected in SSNS. Mature and naive T cell recent thymic emigrants were quantified in the peripheral blood of nephrotic patients and controls. Because the generation of new T cells by the thymus ultimately depends on hematopoietic stem cells, CD34+ cells were also included in the study. Nineteen patients with SSNS during relapse, 13 with SSNS during proteinuria remission, and 18 controls were studied. Cell-surface markers (CD3, CD4, CD8, CD19, CD16, CD56, CD45RA, CD62L, CD34, and CD38) were analyzed by flow cytometric analysis. T-cell rearrangement excision circles (TRECs) were quantified in CD2+ cells by real-time polymerase chain reaction. Stroma cell-derived factor-1 (SDF-1) genotype and metalloproteinase-9 (MMP-9) plasma levels were also determined. Mature T cells (CD4+ and CD8+), circulating naive T cells (CD62L+ and CD3+ CD62L+), and recent thymic emigrants (CD45RA+) as well as TRECs, that measure thymus production, had a similar level in the three groups of patients. Conversely, CD34+ hematopoietic stem cells displayed a two-fold increase in SSNS patients during relapse either compared with controls or SSNS patients at remission. In addition, compared with controls, SSNS patients at remission displayed (1) a decrease in CD19+ cells (B cells) and (2) an increase in CD16CD56+ cells [natural killer (NK) cells]. In conclusion, thymus homeostasis is not significantly affected in nephrotic patients. Hematopoietic stem-cell mobilization at proteinuria relapse, as well as changes in B and NK cells during remission, suggest that SSNS might be due to a general disturbance of hematopoietic and immune cell trafficking.

  8. Apoptotic potential and cell sensitivity to fractionated radiotherapy

    International Nuclear Information System (INIS)

    Rupnow, Brent A.; Murtha, Albert D.; Alarcon, Rodolfo M.; Giaccia, Amato J.; Knox, Susan J.

    1997-01-01

    Purpose/Objective: At present, the relationship between sensitivity to radiation-induced apoptosis and overall cellular radiosensitivity remains unclear. In particular, the relationship of apoptotic sensitivity to the survival of cells following fractionated irradiation has not been well studied. The purpose of the present study was to determine if increasing cell sensitivity to radiation-induced apoptosis would result in decreased clonogenic survival following single dose and fractionated irradiation in vitro. Materials and Methods: To address this, we chose a cell line (Rat-1MycER) in which the sensitivity to radiation-induced apoptosis could be altered by switching on or off the activity of a conditional c-Myc allele (c-MycER). The c-MycER construct expresses a full length c-Myc protein fused to a modified hormone binding domain of the estrogen receptor. Only in the presence of the estrogen analog 4-hydroxytamoxifen (4HT), does the conditional c-MycER become active. Apoptosis following irradiation in these cells (with and without c-MycER activation) was analyzed by flow cytometry to determine the percentage of cells undergoing apoptosis following various radiation doses and at different times after irradiation. Additionally, clonogenic survival analysis was performed following single radiation doses from 0 to 10 Gy and following five fractions of 2 or 4 Gy each. Survival of cells with and without c-MycER activation was compared. Furthermore, the effect of overexpressing the anti-apoptotic Bcl-2 gene on apoptosis induction and clonogenic survival of these cells was examined. Results: Rat-1MycER cells were strongly sensitized to radiation-induced apoptosis in a dose and time dependent manner when MycER was activated relative to cells treated without c-MycER activation. This c-Myc-mediated sensitivity to radiation-induced apoptosis was suppressed by overexpression of the anti-apoptotic protein Bcl-2. In addition to increasing apoptosis, activating c-MycER prior to

  9. Photodamage of the cells in culture sensitized with bilirubin

    Science.gov (United States)

    Kozlenkova, O. A.; Plavskaya, L. G.; Mikulich, A. V.; Leusenko, I. A.; Tretyakova, A. I.; Plavskii, V. Yu

    2016-08-01

    It has been shown that exposure to radiation of LED sources of light with an emission band maximum at about 465 and 520 nm having substantially identical damaging effects on animal cells in culture, that are in a logarithmic growth phase and preincubated with pigment. Photobiological effect is caused by photodynamic processes involving singlet oxygen generated by triplet excited sensitizer. Mono-exponential type dependence of cell survival on the energy dose indicates that it is bilirubin that acts as a sensitizer but not its photoproducts. The inclusion of bilirubin in the cells, where it is primarily localized in the mitochondria cells, it is accompanied by multiple amplification photochemical stability compared to pigment molecules bound with albumin

  10. Chemoprotective effect of insulin-like growth factor I against acetaminophen-induced cell death in Chang liver cells via ERK1/2 activation

    International Nuclear Information System (INIS)

    Hwang, Hye-Jung; Kwon, Mi-Jin; Nam, Taek-Jeong

    2007-01-01

    The insulin-like growth factor (IGF) system and type-I IGF receptor (IGF-IR) signaling are involved in protecting against chemotherapeutic drug-induced cell death in human hepatoma cells. Acetaminophen (AAP) hepatotoxicity is the leading cause of liver failure, and the prevention of AAP-induced cell death has been the focus of many studies. We determined whether IGF-I could protect against AAP-induced cell death in Chang liver cells and investigated the protective mechanism. Based on the results of MTS assays, LDH release assays, Hoechst 33342 cell staining, and DNA fragmentation experiments, AAP induced cell death in a dose-dependent manner. According to Western blot analysis, treatment with AAP increased the level of poly(ADP-ribose) polymerase (PARP) fragments in cells compared with that in control cells; however, caspase-3, a critical signaling molecule in apoptosis, was not activated after AAP overdose. Moreover, combined treatment with AAP and IGF-I inhibited PARP cleavage, which was consistent with the ability of IGF-I to restore the level of glutathione (GSH) and cell viability in GSH and MTS assays, respectively. We investigated whether the protective effect of IGF-I against AAP cytotoxicity is related to the extracellular signal-related kinase ERK1/2, which is generally activated by mitogenic and proliferative stimuli such as growth factors. Compared with AAP treatment alone, IGF-I and AAP co-treatment increased ERK1/2 phosphorylation but inhibited PARP cleavage. Thus ERK1/2 activation is instrumental in the protective effect of IGF-I against AAP-induced cell death in Chang liver cells

  11. Heterogeneity reduces sensitivity of cell death for TNF-Stimuli

    Directory of Open Access Journals (Sweden)

    Schliemann Monica

    2011-12-01

    Full Text Available Abstract Background Apoptosis is a form of programmed cell death essential for the maintenance of homeostasis and the removal of potentially damaged cells in multicellular organisms. By binding its cognate membrane receptor, TNF receptor type 1 (TNF-R1, the proinflammatory cytokine Tumor Necrosis Factor (TNF activates pro-apoptotic signaling via caspase activation, but at the same time also stimulates nuclear factor κB (NF-κB-mediated survival pathways. Differential dose-response relationships of these two major TNF signaling pathways have been described experimentally and using mathematical modeling. However, the quantitative analysis of the complex interplay between pro- and anti-apoptotic signaling pathways is an open question as it is challenging for several reasons: the overall signaling network is complex, various time scales are present, and cells respond quantitatively and qualitatively in a heterogeneous manner. Results This study analyzes the complex interplay of the crosstalk of TNF-R1 induced pro- and anti-apoptotic signaling pathways based on an experimentally validated mathematical model. The mathematical model describes the temporal responses on both the single cell level as well as the level of a heterogeneous cell population, as observed in the respective quantitative experiments using TNF-R1 stimuli of different strengths and durations. Global sensitivity of the heterogeneous population was quantified by measuring the average gradient of time of death versus each population parameter. This global sensitivity analysis uncovers the concentrations of Caspase-8 and Caspase-3, and their respective inhibitors BAR and XIAP, as key elements for deciding the cell's fate. A simulated knockout of the NF-κB-mediated anti-apoptotic signaling reveals the importance of this pathway for delaying the time of death, reducing the death rate in the case of pulse stimulation and significantly increasing cell-to-cell variability. Conclusions Cell

  12. Solid State Polymer Electrolytes for Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Over the past decade,Dye-sensitized solar cells (DSSCs) have been intensively investigated as potential alternatives to conventional inorganic photovoltaic devices due to their low production cost and high energy conversion[1-4]. This type of solar cell has achieved an impressive energy conversion efficiency of over 10%,whose electrolyte is a voltaic organic liquid solvent containing iodide/triiodide as redox couple.However,the use of a liquid electrolyte brings difficulties in the practi...

  13. Radiation sensitization studies by silymarin on HCT-15 cells

    International Nuclear Information System (INIS)

    Lal, Mitu; Gupta, Damodar; Arora, R.

    2014-01-01

    Radiotherapy has been widely used for treatment of human cancers. However, cancer cells develop radioresistant phenotypes following multiple exposures to the treatment agent that decrease the efficacy of radiotherapy. Here it was investigated that the radiation sensitization effects of silymarin found in colon cancer. The aim of this study was to investigate mechanisms involved in radiation sensitization growth inhibitory effect of silymarin in combination with radiation, in Human colon carcinoma (HCT-15). The human colon carcinoma was utilized and SRB-assay was performed to study anti-proliferative effect of silymarin in combination with gamma radiation (2 Gy) appropriate radiation dose was optimized and confirmed by clonogenic assay. Microscopic analysis was done by staining with Hoechst-33342, DAPI, Propidium iodide to confirm the presence of apoptosis. Nitric oxide production, changes in lipid peroxidation, Cell cycle analysis were carried out and mitochondrial membrane potential was measured by uptake of cationic dye JC-1 by using flow cytometer. Silymarin in combination with radiation (2 Gy) inhibited 70% ± 5% population growth of HCT-15 cells in time and dose dependent manner. Pre treatment of cells with silymarin for 30 min before radiation was found to be most effective for radiation sensitization. There was 25% increase in levels of nitric oxide as compare to control, whereas 2.5 fold change in lipid peroxidation with respect to control. IR-induced apoptosis in HCT-15 cell line was significantly enhanced by silymarin, as reflected by viability, DNA fragmentation, and mitochondrial dysfunction. Additionally, silymarin in combination with IR is found to be effective in sensitization of HCT-15 cells. In vivo studies on development of tumor and sensitization aspects needs to done in future. (author)

  14. Assessment of the dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R. D. [Center for Basic Sciences, National Renewable Energy Laboratory, MIS 3211, 1617 Cole Boulevard, Golden, CO 80401 (United States)

    2002-09-01

    The field of solar electricity, or photovoltaics (PV), is rich in that there are many materials and concepts for converting sunlight into electricity. The technologies accepted as conventional are those well along in the process of commercialization. The dye-sensitized solar cell, developed in the 1990s, is a nonconventional solar electric technology that has attracted much attention, perhaps a result of its record cell efficiency above 10%. This paper reviews the technology, discusses new research results and approaches presented at a recent symposium of many of the world's important dye solar cell researchers, and presents an assessment of the dye-sensitized solar cell in a comparison with current conventional solar electric technologies. It concludes the dye solar cell has potential for becoming a cost-effective means for producing electricity, capable of competing with available solar electric technologies and, eventually, with today's conventional power technologies. But it is a relatively new technology and faces many hurdles on the path to commercialization. Because of its potential, this assessment recommends further funding for research and development (RandD) of the dye-sensitized solar cell technology on the basis of the promising technical characteristics of the technology, a strong US and worldwide research base, positive industry interest, and today's relatively small funding allocation for its RandD. (Author)

  15. Effect of the association of IGF-I, IGF-II, bFGF, TGF-beta1, GM-CSF, and LIF on the development of bovine embryos produced in vitro.

    Science.gov (United States)

    Neira, J A; Tainturier, D; Peña, M A; Martal, J

    2010-03-15

    This study examined the influence of the following growth factors and cytokines on early embryonic development: insulin-like growth factors I and II (IGF-I, IGF-II), basic fibroblast growth factor (bFGF), transforming growth factor (TGF-beta), granulocyte-macrophage colony-stimulating factor (GM-CSF), and leukemia inhibitory factor (LIF). Synthetic oviduct fluid (SOF) was used as the culture medium. We studied the development of bovine embryos produced in vitro and cultured until Day 9 after fertilization. TGF-beta1, bFGF, GM-CSF, and LIF used on their own significantly improved the yield of hatched blastocysts. IGF-I, bFGF, TGF-beta1, GM-CSF, and LIF significantly accelerated embryonic development, especially the change from the expanded blastocyst to hatched blastocyst stages. Use of a combination of these growth factors and cytokines (GF-CYK) in SOF medium produced higher percentages of blastocysts and hatched blastocysts than did use of SOF alone (45% and 22% vs. 24% and 12%; PGM-CSF, produces similar results to 10% fetal calf serum for the development of in vitro-produced bovine embryos. This entirely synthetic method of embryo culture has undeniable advantages for the biosecurity of embryo transfer. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Modification of cellular thermal sensitivity by cell shape

    International Nuclear Information System (INIS)

    Yasui, L.S.; Kaysen, K.L.

    1987-01-01

    Suspension cultured cells have been generally found to be more resistant to thermal cell kill than monolayer cells. The authors found in CHO cells grown in F10 medium that suspension cultured cells were more resistant to heat at temperatures greater than 43 0 . At 43 0 and 41.5 0 , the clonogenicity was equal. The T/sub 0/ for 43 0 , 44 0 and 46 0 was 15, 1.5 and 1.25 min for monolayer and 15, 10 and 3.75 min for suspension cultured cells, respectively. The difference in heat sensitivities was not due to a trypsin effect or duration of culturing time in suspension. Microscopic examination of the cells showed monolayer cells were flattened while suspension cells were rounded and each had a corresponding altered organization of the cytoskeleton. The amount of cell protein per 10/sup 5/ cells as determined by the standard Lowry assay was approximately equal for both groups at 31 μg protein. When cells were labeled with /sup 3/H-leucine, heated (45 0 , 15 min) and then extracted so only a cytoskeletal fraction remained, they found an increase in protein in heated over unheated cells. Additionally, the polypeptide banding pattern differed in heated (45 0 , 15min) monolayer versus suspension cells with the appearance of a band at about 64 kD in monolayer cells but not in suspension cells. These results indicate that cell shape, as determined by the underlying cytoskeletal organization, modifies the cellular response to thermal exposure

  17. Dye-sensitized solar cells: a successful combination of materials

    Directory of Open Access Journals (Sweden)

    Longo Claudia

    2003-01-01

    Full Text Available Dye-sensitized TiO2 solar cells, DSSC, are a promising alternative for the development of a new generation of photovoltaic devices. DSSC are a successful combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox-couple and a Pt coated counter-electrode. In general, Ru bipyridyl complexes are used as the dye sensitizers. The light-to-energy conversion performance of the cell depends on the relative energy levels of the semiconductor and dye and on the kinetics of the electron-transfer processes at the sensitized semiconductor | electrolyte interface. The rate of these processes depends on the properties of its components. This contribution presents a discussion on the influence of each of the materials which constitute the DSSC of the overall process for energy conversion. An overview of the results obtained for solid-state dye-sensitized TiO2 solar cells assembled with polymer electrolytes is also presented.

  18. Natural dyes as photosensitizers for dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Sancun; Wu, Jihuai; Huang, Yunfang; Lin, Jianming [Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou, Fujian 362021 (China)

    2006-02-15

    The dye-sensitized solar cells (DSC) were assembled by using natural dyes extracted from black rice, capsicum, erythrina variegata flower, rosa xanthina, and kelp as sensitizers. The I{sub SC} from 1.142mA to 0.225mA, the V{sub OC} from 0.551V to 0.412V, the fill factor from 0.52 to 0.63, and P{sub max} from 58{mu}W to 327{mu}W were obtained from the DSC sensitized with natural dye extracts. In the extracts of natural fruit, leaves and flower chosen, the black rice extract performed the best photosensitized effect, which was due to the better interaction between the carbonyl and hydroxyl groups of anthocyanin molecule on black rice extract and the surface of TiO{sub 2} porous film. The blue-shift of absorption wavelength of the black rice extract in ethanol solution on TiO{sub 2} film and the blue-shift phenomenon from absorption spectrum to photoaction spectrum of DSC sensitized with black rice extract are discussed in the paper. Because of the simple preparation technique, widely available and low cheap cost natural dye as an alternative sensitizer for dye-sensitized solar cell is promising. (author)

  19. Fabrication of dye-sensitized solar cells with multilayer photoanodes

    Indian Academy of Sciences (India)

    Volume 39 Issue 6 October 2016 pp 1403-1410 ... Keywords. Dye-sensitized solar cells; hydrothermal method; TiO 2 nanocrystals; multilayer photoanodes; energy conversion efficiency. ... Higher energy conversion efficiencies were also attainable using two transparent sub-layers of hydrothermally grown TiO 2 NCs.

  20. Efficient eco-friendly inverted quantum dot sensitized solar cells

    NARCIS (Netherlands)

    Park, Jinhyung; Sajjad, Muhammad T.; Jouneau, Pierre-Henri; Ruseckas, Arvydas; Faure-Vincent, Jérôme; Samuel, Ifor D. W.; Reiss, Peter; Aldakov, Dmitry

    2016-01-01

    Recent progress in quantum dot (QD) sensitized solar cells has demonstrated the possibility of low-cost and efficient photovoltaics. However, the standard device structure based on n-type materials often suffers from slow hole injection rate, which may lead to unbalanced charge transport. We have

  1. Exploiting Nanocarbons in Dye-Sensitized Solar Cells

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav

    2014-01-01

    Roč. 348, č. 2014 (2014), s. 53-94 ISSN 0340-1022 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : Dye sensitized solar cells * Carbon nanotubes * Graphene Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.464, year: 2014

  2. Interplay between transparency and efficiency in dye sensitized solar cells.

    Science.gov (United States)

    Tagliaferro, Roberto; Colonna, Daniele; Brown, Thomas M; Reale, Andrea; Di Carlo, Aldo

    2013-02-11

    In this paper we analyze the interplay between transparency and efficiency in dye sensitized solar cells by varying fabrication parameters such as the thickness of the nano-crystalline TiO(2) layer, the dye loading and the dye type. Both transparency and efficiency show a saturation trend when plotted versus dye loading. By introducing the transparency-efficiency plot, we show that the relation between transparency and efficiency is linear and is almost independent on the TiO(2) thickness for a certain thickness range. On the contrary, the relation between transparency and efficiency depends strongly on the type of the dye. Moreover, we show that co-sensitization techniques can be effectively used to access regions of the transparency-efficiency space that are forbidden for single dye sensitization. The relation found between transparency and efficiency (T&E) can be the general guide for optimization of Dye Solar Cells in building integration applications.

  3. Effects of growth factors and glucosamine on porcine mandibular condylar cartilage cells and hyaline cartilage cells for tissue engineering applications.

    Science.gov (United States)

    Wang, Limin; Detamore, Michael S

    2009-01-01

    Temporomandibular joint (TMJ) condylar cartilage is a distinct cartilage that has both fibrocartilaginous and hyaline-like character, with a thin proliferative zone that separates the fibrocartilaginous fibrous zone at the surface from the hyaline-like mature and hypertrophic zones below. In this study, we compared the effects of insulin-like growth factor-I (IGF-I), basic fibroblast growth factor (bFGF), transforming growth factor beta1 (TGF-beta1), and glucosamine sulphate on porcine TMJ condylar cartilage and ankle cartilage cells in monolayer culture. In general, TMJ condylar cartilage cells proliferated faster than ankle cartilage cells, while ankle cells produced significantly greater amounts of glycosaminoglycans (GAGs) and collagen than TMJ condylar cartilage cells. IGF-I and bFGF were potent stimulators of TMJ cell proliferation, while no signals statistically outperformed controls for ankle cell proliferation. IGF-I was the most effective signal for GAG production with ankle cells, and the most potent upregulator of collagen synthesis for both cell types. Glucosamine sulphate promoted cell proliferation and biosynthesis at specific concentrations and outperformed growth factors in certain instances. In conclusion, hyaline cartilage cells had lower cell numbers and superior biosynthesis compared to TMJ condylar cartilage cells, and we have found IGF-I at 100 ng/mL and glucosamine sulphate at 100 microg/mL to be the most effective signals for these cells under the prescribed conditions.

  4. Distribution of IGF receptors in the plasma membrane of proximal tubular cells

    International Nuclear Information System (INIS)

    Hammerman, M.R.; Rogers, S.

    1987-01-01

    To characterize the distribution of receptors for insulin-like growth factors I and II (IGF I and II) in the plasma membrane of the renal proximal tubular cell, the authors measured binding of 125 I-labeled IGF I and 125 I-labeled IGF II to proximal tubular basolateral and brush-border membranes and characterized IGF I-stimulated phosphorylation of detergent-solubilized membranes. 125 I-IGF bound primarily to a 135,000 relative molecular weight (M r ) protein and IGF II to a 260,000 M r protein in isolated membranes. Binding of 125 I-IGF I was severalfold greater in basolateral than in brush-border membranes. IGF I-stimulated phosphorylation of the 92,000 M r β-subunit of its receptors could be demonstrated only in basolateral membranes. These findings are consistent with an asymmetrical distribution of receptors for IGF I in the plasma membrane of the renal proximal tubular cell, localization being primary on the basolateral side. In contrast, binding of 125 I-IGF II to isolated basolateral and brush-border membranes was equivalent, suggesting that receptors for this peptide are distributed more symmetrically in the plasma membrane. The findings suggest that the action of IGF I in proximal tubule are mediated via interaction of circulating peptide with specific receptors in the basolateral membrane. However, the findings established the potential for actions of IGF II to be exerted in proximal tubule via interaction with both basolateral and/or brush-border membrane receptors

  5. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  6. Brief Overview of Dye-Sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hagfeldt, Anders (Dept. of Chemistry, Aangstroem, Uppsala Univ., Uppsala (Sweden); Center for Molecular Devices, KTH-Royal Inst. of Technology, Stockholm (Sweden)), E-mail: anders.hagfeldt@kemi.uu.se

    2012-03-15

    Dye-sensitized solar cells (DSC) are based on molecular and nanometer-scale components. Record cell efficiencies of 12%, promising stability data and means of energy-efficient production methods have been accomplished. As selling points for the DSC technology the prospect of low-cost investments and fabrication are key features. DSCs offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. The basic principles of the operation of DSC, the state-of-the-art as well as the potentials for future development are described

  7. Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging

    International Nuclear Information System (INIS)

    Flusberg, Deborah A; Sorger, Peter K

    2013-01-01

    TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization. (paper)

  8. 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

    Science.gov (United States)

    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.

  9. Sensitization of ultraviolet radiation damage in bacteria and mammalian cells

    International Nuclear Information System (INIS)

    Fisher, G.J.; Watts, M.E.; Patel, K.B.; Adams, G.E.

    1978-01-01

    Bacteria (Serratia marcescens) and mammalian cells (Chinese hamsters V79-379A) were irradiated in monolayers with ultraviolet light at 254 nm or 365 nm in the presence or absence of radiosensitizing drugs. At 254 nm, killing is very efficient (Dsub(37) approximately equal 1 J m -2 exposure, or approximately equal 6 x 10 4 photons absorbed by DNA per bacterium), and sensitizers have no effect. At 365 nm, cells are not killed in buffer, but are inactivated in the presence of nifurpipone or misonidazole. Lethal exposures (approximately equal 5 x 10 3 J m -2 at 10 nM misonidazole) correspond to about 10 7 photons absorbed by sensitizer molecules per bacterium. Toxicity of stable photoproducts of the drugs is not involved, nor is oxygen required. Hence the transient species formed by photo-excitation of radiosensitizer molecules are capable of killing cells in the absence of other types of radiation damage. (author)

  10. Andrographolide sensitizes prostate cancer cells to TRAIL-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Ruo-Jing Wei

    2018-01-01

    Full Text Available Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL is a promising agent for anticancer therapy. The identification of small molecules that can establish the sensitivity of prostate cancer (PCa cells to TRAIL-induced apoptosis is crucial for the targeted treatment of PCa. PC3, DU145, JAC-1, TsuPr1, and LNCaP cells were treated with Andrographolide (Andro and TRAIL, and the apoptosis was measured using the Annexin V/PI double staining method. Real time-polymerase chain reaction (PCR and Western blot analysis were performed to measure the expression levels of target molecules. RNA interference technique was used to down-regulate the expression of the target protein. We established a nude mouse xenograft model of PCa, which was used to measure the caspase-3 activity in the tumor cells using flow cytometry. In this research study, our results demonstrated that Andro preferentially increased the sensitivity of PCa cells to TRAIL-induced apoptosis at subtoxic concentrations, and the regulation mechanism was related to the up-regulation of DR4. In addition, it also increased the p53 expression and led to the generation of reactive oxygen species (ROS in the cells. Further research revealed that the DR4 inhibition, p53 expression, and ROS generation can significantly reduce the apoptosis induced by the combination of TRAIL and Andro in PCa cells. In conclusion, Andro increases the sensitivity of PCa cells to TRAIL-induced apoptosis through the generation of ROS and up-regulation of p53 and then promotes PCa cell apoptosis associated with the activation of DR4.

  11. Dithiafulvene-based organic sensitizers using pyridine as the acceptor for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jun; Cao, Yaxiong; Liang, Xiaozhong; Zheng, Jingxia; Zhang, Fang [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Wei, Shuxian; Lu, Xiaoqing [College of Science, China University of Petroleum, Qingdao, Shandong 266555 (China); Guo, Kunpeng, E-mail: guokunpeng@tyut.edu.cn [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Shihe, E-mail: chsyang@ust.hk [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2017-05-01

    Three dithiafulvene-based metal-free organic sensitizers all using pyridine as the acceptor but with different π-bridges of phenyl (DTF-Py1), thienyl (DTF-Py2) and phenyl-thienyl (DTF-Py3) have been designed, synthesized and used as photosensitizers for dye-sensitized solar cells (DSCs). Introducing thienyl unit into the π-bridge, as well as extension of the π-bridge can dramatically improve their light harvesting ability and suppress the electron recombination, thus uplifting the performance of DSCs. The overall power conversion efficiency of DSC based on DTF-Py3 shows the highest efficiency of 2.61% with a short-circuit photocurrent density of 7.99 mA cm{sup -2}, an open-circuit photovoltage of 630 mV, and a fill factor of 0.52, under standard global AM 1.5 solar light condition. More importantly, the long-term stability of the DTF-Py3 based DSCs under 500 h light-soaking has been demonstrated. - Highlights: • Dithiafulvene sensitizers using pyridine ring as the acceptor were synthesized for the first time. • The power conversion efficiency of 2.61% was obtained for DTF-Py3 sensitized cell. • DTF-Py3 loaded TiO{sub 2} film shows improved light harvesting ability and suppressed electron recombination.

  12. Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

    KAUST Repository

    Jiao, Chongjun

    2011-07-15

    Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

  13. Cell motility in models of wounded human skin is improved by Gap27 despite raised glucose, insulin and IGFBP-5

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Catherine S.; Berends, Rebecca F. [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom); Flint, David J. [Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE (United Kingdom); Martin, Patricia E.M., E-mail: Patricia.Martin@gcu.ac.uk [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom)

    2013-02-15

    Reducing Cx43 expression stimulates skin wound healing. This is mimicked in models when Cx43 function is blocked by the connexin mimetic peptide Gap27. IGF-I also stimulates wound healing with IGFBP-5 attenuating its actions. Further, the IGF-I to IGFBP-5 ratio is altered in diabetic skin, where wound closure is impaired. We investigated whether Gap27 remains effective in augmenting scrape-wound closure in human skin wound models simulating diabetes-induced changes, using culture conditions with raised glucose, insulin and IGFBP-5. Gap27 increased scrape-wound closure in normal glucose and insulin (NGI) and to a lesser extent in high glucose and insulin (HGI). IGF-I enhanced scrape-wound closure in keratinocytes whereas IGFBP-5 inhibited this response. Gap27 overcame the inhibitory effects of IGFBP-5 on IGF-I activity. Connexin-mediated communication (CMC) was reduced in HGI, despite raised Cx43, and Gap27 significantly decreased CMC in NGI and HGI. IGF-I and IGFBP-5 did not affect CMC. IGF-I increased keratinocyte proliferation in NGI, and Gap27 increased proliferation in NGI to a greater extent than in HGI. We conclude that IGF-I and Gap27 stimulate scrape-wound closure by independent mechanisms with Gap27 inhibiting Cx43 function. Gap27 can enhance wound closure in diabetic conditions, irrespective of the IGF-I:IGFBP-5 balance. - Highlights: ► Human organotypic and keratinocyte ‘diabetic’ skin models were used to demonstrate the ability of Gap27 to improve scrape-wound closure. ► Gap27 enhanced scrape-wound closure by reducing Cx43-mediated communication, whereas IGFBP-5 retarded cell migration. ► IGF-I and IGFBP-5 did not affect connexin-mediated pathways. ► Gap27 can override altered glucose, insulin, IGF-I, and IGFBP-5 in ‘diabetic’ skin models and thus has therapeutic potential.

  14. Sensitization of in vitro mammalian cells by nitrous oxide

    International Nuclear Information System (INIS)

    Ewing, D.

    1984-01-01

    Powers and his colleagues showed almost ten years ago that sensitization by nitrous oxide required two radiolytic products: OH radicals and hydrogen peroxide. That observation with bacterial spores has been confirmed and extended with spores and several strains of bacteria. OH must be present to form hydrogen peroxide, but, in addition, OH must also be present with the hydrogen peroxide for damage to occur. (Reagent hydrogen peroxide, except at very high concentrations, will not sensitize unless OH radicals are present.) The authors have now tested nitrous oxide with two Chinese hamster cell lines, V79 and CHO. The responses in nitrogen and nitrous oxide are the same for each. The authors have tentatively concluded that insufficient hydrogen peroxide is formed in the cells' suspending fluid for damage from nitrous oxide to occur. Several results support this conclusion: reagent hydrogen peroxide is a potent sensitizer of either cell line tested in nitrogen or nitrous oxide and an assay for radiolytic hydrogen peroxide confirms that only minimal levels are formed at the doses used in these survival curves. The authors also present results of other tests to further complement work with procaryotic cells

  15. SITS-sensitive Cl- conductance pathway in chick intestinal cells

    International Nuclear Information System (INIS)

    Montrose, M.; Randles, J.; Kimmich, G.A.

    1987-01-01

    The unidirectional influx of 36 Cl - into isolated chick epithelial cells is 30% inhibited by 300 μM SITS. Characteristics of the SITS-sensitive flux pathway were examined in terms of sensitivity to changes in membrane potential and intracellular pH. Potential dependence was evaluated using unidirectional influx of [ 14 C]tetraphenylphosphonium ([ 14 C]-TPP + ) as a qualitative sensor of diffusion potentials created by experimentally imposed gradients of CL - . Steady-state distribution of [ 14 C]methylamine ([ 14 C]MA) was used to examine for Cl - -dependent changes in intracellular pH. Imposed Na + gradients, but not Cl - gradients, induce changes in [ 14 C]MA distribution. SITS does not alter the [ 14 C]MA distribution observed in cells with imposed gradients of Na + and Cl - . Both results suggest that inhibition of Cl - influx. However, if relative permeabilities for ion pairs via conductance pathways are compared, it can be shown that SITS causes a marked reduction of P Cl relative to either P Na or P K . SITS also inhibits electrically induced influx of [ 14 C]TPP + or [ 14 C]α-methylglucoside driven by imposed Cl - influx can be blocked by SITS. These observations are all consistent with a SITS-sensitive Cl - conductance pathway associated with the plasma membrane of chick intestinal cells. No Cl - -OH - exchange capability can be detected for chick intestinal cells

  16. Identification of a novel EGF-sensitive cell cycle checkpoint

    International Nuclear Information System (INIS)

    Walker, Francesca; Zhang Huihua; Burgess, Antony W.

    2007-01-01

    The site of action of growth factors on mammalian cell cycle has been assigned to the boundary between the G1 and S phases. We show here that Epidermal Growth Factor (EGF) is also required for mitosis. BaF/3 cells expressing the EGFR (BaF/wtEGFR) synthesize DNA in response to EGF, but arrest in S-phase. We have generated a cell line (BaF/ERX) with defective downregulation of the EGFR and sustained activation of EGFR signalling pathways: these cells undergo mitosis in an EGF-dependent manner. The transit of BaF/ERX cells through G2/M strictly requires activation of EGFR and is abolished by AG1478. This phenotype is mimicked by co-expression of ErbB2 in BaF/wtEGFR cells, and abolished by inhibition of the EGFR kinase, suggesting that sustained signalling of the EGFR, through impaired downregulation of the EGFR or heterodimerization, is required for completion of the cycle. We have confirmed the role of EGFR signalling in the G2/M phase of the cell cycle using a human tumor cell line which overexpresses the EGFR and is dependent on EGFR signalling for growth. These findings unmask an EGF-sensitive checkpoint, helping to understand the link between sustained EGFR signalling, proliferation and the acquisition of a radioresistant phenotype in cancer cells

  17. Parametric Sensitivity Tests- European PEM Fuel Cell Stack Test Procedures

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2014-01-01

    performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature......As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests......, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions....

  18. Sulphonated hypocrellin B sensitized photo damage to ascetic hepatoma cells

    International Nuclear Information System (INIS)

    Yue Jiachang; Wang Tiandun; Pang Suzhen; An Jingyi; Jiang Lijing

    1994-01-01

    The cellular uptake of sulphonated hypocrellin (S-HB), as well as photo damage on cellular viability, lipid peroxidation and intrinsic fluorescence quenching of membrane protein was studied. It was found that S-HB suitable dissolved in aqueous solution, its cellular uptake is slower than HB. The photo damage on cellular viability both photo sensitizers was close to each other, however the photo sensitizers were different in physical and chemical properties. The HB photo damage target of cells was membrane, but the sulphonated HB photo damage target of cells may be part of organelles, besides the membrane. the experiments showed the sulphonated HB would be suggested as a potential advantage for photodynamic therapy of tumor in clinical application

  19. 9-β-arabinofuranosyladenine preferentially sensitizes radioresistant squamous cell carcinoma cell lines to x-rays

    International Nuclear Information System (INIS)

    Heaton, D.

    1992-06-01

    The effect of 9-β-arabinofuranosyladenine (ara-A) on sensitivity to the deleterious effects of x-rays was studied in six squamous cell carcinoma cell lines. Three lines were relatively radioresistant, having D 0 values of 2.31 to 2.89 Gy, and the other three lines were relatively radiosensitive, having D 0 values of between 1.07 and 1.45 Gy. Ara-A (50 or 500 μM) was added to cultures 30 min prior to irradiation and removed 30 min after irradiation, and sensitivity was measured in terms of cell survival. The radiosensitizing effect of ara-A was very dependent on the inherent radiosensitivity of the tumor cell line. Fifty micromolar concentrations of ara-A sensitized only the two most radioresistant lines, SCC-12B.2 and JSQ-3. Five hundred micromolar concentrations of ara-A sensitized the more sensitive cell lines, SQ-20B and SQ-9G, but failed to have any effect on the radiation response of the two most sensitive cell lines, SQ-38 and SCC-61. Concentrations of ara-A as low as 10 μM were equally efficient in inhibiting DNA synthesis in all six cell lines. These results suggest that the target for the radiosensitizing effect of ara-A is probably related to the factor controlling the inherent radiosensitivity of human tumor cells. Therefore, ara-A might be useful in overcoming radiation resistance in vivo

  20. 9-{beta}-arabinofuranosyladenine preferentially sensitizes radioresistant squamous cell carcinoma cell lines to x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, D. [Rush Univ. Medical Center, Chicago, IL (United States). Therapeutic Radiology; Mustafi, R. [Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Schwartz, J.L. [Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology]|[Argonne National Lab., IL (United States)

    1992-06-01

    The effect of 9-{beta}-arabinofuranosyladenine (ara-A) on sensitivity to the deleterious effects of x-rays was studied in six squamous cell carcinoma cell lines. Three lines were relatively radioresistant, having D{sub 0} values of 2.31 to 2.89 Gy, and the other three lines were relatively radiosensitive, having D{sub 0} values of between 1.07 and 1.45 Gy. Ara-A (50 or 500 {mu}M) was added to cultures 30 min prior to irradiation and removed 30 min after irradiation, and sensitivity was measured in terms of cell survival. The radiosensitizing effect of ara-A was very dependent on the inherent radiosensitivity of the tumor cell line. Fifty micromolar concentrations of ara-A sensitized only the two most radioresistant lines, SCC-12B.2 and JSQ-3. Five hundred micromolar concentrations of ara-A sensitized the more sensitive cell lines, SQ-20B and SQ-9G, but failed to have any effect on the radiation response of the two most sensitive cell lines, SQ-38 and SCC-61. Concentrations of ara-A as low as 10 {mu}M were equally efficient in inhibiting DNA synthesis in all six cell lines. These results suggest that the target for the radiosensitizing effect of ara-A is probably related to the factor controlling the inherent radiosensitivity of human tumor cells. Therefore, ara-A might be useful in overcoming radiation resistance in vivo.

  1. Novelionic Polymer Electrolytes for Dye Sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Shibi Fang; Yuan Lin

    2005-01-01

    @@ 1Introduction In recent years, dye-sensitized solar cells(DSC) based on nanocrystalline porous TiO2 films have attracted much attention because of their relatively higher efficiency and low cost compared with conventional inorganic photovoltaic devices[1]. This type of solar cell has achieved an impressive photo-to-energy conversion efficiency of over 10% where the electrolyte is volatile organic liquid solvents containing I-/I-3- as redox couple. Because of high volatilities, solvent losses occur during long-term operations, resulting in lowered DSC performances.And leakage of liquid electrolyte also limits the durability of DSC.

  2. Fabrication of Two Columns Dye-Sensitized Solar-Cell

    International Nuclear Information System (INIS)

    Phyu Sin Khaing Oo; Su Su Hlaing; Khin Lay Thwe; Nwe Ni Khin

    2011-12-01

    A two columns dye-sensitized solar cell has been fabricated using dye extract form teak leaves. This solar cell was assembled with two 20-30 ohms conductive glasses (one for TiO2 coated electrode and another for carbon coated electrode), TiO2 nano-powder P25, iodide electrolyte solution and soft graphite pencil for carbon coating. It was found that the open circuit voltage Voc was 0.688V and the short circuit Isc was 0.724mA

  3. The sensitivity of human mesenchymal stem cells to ionizing radiation

    International Nuclear Information System (INIS)

    Chen, M.-F.; Lin, C.-T.; Chen, W.-C.; Yang, C.-T.; Chen, C.-C.; Liao, S.-K.; Liu, J.M.; Lu, C.-H.; Lee, K.-D.

    2006-01-01

    Purpose: Recent studies have shown that mesenchymal stem cells (MSCs) obtained from bone marrow transplantation patients originate from the host. This clinical observation suggests that MSCs in their niches could be resistant to irradiation. However, the biologic responses of bone marrow MSCs to irradiation have rarely been described in the literature. Methods and Materials: In this study, human bone marrow-derived, clonally expanded MSCs were used to investigate their sensitivity to irradiation in vitro, and the cellular mechanisms that may facilitate resistance to irradiation. The human lung cancer cell line A549 and the breast cancer cell line HCC1937 were used as controls for radiosensitivity; the former line has been shown to be radioresistant and the latter radiosensitive. We then examined their in vitro biologic changes and sensitivities to radiation therapy. Results: Our results suggest that MSCs are characterized as resistant to irradiation. Several cellular mechanisms were demonstrated that may facilitate resistance to irradiation: ATM protein phosphorylation, activation of cell-cycle checkpoints, double-strand break repair by homologous recombination and nonhomologous end joining (NHEJ), and the antioxidant capacity for scavenging reactive oxygen species. Conclusions: As demonstrated, MSCs possess a better antioxidant reactive oxygen species-scavenging capacity and active double-strand break repair to facilitate their radioresistance. These findings provide a better understanding of radiation-induced biologic responses in MSCs and may lead to the development of better strategies for stem cell treatment and cancer therapy

  4. Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells.

    Science.gov (United States)

    Cherrington, Ruth; Wood, Benjamin Michael; Salaoru, Iulia; Goodship, Vannessa

    2016-05-04

    Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 µm thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm(2) and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 °C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 ˚C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells.

  5. DNA repair and radiation sensitivity in mammalian cells

    International Nuclear Information System (INIS)

    Chen, D.J.C.; Stackhouse, M.; Chen, D.S.

    1993-01-01

    Ionizing radiation induces various types of damage in mammalian cells including DNA single-strand breaks, DNA double-strand breaks (DSB), DNA-protein cross links, and altered DNA bases. Although human cells can repair many of these lesions there is little detailed knowledge of the nature of the genes and the encoded enzymes that control these repair processes. We report here on the cellular and genetic analyses of DNA double-strand break repair deficient mammalian cells. It has been well established that the DNA double-strand break is one of the major lesions induced by ionizing radiation. Utilizing rodent repair-deficient mutant, we have shown that the genes responsible for DNA double-strand break repair are also responsible for the cellular expression of radiation sensitivity. The molecular genetic analysis of DSB repair in rodent/human hybrid cells indicate that at least 6 different genes in mammalian cells are responsible for the repair of radiation-induced DNA double-strand breaks. Mapping and the prospect of cloning of human radiation repair genes are reviewed. Understanding the molecular and genetic basis of radiation sensitivity and DNA repair in man will provide a rational foundation to predict the individual risk associated with radiation exposure and to prevent radiation-induced genetic damage in the human population

  6. Gimeracil sensitizes cells to radiation via inhibition of homologous recombination

    International Nuclear Information System (INIS)

    Takagi, Masaru; Sakata, Koh-ichi; Someya, Masanori; Tauchi, Hiroshi; Iijima, Kenta; Matsumoto, Yoshihisa; Torigoe, Toshihiko; Takahashi, Akari; Hareyama, Masato; Fukushima, Masakazu

    2010-01-01

    Background and purpose: 5-Chloro-2,4-dihydroxypyridine (Gimeracil) is a component of an oral fluoropyrimidine derivative S-1. Gimeracil is originally added to S-1 to yield prolonged 5-FU concentrations in tumor tissues by inhibiting dihydropyrimidine dehydrogenase, which degrades 5-FU. We found that Gimeracil by itself had the radiosensitizing effect. Methods and materials: We used various cell lines deficient in non-homologous end-joining (NHEJ) or homologous recombination (HR) as well as DLD-1 and HeLa in clonogenic assay. γ-H2AX focus formation and SCneo assay was performed to examine the effects of Gimeracil on DNA double strand break (DSB) repair mechanisms. Results: Results of γ-H2AX focus assay indicated that Gimeracil inhibited DNA DSB repair. It did not sensitize cells deficient in HR but sensitized those deficient in NHEJ. In SCneo assay, Gimeracil reduced the frequency of neo-positive clones. Additionally, it sensitized the cells in S-phase more than in G0/G1. Conclusions: Gimeracil inhibits HR. Because HR plays key roles in the repair of DSBH caused by radiotherapy, Gimeracil may enhance the efficacy of radiotherapy through the suppression of HR-mediated DNA repair pathways.

  7. Testing of new hypoxic cell sensitizers in vivo

    International Nuclear Information System (INIS)

    Stone, H.B.; Sinesi, M.S.

    1982-01-01

    We tested five agents as potential sensitizers of hypoxic cells in vivo in mammary tumors in C3H mice in comparison with misonidazole. The LD/sub 50/2/ for desmethylmisonidazole was 2.7 mg/g body wt, compared to 1.3 for misonidazole. It was as effective in reducing the TCD 50 of MDAH-MCa-4 as were equitoxic doses of misonidazole. the LD/sub 50/2/ of SR-2508 was 3.3 mg/g and was as effective a sensitizer as misonidazole. Ro 07-0741 was more toxic, with an LD/sub 50/2/ of 0.6 mg/g, but was as effective as misonidazole at equitoxic doses. NP-1 was also more toxic than misonidazole (LA/sub 50/2/ = 04 mg/g) but was a less effective sensitizer. Rotenone, which causes sensitization by inhibiting cellular respiration, thus increasing the diffusion distance of oxygen, was extremely toxic (LD/sub 50/2/ - 0.003 mg/g), and systemic respiratory inhibition and the radioprotective effects of the dimethyl sulfoxide used to dissolve it rendered it totally ineffective as a sensitizer in vivo

  8. Targeting Rad50 sensitizes human nasopharyngeal carcinoma cells to radiotherapy

    International Nuclear Information System (INIS)

    Chang, Lihong; Huang, Jiancong; Wang, Kai; Li, Jingjia; Yan, Ruicheng; Zhu, Ling; Ye, Jin; Wu, Xifu; Zhuang, Shimin; Li, Daqing; Zhang, Gehua

    2016-01-01

    The Mre11-Rad50-Nbs1 (MRN) complex is well known for its crucial role in initiating DNA double strand breaks (DSBs) repair pathways to resistant irradiation (IR) injury and thus facilitating radioresistance which severely reduces radiocurability of nasopharyngeal cancer (NPC). Targeting native cellular MRN function would sensitize NPC cells to IR. A recombinant adenovirus containing a mutant Rad50 gene (Ad-RAD50) expressing Rad50 zinc hook domain but lacking the ATPase domain and the Mre11 interaction domain was constructed to disrupt native cellular MRN functions. The effects of Ad-RAD50 on the MRN functions were assessed in NPC cells lines using western blot, co-immunoprecipitation and confocal microscopy analyses. The increased radiosensitivity of transient Ad-RAD50 to IR was examined in NPC cells, including MTT assay, colony formation. The molecular mechanisms of radiosensitization were confirmed by neutral comet assay and western bolts. Nude mice subcutaneous injection, tumor growth curve and TUNEL assay were used to evaluate tumor regression and apoptosis in vivo. Rad50 is remarkably upregulated in NPC cells after IR, implying the critical role of Rad50 in MRN functions. The transient expression of this mutant Rad50 decreased the levels of native cellular Rad50, Mre11 and Nbs1, weakened the interactions among these proteins, abrogated the G2/M arrest induced by DSBs and reduced the DNA repair ability in NPC cells. A combination of IR and mutant RAD50 therapy produced significant tumor cytotoxicity in vitro, with a corresponding increase in DNA damage, prevented proliferation and cell viability. Furthermore, Ad-RAD50 sensitized NPC cells to IR by causing dramatic tumor regression and inducing apoptosis in vivo. Our findings define a novel therapeutic approach to NPC radiosensitization via targeted native cellular Rad50 disruption. The online version of this article (doi:10.1186/s12885-016-2190-8) contains supplementary material, which is available to

  9. Biophotovoltaics: Natural pigments in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Hug, Hubert; Bader, Michael; Mair, Peter; Glatzel, Thilo

    2014-01-01

    Highlights: • Natural pigments are photosensitizers in dye-sensitized solar cells (DSSCs). • Efficiency is still lower compared to synthetic pigments. • The use of natural pigments such as carotenoids and polyphenols is cheap. • General advantages of DSSCs are flexibility, color and transparency. • Usage under diffuse light and therefore, indoor applications are possible. - Abstract: Dye-sensitized solar cells (DSSCs) which are also called Graetzel cells are a novel type of solar cells. Their advantages are mainly low cost production, low energy payback time, flexibility, performance also at diffuse light and multicolor options. DSSCs become more and more interesting since a huge variety of dyes including also natural dyes can be used as light harvesting elements which provide the charge carriers. A wide band gap semiconductor like TiO 2 is used for charge separation and transport. Such a DSSC contains similarities to the photosynthetic apparatus. Therefore, we summarize current available knowledge on natural dyes that have been used in DSSCs which should provide reasonable light harvesting efficiency, sustainability, low cost and easy waste management. Promising natural compounds are carotenoids, polyphenols and chlorophylls

  10. Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

    Science.gov (United States)

    Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

    2018-03-01

    Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

  11. Sensitivity of mitochondria of the mouse liver cells to radiation

    International Nuclear Information System (INIS)

    Shima, Akihiro

    1974-01-01

    In order to study the sensitivity of mitochondria (Mt) of the liver cells to radiation, 0.4 mg of riboflavine (RF) was intraperitoneally injected into mice which had been fed RF deficient food for 13 weeks. Three hours later 400 R of X-ray (190 KVP, 25 mA, 0.5 mmCu, 0.5 mmAl filter, FSD 61.5 cm, and HVL 0.80 mmCu) were irradiated to the whole body, and giant Mt of the liver cells were observed. When the liver cells were observed 24 hours after injection, neither giant Mt nor mitotic findings of Mt were found. All Mt observed were small (1.2 μ), although mice received 400 R of X-ray. (Serizawa, K.)

  12. Dye sensitized solar cells. How do they work?

    International Nuclear Information System (INIS)

    Laurie M, Peter

    2008-01-01

    Dye sensitized solar cells (DSC), also known as Gratzel cells, harvest sunlight using a dye adsorbed onto the high surface area of a porous nanocrystalline titanium dioxide film. Photoexcitation of the dye results in the injection of electrons into the conduction band of the oxide. The dye is regenerated in its original state by donation of electrons from iodide ions presenting an electrolyte that permeates the porous oxide film. The regeneration cycle is completed at a platinum coated cathode at which tri-iodide ions are reduced to iodide ions. DSC has achieved solar conversion efficiencies of over 10% in the laboratory, with best module efficiencies of around 8%. This lecture will describe the fabrication of the basic DSC and discuss the basic Physics and Chemistry of the cell. (Full text)

  13. Review on Metallic and Plastic Flexible Dye Sensitized Solar Cell

    Science.gov (United States)

    Yugis, A. R.; Mansa, R. F.; Sipaut, C. S.

    2015-04-01

    Dye sensitized solar cells (DSSCs) are a promising alternative for the development of a new generation of photovoltaic devices. DSSCs have promoted intense research due to their low cost and eco-friendly advantage over conventional silicon-based crystalline solar cells. In recent years, lightweight flexible types of DSSCs have attracted much intention because of drastic reduction in production cost and more extensive application. The substrate that used as electrode of the DSSCs has a dominant impact on the methods and materials that can be applied to the cell and consequently on the resulting performance of DSSCs. Furthermore, the substrates influence significantly the stability of the device. Although the power conversion efficiency still low compared to traditional glass based DSSCs, flexible DSSCs still have potential to be the most efficient and easily implemented technology.

  14. Review on Metallic and Plastic Flexible Dye Sensitized Solar Cell

    International Nuclear Information System (INIS)

    Yugis, A R; Mansa, R F; Sipaut, C S

    2015-01-01

    Dye sensitized solar cells (DSSCs) are a promising alternative for the development of a new generation of photovoltaic devices. DSSCs have promoted intense research due to their low cost and eco-friendly advantage over conventional silicon-based crystalline solar cells. In recent years, lightweight flexible types of DSSCs have attracted much intention because of drastic reduction in production cost and more extensive application. The substrate that used as electrode of the DSSCs has a dominant impact on the methods and materials that can be applied to the cell and consequently on the resulting performance of DSSCs. Furthermore, the substrates influence significantly the stability of the device. Although the power conversion efficiency still low compared to traditional glass based DSSCs, flexible DSSCs still have potential to be the most efficient and easily implemented technology. (paper)

  15. Sensitivity of mitochondria of the mouse liver cells to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shima, A [Tokyo Univ. (Japan). Faculty of Science

    1974-06-01

    In order to study the sensitivity of mitochondria (Mt) of the liver cells to radiation, 0.4 mg of riboflavine (RF) was intraperitoneally injected into mice which had been fed RF deficient food for 13 weeks. Three hours later 400 R of X-ray (190 KVP, 25 mA, 0.5 mmCu, 0.5 mmAl filter, FSD 61.5 cm, and HVL 0.80 mmCu) were irradiated to the whole body, and giant Mt of the liver cells were observed. When the liver cells were observed 24 hours after injection, neither giant Mt nor mitotic findings of Mt were found. All Mt observed were small (1.2 ..mu..), although mice received 400 R of X-ray.

  16. UMTRA project disposal cell cover biointrusion sensitivity assessment, Revision 1

    International Nuclear Information System (INIS)

    1995-10-01

    This study provides an analysis of potential changes that may take place in a Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell cover system as a result of plant biointrusion. Potential changes are evaluated by performing a sensitivity analysis of the relative impact of root penetrations on radon flux out of the cell cover and/or water infiltration into the cell cover. Data used in this analysis consist of existing information on vegetation growth on selected cell cover systems and information available from published studies and/or other available project research. Consistent with the scope of this paper, no new site-specific data were collected from UMTRA Project sites. Further, this paper does not focus on the issue of plant transport of radon gas or other contaminants out of the disposal cell cover though it is acknowledged that such transport has the potential to be a significant pathway for contaminants to reach the environment during portions of the design life of a disposal cell where plant growth occurs. Rather, this study was performed to evaluate the effects of physical penetration and soil drying caused by plant roots that have and are expected to continue to grow in UMTRA Project disposal cell covers. An understanding of the biological and related physical processes that take place within the cover systems of the UMTRA Project disposal cells helps the U.S. Department of Energy (DOE) determine if the presence of a plant community on these cells is detrimental, beneficial, or of mixed value in terms of the cover system's designed function. Results of this investigation provide information relevant to the formulation of a vegetation control policy

  17. Isolation of cell cycle-dependent gamma ray-sensitive Chinese hamster ovary cell

    International Nuclear Information System (INIS)

    Stamato, T.D.; Weinstein, R.; Giaccia, A.; Mackenzie, L.

    1983-01-01

    A technique for the isolation of gamma ray-sensitive Chinese hamster ovary (CHO) cell mutants is described, which uses nylon cloth replica plating and photography with dark-field illumination to directly monitor colonies for growth after gamma irradiation. Two gamma ray-sensitive mutants were isolated using this method. One of these cells (XR-1) had a two-slope survival curve: an initial steep slope and then a flattening of the curve at about 10% survival. Subsequently, it was found that this cell is sensitive to gamma irradiation in G1, early S, and late G2 phases of the cell cycle, whereas in the resistant phase (late S phase) its survival approaches that of the parental cells. The D37 in the sensitive G1 period is approximately 30 rads, compared with 300 rads of the parental cell. This mutant cell is also sensitive to killing by the DNA breaking agent, bleomycin, but is relatively insensitive to UV light and ethyl methane sulfonate, suggesting that the defect is specific for agents that produce DNA strand breakage

  18. Photostability of the solar cell dye sensitizer N719

    DEFF Research Database (Denmark)

    Nour-Mohammadi, Farahnaz

    intensities. This light intensity dependency of the quantum yield was attributed to the back electron transfer reaction rate between the titanium dioxide conduction band electrons and the oxidized dye cation. Photoinduced absorption spectroscopy (PIA) was used to measure the back electron transfer reaction...... rate, kback at the same light intensities as used in the model experiments. The PIA measurements showed that kback increased with increasing light intensities. By applying the equation kdeg = Φdeg × kback to the experimentally obtained total quantum yields and back electron transfer rates......The photostability of the sensitizer dye [Ru(dcbpyH)2(NCS)2] (Bu4N)2 (referred to as N719) was investigated in a simple model system instead of a complete nanocrystaline dye sensitized titanium dioxide solar cells (nc-DSSC). The applied model system consisted of N719 dyed titanium dioxide...

  19. Green grasses as light harvesters in dye sensitized solar cells

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-01

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  20. Green grasses as light harvesters in dye sensitized solar cells.

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-25

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Sensitization of Xanthophylls-Chlorophyllin Mixtures on Titania Solar Cells

    Directory of Open Access Journals (Sweden)

    Indriana Kartini

    2015-03-01

    Full Text Available Co-sensitization of natural dyes on TiO2 for dye-sensitized solar cell (DSSC was proposed between chlorophyllin (C and xanthophylls (X at various volume ratios of C/X. Chlorophyllin is chlorophyll derivative providing -COOH groups essential for binding to TiO2. The chlorophyll was extracted from dried spinach (amaranthus viridis leaves in a mixture of methanol-acetone (70%:30%. Chlorophyll extract dye was obtained after partition of the crude extracts in diethyl ether solution. Then, it was hydrolyzed under alkaline condition to get chlorophyllin. Xanthophyll was extracted from fresh petal of chrysanthemum (chrysanthemum indicum flowers. Blending of chlorophyllin and xanthophyll was carried out at various volume ratios of C to X (1:0, 5:1, 1:1, 1:5, 0:1. Titania solar cells were constructed in sandwich system of conducting glass-titania/dyes as the photoanode and conducting glass-platinum as the photocathode. Electrolyte solution containing I-/I3- was inserted between the electrodes by capillary action. All dye extracts and blending solutions were analyzed by UV-Vis spectrophotometer. It is shown that the absorption spectra of blending dyes are complimentary in the visible region resulted in a panchromatic response of the dyes. From the cyclic voltammogram of the dyes and blended-dyes, it is found that the energy level of xanthophyll is the lowest. The I-V test at 100 mw/cm2 irradiation confirmed that the energy conversion efficiency (h of the blended dyes of xanthophyll and chlorophyllin-sensitized solar cell resulted in significant improvement than those of the single dye. Beneficially, the mixed dyes can be adsorbed from solution blend using single dipping step.

  2. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Qin, J.-Z.; Xin, H. [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States); Nickoloff, B.J., E-mail: bnickol@lumc.edu [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States)

    2010-05-28

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.

  3. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines.

    Science.gov (United States)

    Qin, J-Z; Xin, H; Nickoloff, B J

    2010-05-28

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  4. 3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines

    International Nuclear Information System (INIS)

    Qin, J.-Z.; Xin, H.; Nickoloff, B.J.

    2010-01-01

    Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.

  5. Exploiting quantum interference in dye sensitized solar cells

    DEFF Research Database (Denmark)

    Maggio, Emanuele; Solomon, Gemma C.; Troisi, Alessandro

    2014-01-01

    A strategy to hinder the charge recombination process in dye sensitized solar cells is developed in analogy with similar approaches to modulate charge transport across nanostructures. The system studied is a TiO2 (anatase)-chromophore interface, with an unsaturated carbon bridge connecting the two...... of the possible tunnelling path. Calculations carried out on realistic molecules at the DFT level of theory show how the recombination lifetime can be modulated by changes in the electron-withdrawing (donating) character of the groups connected to the cross-conjugated bridge. Tight binding calculations...

  6. New Components for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Stefano Caramori

    2010-01-01

    Full Text Available Dye-Sensitized Solar Cells (DSSCs are among the most promising solar energy conversion devices of new generation, since coupling ease of fabrication and low cost offer the possibility of building integration in photovoltaic windows and facades. Although in their earliest configuration these systems are close to commercialization, fundamental studies are still required for developing new molecules and materials with more desirable properties as well as improving our understanding of the fundamental processes at the basis of the functioning of photoactive heterogeneous interfaces. In this contribution, some recent advances, made in the effort of improving DSSC devices by finding alternative materials and configurations, are reviewed.

  7. Novel nanostructures for next generation dye-sensitized solar cells

    KAUST Repository

    Tétreault, Nicolas

    2012-01-01

    Herein, we review our latest advancements in nanostructured photoanodes for next generation photovoltaics in general and dye-sensitized solar cells in particular. Bottom-up self-assembly techniques are developed to fabricate large-area 3D nanostructures that enable enhanced charge extraction and light harvesting through optical scattering or photonic crystal effects to improve photocurrent, photovoltage and fill factor. Using generalized techniques to fabricate specialized nanostructures enables specific optoelectronic and physical characteristics like conduction, charge extraction, injection, recombination and light harvesting but also helps improve mechanical flexibility and long-term stability in low cost materials. © 2012 The Royal Society of Chemistry.

  8. Weavable dye sensitized solar cells exploiting carbon nanotube yarns

    Science.gov (United States)

    Velten, Josef; Kuanyshbekova, Zharkynay; Göktepe, Özer; Göktepe, Fatma; Zakhidov, Anvar

    2013-05-01

    Weavable Dye Sensitized Solar Cells (DSSC) made with flexible yarns of conductive multiwalled carbon nanotubes (MWNTs) were produced having a power conversion efficiency above 3%. This was achieved with a specific design and careful consideration of the yarn function in the DSSC. Fermat yarns of MWNTs individually coated with mesoporous TiO2 layer were twisted together and coated with more mesoporous TiO2 to create a 3 dimensional photo electrode to overcome electron diffusion length issues. Archimedian yarns of MWNTs coated with a thin layer of platinum worked as a counter electrode to complete the architecture used in this DSSC.

  9. Intervention of oxygen-control ability to radiation sensitivity, cell aging and cell transformation

    International Nuclear Information System (INIS)

    Yoshii, Hanako; Watanabe, Masami

    2009-01-01

    Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions contributed to cellular lifespan and transformation. HE cells had their replicative lifespan slightly extended under hypoxic (0.5% and 2% oxygen) conditions, but were not immortalized under any of the oxygen concentrations. On the other hand, although ME cells cultured under 20% oxygen tension decreased their proliferation potency temporarily at early stage, all rodent cells were immortalized and acquired anchorage-independency, regardless of oxygen tension. These results suggest that cellular oxygen control function is related to sensitivities cellular immortalization and transformation. To understand intervention of oxygen control ability on cellular immortalization and transformation, we examined the intracellular oxidative level, mitochondria functions and radiation sensitivity. Intracellular oxidative levels of hypoxically cultured rodent cells were significantly enhanced. Mitochondrial membrane potential was altered depend on oxygen tensions, but the change was not parallel to mitochondria number in rodent cells. ME cells were particularly sensitive to oxygen change, and showed a clear oxygen effect on the X-ray survival. However, there was no difference in frequency of radiation-induced micronuclei between HE and ME cells. These results suggest that the response to oxygen change differs markedly in HE and rodent cells. (author)

  10. A new sensitive and quantitative HTLV-I-mediated cell fusion assay in T cells

    International Nuclear Information System (INIS)

    Pare, Marie-Eve; Gauthier, Sonia; Landry, Sebastien; Sun Jiangfeng; Legault, Eric; Leclerc, Denis; Tanaka, Yuetsu; Marriott, Susan J.; Tremblay, Michel J.; Barbeau, Benoit

    2005-01-01

    Similar to several other viruses, human T cell leukemia virus type I (HTLV-I) induces the formation of multinucleated giant cells (also known as syncytium) when amplified in tissue culture. These syncytia result from the fusion of infected cells with uninfected cells. Due to the intrinsic difficulty of infecting cells with cell-free HTLV-I virions, syncytium formation has become an important tool in the study of HTLV-I infection and transmission. Since most HTLV-I-based cell fusion assays rely on the use of non-T cells, the aim of this study was to optimize a new HTLV-I-induced cell fusion assay in which HTLV-I-infected T cell lines are co-cultured with T cells that have been transfected with an HTLV-I long terminal repeat (LTR) luciferase reporter construct. We demonstrate that co-culture of various HTLV-I-infected T cells with different transfected T cell lines resulted in induction of luciferase activity. Cell-to-cell contact and expression of the viral gp46 envelope protein was crucial for this induction while other cell surface proteins (including HSC70) did not have a significant effect. This quantitative assay was shown to be very sensitive. In this assay, the cell fusion-mediated activation of NF-κB and the HTLV-I LTR occurred through previously described Tax-dependent signaling pathways. This assay also showed that cell fusion could activate Tax-inducible cellular promoters. These results thus demonstrate that this new quantitative HTLV-I-dependent cell fusion assay is versatile, highly sensitive, and can provide an important tool to investigate cellular promoter activation and intrinsic signaling cascades that modulate cellular gene expression

  11. Gold leaf counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Shimada, Kazuhiro; Toyoda, Takeshi

    2018-03-01

    In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

  12. Solar cells with perovskite-based light sensitization layers

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Chang, Robert P.H.; Stoumpos, Konstantinos; Lee, Byunghong

    2018-05-08

    Solar cells are provided which comprise an electron transporting layer and a light sensitizing layer of perovskite disposed over the surface of the electron transporting layer. The perovskite may have a formula selected from the group consisting of A2MX6, Z2MX6 or YMX6, wherein A is an alkali metal, M is a metal or a metalloid, X is a halide, Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and Y has formula Mb(L)3, wherein Mb is a transition metal in the 2+ oxidation state L is an N--N neutral chelating ligand. Methods of making the solar cells are also provided, including methods based on electrospray deposition.

  13. PKC 412 sensitizes U1810 non-small cell lung cancer cells to DNA damage

    International Nuclear Information System (INIS)

    Hemstroem, Therese H.; Joseph, Bertrand; Schulte, Gunnar; Lewensohn, Rolf; Zhivotovsky, Boris

    2005-01-01

    Non-small cell lung carcinoma (NSCLC) is characterized by resistance to drug-induced apoptosis, which might explain the survival of lung cancer cells following treatment. Recently we have shown that the broad-range kinase inhibitor staurosporine (STS) reactivates the apoptotic machinery in U1810 NSCLC cells [Joseph et al., Oncogene 21 (2002) 65]. Lately, several STS analogs that are more specific in kinase inhibition have been suggested for tumor treatment. In this study the apoptosis-inducing ability of the STS analogs PKC 412 and Ro 31-8220 used alone or in combination with DNA-damaging agents in U1810 cells was investigated. In these cells Ro 31-8220 neither induced apoptosis when used alone, nor sensitized cells to etoposide treatment. PKC 412 as a single agent induced death of a small number of U1810 cells, whereas it efficiently triggered a dose- and time-dependent apoptosis in U1285 small cell lung carcinoma cells. In both cell types PKC 412 triggered release of mitochondrial proteins followed by caspase activation. However, concomitant activation of a caspase-independent pathway was essential to kill NSCLC cells. Importantly, PKC 412 was able to sensitize etoposide- and radiation-induced death of U1810 cells. The best sensitization was achieved when PKC 412 was administered 24 h after treatments. In U1810 cells, Ro 31-8220 decreased PMA-induced ERK phosphorylation as efficiently as PKC 412, indicating that the failure of Ro 31-8220 to induce apoptosis was not due to weaker inhibition of conventional and novel PKC isoforms. However, Ro 31-8220 increased the basal level of ERK and Akt phosphorylation in both cell lines, whereas Akt phosphorylation was suppressed in the U1810 cells, which might influence apoptosis. These results suggest that PKC 412 could be a useful tool in increasing the efficiency of therapy of NSCLC

  14. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.; Hoke, Eric T.; Armstrong, Paul B.; Yum, Jun-Ho; Comte, Pascal; Torres, Tomá s; Fré chet, Jean M. J.; Nazeeruddin, Md Khaja; Grä tzel, Michael; McGehee, Michael D.

    2009-01-01

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near

  15. PCM1 Depletion Inhibits Glioblastoma Cell Ciliogenesis and Increases Cell Death and Sensitivity to Temozolomide

    Directory of Open Access Journals (Sweden)

    Lan B. Hoang-Minh

    2016-10-01

    Full Text Available A better understanding of the molecules implicated in the growth and survival of glioblastoma (GBM cells and their response to temozolomide (TMZ, the standard-of-care chemotherapeutic agent, is necessary for the development of new therapies that would improve the outcome of current GBM treatments. In this study, we characterize the role of pericentriolar material 1 (PCM1, a component of centriolar satellites surrounding centrosomes, in GBM cell proliferation and sensitivity to genotoxic agents such as TMZ. We show that PCM1 is expressed around centrioles and ciliary basal bodies in patient GBM biopsies and derived cell lines and that its localization is dynamic throughout the cell cycle. To test whether PCM1 mediates GBM cell proliferation and/or response to TMZ, we used CRISPR/Cas9 genome editing to generate primary GBM cell lines depleted of PCM1. These PCM1-depleted cells displayed reduced AZI1 satellite protein localization and significantly decreased proliferation, which was attributable to increased apoptotic cell death. Furthermore, PCM1-depleted lines were more sensitive to TMZ toxicity than control lines. The increase in TMZ sensitivity may be partly due to the reduced ability of PCM1-depleted cells to form primary cilia, as depletion of KIF3A also ablated GBM cells' ciliogenesis and increased their sensitivity to TMZ while preserving PCM1 localization. In addition, the co-depletion of KIF3A and PCM1 did not have any additive effect on TMZ sensitivity. Together, our data suggest that PCM1 plays multiple roles in GBM pathogenesis and that associated pathways could be targeted to augment current or future anti-GBM therapies.

  16. Nanocrystalline dye-sensitized solar cells having maximum performance

    Energy Technology Data Exchange (ETDEWEB)

    Kroon, M.; Bakker, N.J.; Smit, H.J.P. [ECN Solar Energy, Petten (Netherlands); Liska, P.; Thampi, K.R.; Wang, P.; Zakeeruddin, S.M.; Graetzel, M. [LPI-ISIC, Ecole Polytechnique Federale de Lausanne EPFL, Station 6, CH-1015 Lausanne (Switzerland); Hinsch, A. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr.2, D-79110 Freiburg (Germany); Hore, S.; Wuerfel, U.; Sastrawan, R. [Freiburg Materials Research Centre FMF, Stefan-Meier Str. 21, 79104 Freiburg (Germany); Durrant, J.R.; Palomares, E. [Centre for Electronic Materials and Devices, Department of Chemistry, Imperial College London, Exhibition road SW7 2AY (United Kingdom); Pettersson, H.; Gruszecki, T. [IVF Industrial Research and Development Corporation, Argongatan 30, SE-431 53 Moelndal (Sweden); Walter, J.; Skupien, K. [Cracow University of Technology CUTECH, Jana Pawla II 37, 31-864 Cracow (Poland); Tulloch, G.E. [Greatcell Solar SA GSA, Ave Henry-Warnery 4, 1006 Lausanne (Switzerland)

    2007-01-15

    This paper presents an overview of the research carried out by a European consortium with the aim to develop and test new and improved ways to realise dye-sensitized solar cells (DSC) with enhanced efficiencies and stabilities. Several new areas have been explored in the field of new concepts and materials, fabrication protocols for TiO2 and scatterlayers, metal oxide blocking layers, strategies for co-sensitization and low temperature processes of platinum deposition. Fundamental understanding of the working principles has been gained by means of electrical and optical modelling and advanced characterization techniques. Cost analyses have been made to demonstrate the potential of DSC as a low cost thin film PV technology. The combined efforts have led to maximum non-certified power conversion efficiencies under full sunlight of 11% for areas <0c2 cm{sup 2} and 10c1% for a cell with an active area of 1c3 cm{sup 2}. Lifetime studies revealed negligible device degradation after 1000 hrs of accelerated tests under thermal stress at 80C in the dark and visible light soaking at 60C. An outlook summarizing future directions in the research and large-scale production of DSC is presented.

  17. Pt-graphene electrodes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Hoshi, Hajime; Tanaka, Shumpei; Miyoshi, Takashi

    2014-01-01

    Highlights: • Graphene films with Pt nanoparticles were prepared from commercial graphene. • Pt consumption can be reduced by using Pt-graphene films. • The film showed improved catalytic activity for the reaction I 3 − /I − . • The film can be used as the counter electrode of dye-sensitized solar cells (DSSCs). • The performance of DSSC was superior to that of the Pt electrode. - Abstract: A simple paste method for fabricating graphene films with Pt nanoparticles was developed. First, graphene pastes with Pt nanoparticles were prepared from commercially available graphene. The resulting films of graphene nanoplatelet aggregates with Pt nanoparticles (Pt-GNA) contained Pt nanoparticles distributed over the entire three-dimensional surface of the GNA. Then, the catalytic activity for the I 3 − /I − redox reaction was evaluated by cyclic voltammetry. The GNA electrode exhibited higher activity than a graphene nanoplatelet electrode because of its higher effective surface area. Addition of Pt nanoparticles to the electrodes improved the catalytic activity. In particular, a large Faradaic current for the I 3 − /I − reaction was observed for the Pt-GNA electrode. As the counter electrodes of dye-sensitized solar cells (DSSCs), their performance was consistent with the cyclic voltammetry results. In particular, the DSSC performance of the Pt-GNA electrode was superior to that of the Pt electrodes commonly used in DSSCs

  18. Artificial evolution of coumarin dyes for dye sensitized solar cells.

    Science.gov (United States)

    Venkatraman, Vishwesh; Abburu, Sailesh; Alsberg, Bjørn Kåre

    2015-11-07

    The design and discovery of novel molecular structures with optimal properties has been an ongoing effort for materials scientists. This field has in general been dominated by experiment driven trial-and-error approaches that are often expensive and time-consuming. Here, we investigate if a de novo computational design methodology can be applied to the design of coumarin-based dye sensitizers with improved properties for use in Grätzel solar cells. To address the issue of synthetic accessibility of the designed compounds, a fragment-based assembly is employed, wherein the combination of chemical motifs (derived from the existing databases of structures) is carried out with respect to user-adaptable set of rules. Rather than using computationally intensive density functional theory (DFT)/ab initio methods to screen candidate dyes, we employ quantitative structure-property relationship (QSPR) models (calibrated from empirical data) for rapid estimation of the property of interest, which in this case is the product of short circuit current (Jsc) and open circuit voltage (Voc). Since QSPR models have limited validity, pre-determined applicability domain criteria are used to prevent unacceptable extrapolation. DFT analysis of the top-ranked structures provides supporting evidence of their potential for dye sensitized solar cell applications.

  19. Radiolabeled cypoxic cell sensitizers: tracer for assessment of ischemia

    International Nuclear Information System (INIS)

    Mathias, C.J.; Welch, M.J.; Kilbourn, M.R.; Jerabek, P.A.; Patrick, T.B.; Raichle, M.E.; Krohn, K.A.; Rasey, J.S.; Shaw, D.W.

    1987-01-01

    Hypoxic, non-functional, but viable, tissue may exist in heart and brain following an arterial occlusion. Identification of such tissue in vivo is crucial to the development of effective treatment strategies. It has been suggested that certain compounds capable of sensitizing hypoxic tumor cells to killing by x-rays (i.e., misonidazole) might serve as in vivo markers of hypoxic tissue in ischemic myocardium or brain if properly radiolabeled. To this end the authors have radiolabeled two fluorinated analogs of nitroimidazole based hypoxic cell sensitizers with the 110 minute half-lived positron-emitting fluorine-18. The ability of these tracers to quantitate the presence of hypoxic tissue has been studied in a gerbil stroke model. The in vivo uptake of one of these tracers [F-18]-fluoronormethyoxymisonidazole is dependent on the extent of tissue hypoxia, and thus, appears to have potential as a diagnostic indicator of non-functional but viable tissue when the tracer is used in conjunction with positron emission tomography. 80 references, 2 figures, 1 table

  20. Pt-graphene electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Hajime, E-mail: hoshi@ed.tus.ac.jp; Tanaka, Shumpei; Miyoshi, Takashi

    2014-12-15

    Highlights: • Graphene films with Pt nanoparticles were prepared from commercial graphene. • Pt consumption can be reduced by using Pt-graphene films. • The film showed improved catalytic activity for the reaction I{sub 3}{sup −}/I{sup −}. • The film can be used as the counter electrode of dye-sensitized solar cells (DSSCs). • The performance of DSSC was superior to that of the Pt electrode. - Abstract: A simple paste method for fabricating graphene films with Pt nanoparticles was developed. First, graphene pastes with Pt nanoparticles were prepared from commercially available graphene. The resulting films of graphene nanoplatelet aggregates with Pt nanoparticles (Pt-GNA) contained Pt nanoparticles distributed over the entire three-dimensional surface of the GNA. Then, the catalytic activity for the I{sub 3}{sup −}/I{sup −} redox reaction was evaluated by cyclic voltammetry. The GNA electrode exhibited higher activity than a graphene nanoplatelet electrode because of its higher effective surface area. Addition of Pt nanoparticles to the electrodes improved the catalytic activity. In particular, a large Faradaic current for the I{sub 3}{sup −}/I{sup −} reaction was observed for the Pt-GNA electrode. As the counter electrodes of dye-sensitized solar cells (DSSCs), their performance was consistent with the cyclic voltammetry results. In particular, the DSSC performance of the Pt-GNA electrode was superior to that of the Pt electrodes commonly used in DSSCs.

  1. Cell surface GRP78 facilitates hepatoma cells proliferation and migration by activating IGF-IR.

    Science.gov (United States)

    Yin, Yancun; Chen, Chen; Chen, Jinliang; Zhan, Renhui; Zhang, Qiang; Xu, Xiaoyan; Li, Defang; Li, Minjing

    2017-07-01

    The 78kDa glucose regulated protein (GRP78) is a multifunctional chaperone that is involved in a variety of cellular processes. Insulin like growth factor I receptor (IGF-IR) often aberrant expresses in many types of tumor cells. The IGF-IR signaling plays key roles in carcinogenesis and maintenance of the malignant phenotype. The crosstalk between GRP78 and IGF-IR molecules has not well been illuminated. Here, we demonstrated a reciprocal regulation of GRP78 expression and IGF-IR pathway activation. IGF-I induced GRP78 expression in hepatoma cells. IGF-IR knockdown or IGF-IR inhibitor repressed GRP78 expression. Both phosphatidylinositol 3-kianase (PI3K) and mitogen-activated protein kinase (MAPK) pathways involved in IGF-I induction of GRP78 expression. Interestingly, treatment of hepatoma cells with IGF-I re-distributes GRP78 from endoplasmic reticulum (ER) to cell surface and promotes its physical interaction with IGF-IR. Also, GRP78 promotes IGF-IR phosphorylation and activation. Blocked of GRP78 by small interfering RNA or inhibition of GRP78 function by (-)-epigallocatechin gallate (EGCG) blocks IGF-I induced IGF-IR phosphorylation and its downstream signaling. Further, blocked cell surface GRP78 with antibody inhibits IGF-I stimulated cellular proliferation and migration. These data reveal an essential role for the molecular chaperone GRP78 in IGF-IR signaling and implicate the use of GRP78 inhibitors in blocking IGF-IR signaling in hepatoma cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Dye-sensitized solar cells using Aloe Vera and Cladode of Cactus extracts as natural sensitizers

    Science.gov (United States)

    Ganta, D.; Jara, J.; Villanueva, R.

    2017-07-01

    The purpose of this study is to develop dye-sensitized solar cells (DSSCs) from natural plant-based dyes, extracted from the Cladode (nopal) of the Thornless Prickly Pear Cactus (Opuntia ficus-indica), the gel of Aloe Vera (Aloe barbadensis miller), and the combination of Cladode and Aloe Vera extracts on side-by-side configuration. Optical properties were analyzed using UV-Vis Absorption and Fourier Transform Infrared Spectroscopy. Open circuit voltages (Voc) varied from 0.440 to 0.676 V, fill factors (FF) were greater than 40%, short-circuit photocurrent densities (Jsc) ranged from 0.112 to 0.290 mA/cm2 and highest conversion efficiency of 0.740% was reported for the Cladode DSSC.

  3. Dye-sensitized solar cells using natural dyes as sensitizers from Malaysia local fruit `Buah Mertajam'

    Science.gov (United States)

    Hambali, N. A. M. Ahmad; Roshidah, N.; Hashim, M. Norhafiz; Mohamad, I. S.; Saad, N. Hidayah; Norizan, M. N.

    2015-05-01

    We experimentally demonstrate the high conversion efficiency, low cost, green technology and easy to fabricate dye-sensitized solar cells (DSSCs) using natural anthocyanin dyes as sensitizers. The DSSCs was fabricated by using natural anthocyanin dyes which were extracted from different parts of the plants inclusive `Buah Mertajam', `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. The natural anthocyanin dyes that found in flower, leaves and fruits were extracted by the simple procedures. This anthocyanin dye is used to replace the expensive chemical synthetic dyes due to its ability to effectively attach into the surface of Titanium dioxide (TiO2). A natural anthocyanin dyes molecule adsorbs to each particle of the TiO2 and acts as the absorber of the visible light. A natural anthocyanin dye from Buah Mertajam shows the best performance with the conversion efficiency of 5.948% and fill factor of 0.708 followed by natural anthocyanin dyes from `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. Buah Mertajam or scientifically known as eriglossum rubiginosum is a local Malaysia fruit.

  4. Solution Processed Silver Nanoparticles in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Marko Berginc

    2014-01-01

    Full Text Available A plasmonic effect of silver nanoparticles (Ag NPs in dye-sensitized solar cells (DSSCs is studied. The solutions of silver nitrate in isopropanol, ethylene glycol, or in TiO2 sol were examined as possible precursors for Ag NPs formation. The solutions were dip-coated on the top of the porous TiO2 layer. The results of optical measurements confirmed the formation of Ag NPs throughout the porous TiO2 layer after the heat treatment of the layers above 100°C. Heat treatment at 220°C was found to be optimal regarding the formation of the Ag NPs. The porous TiO2 layers with Ag NPs have been evaluated also in DSSC by measuring current-voltage characteristics and the external quantum efficiency of the cells. In addition, the amount of adsorbed dye has been determined to prove the plasmonic effect in the cells. The I-V characterization of the DSSCs revealed an increase of the short circuit current in the presence of Ag NPs although the amount of the attached dye molecules decreased. These results confirm that the performance enhancement is related to the plasmonic effect. However, neither a thin sol-gel TiO2 layer nor poly(4-vinylpyridine shells provide effective protection for the long term stability of the Ag NPs against the corrosion of I3-/I- based electrolyte.

  5. Photovoltaic characteristics of natural light harvesting dye sensitized solar cells

    Science.gov (United States)

    Hafez, H. S.; Shenouda, S. S.; Fadel, M.

    2018-03-01

    In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO2 nanoparticles with an average particle size (10-40 nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100 mW.cm- 2. The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R = 15.6-23.8 mA.W- 1 and η = 0.13-0.25) at AM = 1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology.

  6. Photovoltaic characteristics of natural light harvesting dye sensitized solar cells.

    Science.gov (United States)

    Hafez, H S; Shenouda, S S; Fadel, M

    2018-03-05

    In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO 2 nanoparticles with an average particle size (10-40nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO 2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100mW.cm -2 . The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R=15.6-23.8mA.W -1 and η=0.13-0.25) at AM=1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Evalation of a radioimmunoassay for somatomedin-C/insulin-like growth factor I (Sm-C/IGF-I) in human plasma

    International Nuclear Information System (INIS)

    Giannella-Neto, D.; Cavaleiro, A.M.; Wajchenberg, B.L.; Sadoyama, R.; Spencer, E.M.

    1990-01-01

    In the present report the authors describe the development of a very sensitive radioimmunoassay for the quantitativew determination of human somatomedin-C/insulin-like growth factor I in plasma samples extracted by an acid-ethanol procedure. (RB). 22 refs.; 1 fig.; 1 tab

  8. Immune suppression with supraoptimal doses of antigen in contact sensitivity. I. Demonstration of suppressor cells and their sensitivity to cyclophosphamide.

    Science.gov (United States)

    Sy, M S; Miller, S D; Claman, H N

    1977-07-01

    Immunologic suppression was induced in a mouse model of contact sensitization to DNFB by using supraoptimal doses of antigen. In these studies, in vivo measurement of ear swelling as an indication of immunologic responsiveness correlated well with measurement of in vitro antigen-induced cell proliferation. This unresponsiveness was specific, since supraoptimal doses of DNFB did not interfere with the development of contact sensitivity to another contactant, oxazolone. The decrease in responsiveness is a form of active suppression, as lymphoid cells from supraoptimally sensitized donors transferred suppression to normal recipients. Furthermore, pretreatment with cyclophosphamide (Cy) reversed the suppression seen in supraoptimally sensitized animals but had no effect on the optimal sensitization regimen. These results indicate that supraoptimal doses of contactants can activate suppressor cells and that precursors of these cells are sensitive to Cy. Such suppressors regenerate within 7 to 14 days after Cy treatment. The ability of Cy pretreatment to affect supraoptimal sensitization without affecting optimal sensitization confirms other reports indicating that the observed results of Cy treatment depend critically upon the dose of antigen used.

  9. Recent advances in plasmonic dye-sensitized solar cells

    Science.gov (United States)

    Rho, Won-Yeop; Song, Da Hyun; Yang, Hwa-Young; Kim, Ho-Sub; Son, Byung Sung; Suh, Jung Sang; Jun, Bong-Hyun

    2018-02-01

    Dye-sensitized solar cells (DSSCs) are among the best devices in generating electrons from solar light energy due to their high efficiency, low-cost in processing and transparency in building integrated photovoltaics. There are several ways to improve their energy-conversion efficiency, such as increasing light harvesting and electron transport, of which plasmon and 3-dimensional nanostructures are greatly capable. We review recent advances in plasmonic effects which depend on optimizing sizes, shapes, alloy compositions and integration of metal nanoparticles. Different methods to integrate metal nanoparticles into 3-dimensional nanostructures are also discussed. This review presents a guideline for enhancing the energy-conversion efficiency of DSSCs by utilizing metal nanoparticles that are incorporated into 3-dimensional nanostructures.

  10. Dye Sensitized Solar Cells for Economically Viable Photovoltaic Systems.

    Science.gov (United States)

    Jung, Hyun Suk; Lee, Jung-Kun

    2013-05-16

    TiO2 nanoparticle-based dye sensitized solar cells (DSSCs) have attracted a significant level of scientific and technological interest for their potential as economically viable photovoltaic devices. While DSSCs have multiple benefits such as material abundance, a short energy payback period, constant power output, and compatibility with flexible applications, there are still several challenges that hold back large scale commercialization. Critical factors determining the future of DSSCs involve energy conversion efficiency, long-term stability, and production cost. Continuous advancement of their long-term stability suggests that state-of-the-art DSSCs will operate for over 20 years without a significant decrease in performance. Nevertheless, key questions remain in regards to energy conversion efficiency improvements and material cost reduction. In this Perspective, the present state of the field and the ongoing efforts to address the requirements of DSSCs are summarized with views on the future of DSSCs.

  11. Nonislet Cell Tumor Hypoglycemia in a Patient with Adrenal Cortical Carcinoma

    Directory of Open Access Journals (Sweden)

    Se Won Kim

    2016-01-01

    Full Text Available Nonislet cell tumor hypoglycemia (NICTH is a rare but serious paraneoplastic syndrome in which a tumor secretes incompletely processed precursors of insulin-like growth factor-II (IGF-II, causing hypoglycemia. Here, we report an exceptional case of NICTH caused by nonfunctioning adrenocortical carcinoma in a 39-year-old male with recurrent hypoglycemia. The patient’s serum IGF-II/IGF-I ratio had increased to 27.8. The serum level of the IGF-II/IGF-I ratio was normalized after removal of the tumor, and the hypoglycemic attacks no longer occurred after the operation.

  12. Age and radiation sensitivity of rat mammary clonogenic cells

    International Nuclear Information System (INIS)

    Shimada, Yoshiya; Yasukawa-Barnes, J.; Kim, R.Y.; Gould, M.N.; Clifton, K.H.

    1994-01-01

    The relative risk of breast cancer is very high among women who were exposed to ionizing radiation during or before puberty. In the current studies, the surviving fractions of clonogenic mammary cells of groups of virgin rats were estimated after single exposures to 137 Cs γ rays at intervals from 1 to 12 weeks after birth. The radiosensitivity of clonogens from prepubertal rats was high and changed with the onset of puberty at between 4 and 6 weeks of age. By this time, the increase in the size of the clonogenic cell subpopulation was slowing and differentiation of terminal mammary end buds and alveolar structures was occurring. Analysis of the relationship of clonogen survival and radiation dose according to the α/β model showed that the exponential αD term predominated at the second and fourth weeks of age. By the eighth week of age, the βD 2 term had come to predominate and the survival curve had a pronounced initial convex shoulder. Further experiments are required to determine whether there is an association between the high sensitivity of the prepubertal and pubertal mammary clonogens to radiation killing and a high susceptibility to radiogenic initiation of cancer. 24 refs., 4 figs., 1 tab

  13. Antiangiogenic Agent Might Upgrade tumor Cell Sensitivity to Ionizing Radiation

    International Nuclear Information System (INIS)

    Badr, N.M.S.A.

    2013-01-01

    The understanding of the fundamental role of angiogenesis and metastasis in cancer growth has led to tremendous interest in research regarding its regulatory mechanisms and clinical implications in the management of cancer. The present study was conducted to evaluate the influence of the angiogenic regulators modification on the tumor growth and the cell sensitivity to ionizing radiation targeting the improvement of cancer therapeutic protocols. Accordingly, the antiangiogenic activity of apigenin and selenium was tested in vitro via MTT assay. The action of Apigenin and or Selenium was examined in vivo by using a model of solid tumor carcinoma (EAC). The growth rate of solid tumor in all experimental groups was measured by Caliper. The irradiated mice were exposed to 6.5 Gy of gamma rays. Apigenin 50 mg/kg body weight and selenium 5 μg per mice were daily administrated for 14 consecutive days after tumor volume reached 1mm 3 . The angiogenic activators TNF-α (key cytokine) in spleen, serum MMP 2 and MMP 9, liver and tumor NO, the lipid peroxidation (LPx) and angiogenic inhibitor TIMP-1 in spleen as well as, antioxidant markers (CAT, SOD, GPX) in tumor and liver tissue and DNA fragmentation in splenocytes were estimated to monitor efficacy of Apigenin and selenium in cancer treatment strategy. All parameters were determined as a time course on days 16 and 22 after tumor volume reached 1mm 3 . The using of MTT assay on EAC cells shows inhibition in EAC cell proliferation after the incubation with apigenin and /or selenium. The administration of apigenin and /or selenium to mice bearing tumor and to irradiated mice bearing tumor reduce significantly the TNF-α expression, MMP 2,9 , NO , LPx level and increased the antioxidant enzymes (GPx , SOD and CAT) activities. The DNA fragmentation and the antiangiogenic factors TIMP-1 were significantly increased when compared with their values in mice bearing tumor or in irradiated mice bearing tumor. From the results

  14. β-Catenin/POU5F1/SOX2 transcription factor complex mediates IGF-I receptor signaling and predicts poor prognosis in lung adenocarcinoma.

    Science.gov (United States)

    Xu, Chuan; Xie, Dan; Yu, Shi-Cang; Yang, Xiao-Jun; He, Li-Ru; Yang, Jing; Ping, Yi-Fang; Wang, Bin; Yang, Lang; Xu, Sen-Lin; Cui, Wei; Wang, Qing-Liang; Fu, Wen-Juan; Liu, Qing; Qian, Cheng; Cui, You-Hong; Rich, Jeremy N; Kung, Hsiang-Fu; Zhang, Xia; Bian, Xiu-Wu

    2013-05-15

    Cancer stem-like cells (CSLC) are crucial in tumor initiation and progression; however, the underlying mechanism for the self-renewal of cancer cells remains undefined. In the study, immunohistochemical analysis of specimens freshly excised from patients with lung adenocarcinoma showed that high expression of insulin-like growth factor I receptor (IGF-IR) in lung adenocarcinoma cells was positively correlated with the expressions of cancer stem cell markers CD133 and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). IGF-IR activation enhanced POU class 5 homeobox 1 (POU5F1) expression on human lung adenocarcinoma stem-like cells (LACSLC) through PI3K/AKT/GSK3β/β-catenin cascade. POU5F1 could form a novel complex with β-catenin and SOX2 to bind Nanog promoter for transcription to maintain self-renewal of LACSLCs, which was dependent on the functional IGF-IR. Genetic and pharmacologic inhibition of IGF-IR abrogated LACSLC capabilities for self-renewal and tumorigenicity in vitro. In an in vivo xenograft tumor model, knockdown of either IGF-IR or POU5F1 impeded tumorigenic potentials of LACSLCs. By analyzing pathologic specimens excised from 200 patients with lung adenocarcinoma, we found that colocalization of highly expressed IGF-IR with β-catenin and POU5F1 predicted poor prognosis. Taken together, we show that IGF-IR-mediated POU5F1 expression to form a complex with β-catenin and SOX2 is crucial for the self-renewal and oncogenic potentials of LACSLCs, and the integrative clinical detection of the expressions of IGF-IR, β-catenin, and POU5F1 is indicatory for predicting prognosis in the patients of lung adenocarcinoma. ©2013 AACR.

  15. Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

    LENUS (Irish Health Repository)

    Doherty, Ben

    2014-01-01

    KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer.

  16. Paris Saponin I Sensitizes Gastric Cancer Cell Lines to Cisplatin via Cell Cycle Arrest and Apoptosis.

    Science.gov (United States)

    Song, Shuichuan; Du, Leiwen; Jiang, Hao; Zhu, Xinhai; Li, Jinhui; Xu, Ji

    2016-10-18

    BACKGROUND Dose-related toxicity is the major restriction of cisplatin and cisplatin-combination chemotherapy, and is a challenge for advanced gastric cancer treatment. We explored the possibility of using Paris saponin I as an agent to sensitize gastric cancer cells to cisplatin, and examined the underlying mechanism. MATERIAL AND METHODS Growth inhibition was detected by MTT assay. The cell cycle and apoptosis were detected using flow cytometry and Annexin V/PI staining. The P21waf1/cip1, Bcl-2, Bax, and caspase-3 protein expression were detected using Western blot analysis. RESULTS The results revealed that PSI sensitized gastric cancer cells to cisplatin, with low toxicity. The IC50 value of cisplatin in SGC-7901 cell lines was decreased when combined with PSI. PSI promoted cisplatin-induced G2/M phase arrest and apoptosis in a cisplatin concentration-dependent manner. Bcl-2 protein expression decreased, but Bax, caspase-3, and P21waf1/cip1 protein expression increased with PSI treatment. CONCLUSIONS The underlying mechanism of Paris saponin I may be related to targeting the apoptosis pathway and cell cycle blocking, which suggests that PSI is a potential therapeutic sensitizer for cisplatin in treating gastric cancer.

  17. Y-27632 Increases Sensitivity of PANC-1 Cells to EGCG in Regulating Cell Proliferation and Migration.

    Science.gov (United States)

    Liu, Xing; Bi, Yongyi

    2016-10-03

    BACKGROUND The study aimed to investigate the inhibitory effect of (1R,4r)-4-((R)-1-aminoethyl)-N-(pyridin-4-yl) cyclohexanecarboxamide (Y-27632) and (-)-epigallocatechin-3-gallate (EGCG) on the proliferation and migration of PANC-1 cells. EGCG, found in green tea, has been previously shown to be one of the most abundant and powerful catechins in cancer prevention and treatment. Y-27632, a selective inhibitor of rho-associated protein kinase 1, is widely used in treating cardiovascular disease, inflammation, and cancer. MATERIAL AND METHODS PANC-1 cells, maintained in Dulbecco's Modified Eagle's Medium, were treated with dimethyl sulfoxide (control) as well as different concentrations (20, 40, 60, and 80 μg/mL) of EGCG for 48 h. In addition, PANC-1 cells were treated separately with 60 μg/mL EGCG, 20 μM Y-27632, and EGCG combined with Y-27632 (60 μg/mL EGCG + 20 μM Y-27632) for 48 h. The effect of EGCG and Y-27632 on the proliferation and migration of PANC-1 cells was evaluated using Cell Counting Kit-8 and transwell migration assays. The expression of peroxisome proliferator-activated receptor alpha (PPARα) and Caspase-3 mRNA was determined by Quantitative real-time polymerase chain reaction (RT-qPCR). RESULTS EGCG (20-80 μg/mL) inhibited cell viability in a dose-dependent manner. Y-27632 enhanced the sensitivity of PANC-1 cells to EGCG (by increasing the expression of PPARa and Caspase-3 mRNA) and suppressed cell proliferation. PANC-1 cell migration was inhibited by treatment with a combination of EGCG and Y-27632. CONCLUSIONS Y-27632 increases the sensitivity of PANC-1 cells to EGCG in regulating cell proliferation and migration, which is likely to be related to the expression of PPARa mRNA and Caspase-3 mRNA.

  18. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae-Hee, E-mail: leedneo@gmail.com [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Kim, Dong-Wook [Department of Microbiology, Immunology, and Cancer Biology, University of VA (United States); Jung, Chang-Hwa [Division of Metabolism and Functionality Research, Korea Food Research Institute (Korea, Republic of); Lee, Yong J. [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Park, Daeho, E-mail: daehopark@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-09-15

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway.

  19. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    International Nuclear Information System (INIS)

    Lee, Dae-Hee; Kim, Dong-Wook; Jung, Chang-Hwa; Lee, Yong J.; Park, Daeho

    2014-01-01

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway

  20. Diffusion Length Mapping for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Lucio Cinà

    2016-08-01

    Full Text Available The diffusion length (L of photogenerated carriers in the nanoporous electrode is a key parameter that summarizes the collection efficiency behavior in dye-sensitized solar cells (DSCs. At present, there are few techniques able to spatially resolve L over the active area of the device. Most of them require contact patterning and, hence, are intrinsically destructive. Here, we present the first electron diffusion length mapping system for DSCs based on steady state incident photon to collected electron (IPCE conversion efficiency ( η I P C E analysis. The measurement is conducted by acquiring complete transmittance ( T DSC and η I P C E spectra from the photo electrode (PE and counter electrode (CE for each spatial point in a raster scan manner. L ( x , y is obtained by a least square fitting of the IPCE ratio spectrum ( I P C E R = η I P C E -CE η I P C E -PE . An advanced feature is the ability to acquire η I P C E spectra using low-intensity probe illumination under weakly-absorbed background light (625 nm with the device biased close to open circuit voltage. These homogeneous conditions permit the linearization of the free electron continuity equation and, hence, to obtain the collection efficiency expressions ( η COL-PE and η COL-CE . The influence of the parameter’s uncertainty has been quantified by a sensitivity study of L. The result has been validated by quantitatively comparing the average value of L map with the value estimated from electrochemical impedance spectroscopy (EIS.

  1. Isolation of UV-sensitive mutants of mouse L5178Y cells by a cell suspension spotting method

    International Nuclear Information System (INIS)

    Shiomi, T.; Hieda-Shiomi, N.; Sato, K.

    1982-01-01

    We have isolated 56 UV-sensitive mutant clones from a mouse L51 T/t line of L5178Y cells by a cell suspension spotting method. Five mutants have also been isolated from L51 T/t and L5178Y cells by the method reported by Thompson and coworkers. We divided the mutants into two groups, highly sensitive and moderately sensitive mutants, according to their sensitivity to UV irradiation. Fifty-eight mutants were highly sensitive and three were moderately sensitive to UV. The reconstruction experiments indicate that more than 90% of highly sensitive mutants were recovered by the cell suspension spotting method. Frequencies of recovered mutants highly sensitive to UV increased with increasing dose of mutagens. Recovered mutant frequency reached 10(-2) after treatment with 1.5 micrograms/ml of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) (survival 0.2%). Eight UV-sensitive mutants were divided into four complementation groups. These mutants were 2-6 times more sensitive to UV than parental L51 T/t cells in terms of D37 (dose required to reduce survival to 37%). Four representative UV-sensitive mutants which are classified into different complementation groups were examined for their sensitivity to killing by UV, 4-nitroquinoline-1-oxide (4NQO), mitomycin C (MMC), X-rays, and MNNG. All four classes of mutants were found to be cross-sensitive to UV, 4NQO, and MMC, but not sensitive to X-rays and MNNG

  2. Organic dye for highly efficient solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt-Mende, L.; Bach, U.; Humphry-Baker, R.; Ito, S.; Graetzel, M. [Institut des Sciences et Ingenierie Chimiques (ISIC), Laboratoire de Photonique et Interfaces (LPI), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Horiuchi, T.; Miura, H. [Technology Research Laboratory, Corporate Research Center, Mitsubishi Paper Mills Limited, 46, Wadai, Tsukuba City, Ibaraki 300-4247 (Japan); Uchida, S. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1-1 Katahira 2-chome, Aoba-ku, Sendai 980-8577 (Japan)

    2005-04-04

    The feasibility of solid-state dye-sensitized solar cells as a low-cost alternative to amorphous silicon cells is demonstrated. Such a cell with a record efficiency of over 4 % under simulated sunlight is reported, made possible by using a new organic metal-free indoline dye as the sensitizer with high absorption coefficient. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  3. Relationship between sensitivity to ultraviolet light and budding in yeast cells of different culture ages

    International Nuclear Information System (INIS)

    Atsuta, J.; Okajima, S.

    1976-01-01

    Subpopulations of yeast cells, consisting of cells of different sizes and different percentages of budding cells, were prepared by centrifugation through sucrose solutions with linear density gradients of cultures at different phases of the growth cycle. Ultraviolet survival of these cells was determined by colony counting, and the survival rate was compared with the cells' respiratory rates. Individual budding cells and interdivisional cells, and also mother cells and daughter cells derived from irradiated budding cells, were isolated by the micromanipulation technique. The number of divisions in each cell was measured during a 21-hr incubation period immediately after irradiation. In the population in the logarithmic phase consisting of homogeneous cells of middle size, no difference in uv sensitivity was observed between mother cells and daughter cells, irrespective of mutual adhesion. Budding cell resistance was observed in the population in the transitional phase; this was due to the lesser uv sensitivity of daughter cells in the fresh medium. In the stationary phase, daughter cells were rather more sensitive than mother cells or interdivisional cells, so there was little difference in uv sensitivity between budding cells and interdivisional cells

  4. Pomegranate leaves and mulberry fruit as natural sensitizers for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ho; Lo, Yu-Jen [Department of Mechanical Engineering, National Taipei University of Technology (China)

    2010-10-15

    This study employs chlorophyll extract from pomegranate leaf and anthocyanin extract from mulberry fruit as the natural dyes for a dye-sensitized solar cell (DSSC). A self-developed nanofluid synthesis system is employed to prepare TiO{sub 2} nanofluid with an average particle size of 25 nm. Electrophoresis deposition was performed to deposit TiO{sub 2} nanoparticles on the indium tin oxide (ITO) conductive glass, forming a TiO{sub 2} thin film with the thickness of 11 {mu}m. Furthermore, this TiO{sub 2} thin film was sintered at 450 C to enhance the thin film compactness. Sputtering was used to prepare counter electrode by depositing Pt thin film on FTO glass at a thickness of 20 nm. The electrodes, electrolyte (I{sub 3}{sup -}), and dyes were assembled into a cell module and illuminated by a light source simulating AM 1.5 with a light strength of 100 mW/cm{sup 2} to measure the photoelectric conversion efficiency of the prepared DSSCs. According to experimental results, the conversion efficiency of the DSSCs prepared by chlorophyll dyes from pomegranate leaf extract is 0.597%, with open-circuit voltage (V{sub OC}) of 0.56 V, short-circuit current density (J{sub SC}) of 2.05 mA/cm{sup 2}, and fill factor (FF) of 0.52. The conversion efficiency of the DSSCs prepared by anthocyanin dyes from mulberry extract is 0.548%, with V{sub OC} of 0.555 V and J{sub SC} of 1.89 mA/cm{sup 2} and FF of 0.53. The conversion efficiency is 0.722% for chlorophyll and anthocyanin as the dye mixture, with V{sub OC} of 0.53 V, J{sub SC} of 2.8 mA/cm{sup 2}, and FF of 0.49. (author)

  5. Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death

    International Nuclear Information System (INIS)

    Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki

    2006-01-01

    Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated

  6. Numerical Procedure for Optimizing Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mihai Razvan Mitroi

    2014-01-01

    Full Text Available We propose a numerical procedure consisting of a simplified physical model and a numerical method with the aim of optimizing the performance parameters of dye-sensitized solar cells (DSSCs. We calculate the real rate of absorbed photons (in the dye spectral range Grealx by introducing a factor β<1 in order to simplify the light absorption and reflection on TCO electrode. We consider the electrical transport to be purely diffusive and the recombination process only to occur between electrons from the TiO2 conduction band and anions from the electrolyte. The used numerical method permits solving the system of differential equations resulting from the physical model. We apply the proposed numerical procedure on a classical DSSC based on Ruthenium dye in order to validate it. For this, we simulate the J-V characteristics and calculate the main parameters: short-circuit current density Jsc, open circuit voltage Voc, fill factor FF, and power conversion efficiency η. We analyze the influence of the nature of semiconductor (TiO2 and dye and also the influence of different technological parameters on the performance parameters of DSSCs. The obtained results show that the proposed numerical procedure is suitable for developing a numerical simulation platform for improving the DSSCs performance by choosing the optimal parameters.

  7. Photo Degradation in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    T. J. Abodunrin

    2015-05-01

    Full Text Available Mesoporous TiO2 of 20nm diameter is prepared in-tandem with organic dyes and based on Fluorine –doped SnO2 (FTO, conducting base is produced by hydrothermal process. The prepared mesoporous Cola Acuminata (C.acuminata, Lupinus Arboreus (L.arboreus and Bougainvillea Spectabilis (B.spectabilis films (0.16 cm2 are applied; individually and in combination as interfacial layer in-between nanocrystalline TiO2 (NC- TiO2 and the FTO anode in the dye-sensitized solar cell (DSSC. Absorbance index (A.I of all three dyes was studied within wavelength range 200-900 nm for a period of 11 months, equivalent to 352 sun exposure. C.acuminata had A.I value 4.00 that decreased to 2.32 under exposure to AM1.5 global conditions. B.spectabilis A.I was 1.19 but decreased to 0.520 within same period of study. Combination of C.acuminata and B.spectabilis gave A.I value 1.40, dye cocktails of C.acuminata, B.spectabilis and L.arboreus gave 2.00 A.I value for same wavelength range. A UV/Vis photo spectrometer was used to determine the prominent peaks and absorbance at such wavelengths. This exponential relationship is subject of our explorative study.

  8. Nanostructured Semiconductor Materials for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Carmen Cavallo

    2017-01-01

    Full Text Available Since O’Regan and Grätzel’s first report in 1991, dye-sensitized solar cells (DSSCs appeared immediately as a promising low-cost photovoltaic technology. In fact, though being far less efficient than conventional silicon-based photovoltaics (being the maximum, lab scale prototype reported efficiency around 13%, the simple design of the device and the absence of the strict and expensive manufacturing processes needed for conventional photovoltaics make them attractive in small-power applications especially in low-light conditions, where they outperform their silicon counterparts. Nanomaterials are at the very heart of DSSC, as the success of its design is due to the use of nanostructures at both the anode and the cathode. In this review, we present the state of the art for both n-type and p-type semiconductors used in the photoelectrodes of DSSCs, showing the evolution of the materials during the 25 years of history of this kind of devices. In the case of p-type semiconductors, also some other energy conversion applications are touched upon.

  9. Doped Heterojunction Used in Quantum Dot Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Yanyan Gao

    2014-01-01

    Full Text Available Incorporated foreign atoms into the quantum dots (QDs used in heterojunction have always been a challenge for solar energy conversion. A foreign atom indium atom was incorporated into PbS/CdS QDs to prepare In-PbS/In-CdS heterojunction by successive ionic layer adsorption and reaction method which is a chemical method. Experimental results indicate that PbS or CdS has been doped with In by SILAR method; the concentration of PbS and CdS which was doped In atoms has no significantly increase or decrease. In addition, incorporating of Indium atoms has resulted in the lattice distortions or changes of PbS or CdS and improved the light harvest of heterojunction. Using this heterojunction, Pt counter electrode and polysulfide electrolyte, to fabricate quantum dot sensitized solar cells, the short circuit current density ballooned to 27.01 mA/cm2 from 13.61 mA/cm2 and the open circuit voltage was improved to 0.43 V from 0.37 V at the same time.

  10. Cell sensitivity to irradiation and DNA repair processes. II

    International Nuclear Information System (INIS)

    Kozubek, S.; Krasavin, E.A.

    1984-01-01

    A new model of DNA single-strand break (SSB) and double-strand break (DSB) induction by radiations of different linear energy transfer (LET) has been developed. Utilizing quadratic dependence of the dose that delta-electrons depart in the track of heavy particles the fraction of heavy particle energy deposited in the target of DNA dimensions has been calculated. SSBs arise from energy depositions in one strand of DNA, direct DSBs arise from two SSBs on opposite strands of DNA in the track of one particle. It is concluded that DSB's induced by γ-radiation are mostly of enzymatic origin, meanwhile DSB's induced by high-LET radiation are direct DSB's. The dependence of radiosensitivity D 0 -1 on LET (L) for isogenic mutants of E. coli with different sensitivity to γ-radiation has been determined on the bases of the model and considering microscopic energy fluctuations. The shape of D 0 -1 (L) function is formed both by physical characteristics of radiation and by the ability of cells to repair some types of DNA damage. The model provides a basis for further investigation. (author)

  11. Tuning pentacene based dye-sensitized solar cells.

    Science.gov (United States)

    Kunzmann, Andreas; Gruber, Marco; Casillas, Rubén; Tykwinski, Rik R; Costa, Rubén D; Guldi, Dirk M

    2018-05-10

    We report on the synthesis, as well as photophysical and electrochemical characterization of a new family of pentacene derivatives, which are applied in n-type dye-sensitized solar cells (DSSCs). As far as the molecular structure of the pentacene is concerned, the synthetic design focuses on cyano acrylic tethered at the 13-position of the pentacene chromophore. The electrolyte composition features increasing amounts of Li+ ions as an additive. In general, the increase of Li+ concentrations extrinsically reduces the quasi Fermi level of the photoanode and as such facilitates the electron injection process. We demonstrate that pentacene derivatives give rise to a unique charge injection process, which is controlled by the positioning of the quasi Fermi level energies as a function of the Li+ concentration. As a result of the enhanced charge injection, device efficiencies as high as 1.5% are achieved, representing a 3-fold increase from previously reported efficiencies in pentacene-based DSSCs. These findings are supported by device analysis in combination with transient absorption and electrochemical impedance spectroscopy assays.

  12. Glioblastoma Cell Malignancy and Drug Sensitivity Are Affected by the Cell of Origin

    Directory of Open Access Journals (Sweden)

    Yiwen Jiang

    2017-01-01

    Full Text Available The identity of the glioblastoma (GBM cell of origin and its contributions to disease progression and treatment response remain largely unknown. We have analyzed how the phenotypic state of the initially transformed cell affects mouse GBM development and essential GBM cell (GC properties. We find that GBM induced in neural stem-cell-like glial fibrillary acidic protein (GFAP-expressing cells in the subventricular zone of adult mice shows accelerated tumor development and produces more malignant GCs (mGC1GFAP that are less resistant to cancer drugs, compared with those originating from more differentiated nestin- (mGC2NES or 2,′3′-cyclic nucleotide 3′-phosphodiesterase (mGC3CNP-expressing cells. Transcriptome analysis of mouse GCs identified a 196 mouse cell origin (MCO gene signature that was used to partition 61 patient-derived GC lines. Human GC lines that clustered with the mGC1GFAP cells were also significantly more self-renewing, tumorigenic, and sensitive to cancer drugs compared with those that clustered with mouse GCs of more differentiated origin.

  13. In vivo assay of the radiation sensitivity of hypoxic tumour cells. Influence of radiation quality and hypoxic sensitization

    International Nuclear Information System (INIS)

    Porschen, W.; Bosiljanoff, P.; Gewehr, K.; Muehlensiepen, H.; Feinendegen, L.E.

    1977-01-01

    In order to measure quantitatively tumour cell kinetics in living mice, tumour bearing animals (sarcoma-180) received intravenously 5-iodo-2'-deoxyuridine (IUdR), a thymidine analogue, which was labelled with 125 I or with 131 I, both of which can be easily externally counted by their gamma emission. IUdR is stably bound to DNA, reutilization is minimal and the measured activity loss from the tumour later than 50 hours after injection signals cell loss or cell death. The effect of irradiation on euoxic and average tumour cells was studied by sequentially labelling the tumour bearing animals first with 125 IUdR and, 70 hours later, with 131 IUdR. At the time of the second injection the average tumour cell population is labelled by the first injection of 125 IUdR, and the second injection of 131 IUdR nearly exclusively tags the perivascular tumour cells; these are euoxic in contrast to the average tumour cell, a large proportion of which is hypoxic. The radiation-induced activity loss rates from the two labelled tumour cell populations indicate the sensitivities of the two populations. At dose levels that cause identical effects on euoxic cells, the ratio of radiation-induced enhancement of cell loss rates for euoxic cells to average cells was 2.6 for 60 Co gamma radiation, 1.4 for 15MeV neutron irradiation, and 1.0 for alpha irradiation (1.5.MeV). The effect of five hypoxic cell sensitizers was analysed. The sensitization was limited to hypoxic cells, and the most effective drug was Ro-07-0582, showing at the 50% level of maximum effect a dose modifying factor of 1.5. Sensitization was highest when the drug was given 15 min prior to irradiation. Hyperthermia affected nearly exclusively hypoxic cells and showed a dose modifying factor of about 2 when the tumours were heated at 42 0 C for 30 min immediately after irradiation. The resulting enhancement of effect was reduced when hyperthermia was applied prior to irradiation. (author)

  14. Deep sea minerals prolong life span of streptozotocin-induced diabetic rats by compensatory augmentation of the IGF-I-survival signaling and inhibition of apoptosis.

    Science.gov (United States)

    Liao, Hung-En; Shibu, Marthandam Asokan; Kuo, Wei-Wen; Pai, Pei-Ying; Ho, Tsung-Jung; Kuo, Chia-Hua; Lin, Jing-Ying; Wen, Su-Ying; Viswanadha, Vijaya Padma; Huang, Chih-Yang

    2016-07-01

    Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia-induced cardiac-apoptosis that causes severe cardiac-damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio-protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg(-1) ) IP injection. Different doses of DSM-1× (37 mg kg(-1) day(-1) ), 2× (74 mg kg(-1) day(-1) ) and 3× (111 mg kg(-1) day(-1) ), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4 . Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac-apoptosis and control cardiac-dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac-cell proliferation and by controlling cardiac-apoptosis and associated cardiac-dysfunction. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 769-781, 2016. © 2015 Wiley Periodicals, Inc.

  15. Polymorphisms of genes coding for ghrelin and its receptor in relation to anthropometry, circulating levels of IGF-I and IGFBP-3, and breast cancer risk: a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC).

    Science.gov (United States)

    Dossus, Laure; McKay, James D; Canzian, Federico; Wilkening, Stefan; Rinaldi, Sabina; Biessy, Carine; Olsen, Anja; Tjønneland, Anne; Jakobsen, Marianne U; Overvad, Kim; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Fournier, Agnes; Linseisen, Jakob; Lukanova, Annekatrin; Boeing, Heiner; Fisher, Eva; Trichopoulou, Antonia; Georgila, Christina; Trichopoulos, Dimitrios; Palli, Domenico; Krogh, Vittorio; Tumino, Rosario; Vineis, Paolo; Quirós, José Ramon; Sala, Núria; Martínez-García, Carmen; Dorronsoro, Miren; Chirlaque, Maria-Dolores; Barricarte, Aurelio; van Duijnhoven, Fränzel J B; Bueno-de-Mesquita, H B; van Gils, Carla H; Peeters, Petra H M; Hallmans, Göran; Lenner, Per; Bingham, Sheila; Khaw, Kay Tee; Key, Tim J; Travis, Ruth C; Ferrari, Pietro; Jenab, Mazda; Riboli, Elio; Kaaks, Rudolf

    2008-07-01

    Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, has two major functions: the stimulation of the growth hormone production and the stimulation of food intake. Accumulating evidence also suggests a role of ghrelin in cancer development. We conducted a case-control study on 1359 breast cancer cases and 2389 matched controls, nested within the European Prospective Investigation into Cancer and Nutrition, to examine the association of common genetic variants in the genes coding for ghrelin (GHRL) and its receptor (GHSR) with anthropometric measures, circulating insulin growth factor I (IGF-I) and insulin-like growth factor-binding protein 3 and breast cancer risk. Pair-wise tagging was used to select the 15 polymorphisms that represent the majority of common genetic variants across the GHRL and GHSR genes. A significant increase in breast cancer risk was observed in carriers of the GHRL rs171407-G allele (odds ratio: 1.2; 95% confidence interval: 1.0-1.4; P = 0.02). The GHRL single-nucleotide polymorphism rs375577 was associated with a 5% increase in IGF-I levels (P = 0.01). A number of GHRL and GHSR polymorphisms were associated with body mass index (BMI) and height (P between GHRL variations are associated with BMI. Furthermore, we have observed evidence for association of GHRL polymorphisms with circulating IGF-I levels and with breast cancer risk. These associations, however, might also be due to chance findings and further large studies are needed to confirm our results.

  16. Characterization of mitomycin-C-sensitive mouse lymphoma L5178Y cell mutants

    International Nuclear Information System (INIS)

    Inaba, Hiroko; Shiomi, Naoko; Shiomi, Tadahiro; Sato, Koki; Yoshida, Michihiro.

    1985-01-01

    Twenty-six mutants showing high sensitivity to mytomicin-C (MMC) were isolated from mouse lymphoma L5178Y cells by a replica-plating technique. Twenty-five of the mutants were 5 - 10 times more sensitive to MMC than were parental cells, and showed normal sensitivity to U.V. light and x-rays. From a complementation analysis, 5 mutants (MC s ) isolated from independently mutagenized cell populations were classified into two groups. These mutants possessed recessive character for MMC-sensitivity and there were at least two genes involved in the MMC-sensitivity. As for DNA-damaging factors, such as photoadducts of 8-methoxypsoralen (8-MOP) and 3-carbethoxysoralen (3-CPs), MC s mutants showed higher sensitivity to photoadducts of 8-MOP than to (3-CPs). MC s mutants were also highly sensitive to a DNA cross-linking agent, cisplatin. Characterization of the sensitivity of mouse MC s mutants was analogous to that of Fanconi's anemia (FA)-derived cells. Low concentrations (10 ng/ml) of MMC induced chromosome aberration in a high incidence in mouse MC s cells, as well as in FA cells. The frequency of MMC-induced chromosome aberrations was normal in hybrid cells between normal human diploid somatic cells and mouse mutants and between FA cells and mouse wild cells, and hereditary deficiency became normal by hybrization. (Namekawa, K.)

  17. Labeling of mesenchymal stem cells for MRI with single-cell sensitivity

    Directory of Open Access Journals (Sweden)

    Ariza de Schellenberger A

    2016-04-01

    Full Text Available Angela Ariza de Schellenberger,1 Harald Kratz,1 Tracy D Farr,2,3 Norbert Löwa,4 Ralf Hauptmann,1 Susanne Wagner,1 Matthias Taupitz,1 Jörg Schnorr,1 Eyk A Schellenberger1 1Department of Radiology, 2Department of Experimental Neurology, Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany; 3School of Life Sciences, University of Nottingham, Medical School, Nottingham, UK; 4Department of Biomagnetic Signals, Physikalisch-Technische Bundesanstalt Berlin, Berlin, Germany Abstract: Sensitive cell detection by magnetic resonance imaging (MRI is an important tool for the development of cell therapies. However, clinically approved contrast agents that allow single-cell detection are currently not available. Therefore, we compared very small iron oxide nanoparticles (VSOP and new multicore carboxymethyl dextran-coated iron oxide nanoparticles (multicore particles, MCP designed by our department for magnetic particle imaging (MPI with discontinued Resovist® regarding their suitability for detection of single mesenchymal stem cells (MSC by MRI. We achieved an average intracellular nanoparticle (NP load of >10 pg Fe per cell without the use of transfection agents. NP loading did not lead to significantly different results in proliferation, colony formation, and multilineage in vitro differentiation assays in comparison to controls. MRI allowed single-cell detection using VSOP, MCP, and Resovist® in conjunction with high-resolution T2*-weighted imaging at 7 T with postprocessing of phase images in agarose cell phantoms and in vivo after delivery of 2,000 NP-labeled MSC into mouse brains via the left carotid artery. With optimized labeling conditions, a detection rate of ~45% was achieved; however, the experiments were limited by nonhomogeneous NP loading of the MSC population. Attempts should be made to achieve better cell separation for homogeneous NP loading and to thus improve NP

  18. IDH1-mutant cancer cells are sensitive to cisplatin and an IDH1-mutant inhibitor counteracts this sensitivity.

    Science.gov (United States)

    Khurshed, Mohammed; Aarnoudse, Niels; Hulsbos, Renske; Hira, Vashendriya V V; van Laarhoven, Hanneke W M; Wilmink, Johanna W; Molenaar, Remco J; van Noorden, Cornelis J F

    2018-06-07

    Isocitrate dehydrogenase ( IDH1)-1 is mutated in various types of human cancer, and the presence of this mutation is associated with improved responses to irradiation and chemotherapy in solid tumor cells. Mutated IDH1 (IDH1 MUT ) enzymes consume NADPH to produce d-2-hydroxyglutarate (d-2HG) resulting in the decreased reducing power needed for detoxification of reactive oxygen species (ROS), for example. The objective of the current study was to investigate the mechanism behind the chemosensitivity of the widely-used anticancer agent cisplatin in IDH1 MUT cancer cells. Oxidative stress, DNA damage, and mitochondrial dysfunction caused by cisplatin treatment were monitored in IDH1 MUT HCT116 colorectal cancer cells and U251 glioma cells. We found that exposure to cisplatin induced higher levels of ROS, DNA double-strand breaks (DSBs), and cell death in IDH1 MUT cancer cells, as compared with IDH1 wild-type ( IDH1 WT ) cells. Mechanistic investigations revealed that cisplatin treatment dose dependently reduced oxidative respiration in IDH1 MUT cells, which was accompanied by disturbed mitochondrial proteostasis, indicative of impaired mitochondrial activity. These effects were abolished by the IDH1 MUT inhibitor AGI-5198 and were restored by treatment with d-2HG. Thus, our study shows that altered oxidative stress responses and a vulnerable oxidative metabolism underlie the sensitivity of IDH1 MUT cancer cells to cisplatin.-Khurshed, M., Aarnoudse, N., Hulsbos, R., Hira, V. V. V., van Laarhoven, H. W. M., Wilmink, J. W., Molenaar, R. J., van Noorden, C. J. F. IDH1-mutated cancer cells are sensitive to cisplatin and an IDH1-mutant inhibitor counteracts this sensitivity.

  19. Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

    Science.gov (United States)

    Hossain, Md. Khalid; Pervez, M. Firoz; Mia, M. N. H.; Mortuza, A. A.; Rahaman, M. S.; Karim, M. R.; Islam, Jahid M. M.; Ahmed, Farid; Khan, Mubarak A.

    In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric) sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV-Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell's (DSSC) photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric.

  20. A strategy of combining SILAR with solvothermal process for In2S3 sensitized quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Yang, Peizhi; Tang, Qunwei; Ji, Chenming; Wang, Haobo

    2015-01-01

    Graphical abstract: - Highlights: • In 2 S 3 sensitized TiO 2 anode is prepared by combining SILAR with solvothermal process. • The deposition cycle in SILAR process has an impact on cell performances. • A promising conversion efficiency of 1.39% is obtained for the optimal device. • The cell performances are markedly increased compared with SILAR technique. - Abstract: Pursuit of an efficient strategy for quantum dot-sensitized photoanode has been a persistent objective for enhancing photovoltaic performances of quantum dot-sensitized solar cell (QDSC). We present here the fabrication of the indium sulfide (In 2 S 3 ) quantum dot-sensitized titanium dioxide (TiO 2 ) photoanode by combining successive ionic layer adsorption and reaction (SILAR) with solvothermal processes. The resultant QDSC consists of an In 2 S 3 sensitized TiO 2 photoanode, a liquid polysulfide electrolyte, and a Co 0.85 Se counter electrode. The optimized QDSC with photoanode prepared with the help of a SILAR method at 20 deposition cycles and solvothermal method yields a maximum power conversion efficiency of 1.39%.

  1. Sensitization of gastric cancer cells to alkylating agents by glaucocalyxin B via cell cycle arrest and enhanced cell death.

    Science.gov (United States)

    Ur Rahman, Muhammad Saif; Zhang, Ling; Wu, Lingyan; Xie, Yuqiong; Li, Chunchun; Cao, Jiang

    2017-01-01

    Severe side effects are major problems with chemotherapy of gastric cancer (GC). These side effects can be reduced by using sensitizing agents in combination with therapeutic drugs. In this study, the low/nontoxic dosage of glaucocalyxin B (GLB) was used with other DNA linker agents mitomycin C (MMC), cisplatin (DDP), or cyclophosphamide (CTX) to treat GC cells. Combined effectiveness of GLB with drugs was determined by proliferation assay. The molecular mechanisms associated with cell proliferation, migration, invasion, cell cycle, DNA repair/replication, apoptosis, and autophagy were investigated by immunoblotting for key proteins involved. Cell cycle and apoptosis analysis were performed by flow cytometry. Reactive oxygen species level was also examined for identification of its role in apoptosis. Proliferation assay revealed that the addition of 5 µM GLB significantly sensitizes gastric cancer SGC-7901 cells to MMC, DDP, and CTX by decreasing half-maximal inhibitory concentration (IC 50 ) by up to 75.40%±5%, 45.10%±5%, and 52.10%±5%, respectively. GLB + drugs decreased the expression level of proteins involved in proliferation and migration, suggesting the anticancer potential of GLB + drugs. GLB + MMC, GLB + CTX, and GLB + DDP arrest the cells in G 0 /G 1 and G 1 /S phase, respectively, which may be the consequence of significant decrease in the level of enzymes responsible for DNA replication and telomerase shortening. Combined use of GLB with these drugs also induces DNA damage and apoptosis by activating caspase/PARP pathways and increased production of reactive oxygen species and increased autophagy in GC cells. GLB dosage sensitizes GC cells to the alkylating agents via arresting the cell cycle and enhancing cell death. This is of significant therapeutic importance in the reduction of side effects associated with these drugs.

  2. Effect of 17-AAG on radio-sensitivity of HeLa and V79 cells

    International Nuclear Information System (INIS)

    Pan Yanling; Hong Chengjiao; Zhang Baoguo

    2010-01-01

    In order to investigate the radio-sensitizing effect of 17-AAG, an inhibitor of Heat Shock Protein 90, on human Uterine Cervix Cancer HeLa and V79 cells, Clonogenic assay was used to observe the cell survival rate. The results show that 17-AAG can decrease obviously (p 0.05). This indicates that 17-AAG may enhance the radio-sensitivity of the HeLa cell line and has no effect on the V79 cell line. (authors)

  3. Increased cardiac alpha-myosin heavy chain in left atria and decreased myocardial insulin-like growth factor (Igf-I) expression accompany low heart rate in hibernating grizzly bears.

    Science.gov (United States)

    Barrows, N D; Nelson, O L; Robbins, C T; Rourke, B C

    2011-01-01

    Grizzly bears (Ursus arctos horribilis) tolerate extended periods of extremely low heart rate during hibernation without developing congestive heart failure or cardiac chamber dilation. Left ventricular atrophy and decreased left ventricular compliance have been reported in this species during hibernation. We evaluated the myocardial response to significantly reduced heart rate during hibernation by measuring relative myosin heavy-chain (MyHC) isoform expression and expression of a set of genes important to muscle plasticity and mass regulation in the left atria and left ventricles of active and hibernating bears. We supplemented these data with measurements of systolic and diastolic function via echocardiography in unanesthetized grizzly bears. Atrial strain imaging revealed decreased atrial contractility, decreased expansion/reservoir function (increased atrial stiffness), and decreased passive-filling function (increased ventricular stiffness) in hibernating bears. Relative MyHC-α protein expression increased significantly in the atrium during hibernation. The left ventricle expressed 100% MyHC-β protein in both groups. Insulin-like growth factor (IGF-I) mRNA expression was reduced by ∼50% in both chambers during hibernation, consistent with the ventricular atrophy observed in these bears. Interestingly, mRNA expression of the atrophy-related ubiquitin ligases Muscle Atrophy F-box (MAFBx) and Muscle Ring Finger 1 did not increase, nor did expression of myostatin or hypoxia-inducible factor 1α (HIF-1α). We report atrium-specific decreases of 40% and 50%, respectively, in MAFBx and creatine kinase mRNA expression during hibernation. Decreased creatine kinase expression is consistent with lowered energy requirements and could relate to reduced atrial emptying function during hibernation. Taken together with our hemodynamic assessment, these data suggest a potential downregulation of atrial chamber function during hibernation to prevent fatigue and dilation

  4. Sensitization of B-cell chronic lymphocytic leukemia cells to recombinant immunotoxin by immunostimulatory phosphorothioate oligodeoxynucleotides.

    Science.gov (United States)

    Decker, Thomas; Hipp, Susanne; Kreitman, Robert J; Pastan, Ira; Peschel, Christian; Licht, Thomas

    2002-02-15

    A recombinant anti-CD25 immunotoxin, LMB-2, has shown clinical efficacy in hairy cell leukemia and T-cell neoplasms. Its activity in B-cell chronic lymphocytic leukemia (B-CLL) is inferior but might be improved if B-CLL cells expressed higher numbers of CD25 binding sites. It was recently reported that DSP30, a phosphorothioate CpG-oligodeoxynucleotide (CpG-ODN) induces immunogenicity of B-CLL cells by up-regulation of CD25 and other antigens. The present study investigated the antitumor activity of LMB-2 in the presence of DSP30. To this end, B-CLL cells from peripheral blood of patients were isolated immunomagnetically to more than 98% purity. Incubation with DSP30 for 48 hours augmented CD25 expression in 14 of 15 B-CLL samples, as assessed by flow cytometry. DSP30 increased LMB-2 cytotoxicity dose dependently whereas a control ODN with no CpG motif did not. LMB-2 displayed no antitumor cell activity in the absence of CpG-ODN as determined colorimetrically with an (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. In contrast, B-CLL growth was inhibited in 12 of 13 samples with 50% inhibition concentrations (IC(50)) in the range of LMB-2 plasma levels achieved in clinical studies. Two samples were not evaluable because of spontaneous B-CLL cell death in the presence of DSP30. Control experiments with an immunotoxin that does not recognize hematopoietic cells, and an anti-CD22 immunotoxin, confirmed that sensitization to LMB-2 was specifically due to up-regulation of CD25. LMB-2 was much less toxic to normal B and T lymphocytes compared with B-CLL cells. In summary, immunostimulatory CpG-ODNs efficiently sensitize B-CLL cells to a recombinant immunotoxin by modulation of its target. This new treatment strategy deserves further attention.

  5. Synthesis of dye-sensitized solar cells. Efficiency cells as a thickness of titanium dioxide

    Directory of Open Access Journals (Sweden)

    Szura Dominika

    2017-01-01

    Full Text Available Defying the influence of the thickness of TiO2 efficiency of dye-sensitized solar cell. It was confirmed that the compatibility of printed layers with the parameters closely related with the DSSC. It was found that the increase in thickness of the titanium dioxide layer, increases the distance between the electrodes, determined by the thickness of the Surlyn foil. With the rise of thickness of dyed layer of TiO2 established decrease in the value of its transmittance. Greatest transparency and aesthetic value obtained for photovoltaic modules with a single layer of titanium dioxide. The improved performance efficiency and preferred yields maximum power were noticed and exhibited by the cells covered with three layers of TiO2. It was established that the behaviour of economic efficiency in the production process, provides a range of cells with two layers of oxide, showing a similar performance and greater transparency.

  6. A strategy of combining SILAR with solvothermal process for In2S3 sensitized quantum dot-sensitized solar cells

    Science.gov (United States)

    Yang, Peizhi; Tang, Qunwei; Ji, Chenming; Wang, Haobo

    2015-12-01

    Pursuit of an efficient strategy for quantum dot-sensitized photoanode has been a persistent objective for enhancing photovoltaic performances of quantum dot-sensitized solar cell (QDSC). We present here the fabrication of the indium sulfide (In2S3) quantum dot-sensitized titanium dioxide (TiO2) photoanode by combining successive ionic layer adsorption and reaction (SILAR) with solvothermal processes. The resultant QDSC consists of an In2S3 sensitized TiO2 photoanode, a liquid polysulfide electrolyte, and a Co0.85Se counter electrode. The optimized QDSC with photoanode prepared with the help of a SILAR method at 20 deposition cycles and solvothermal method yields a maximum power conversion efficiency of 1.39%.

  7. Resveratrol Sensitizes Selectively Thyroid Cancer Cell to 131-Iodine Toxicity

    Directory of Open Access Journals (Sweden)

    Seyed Jalal Hosseinimehr

    2014-01-01

    Full Text Available Background. In this study, the radiosensitizing effect of resveratrol as a natural product was investigated on cell toxicity induced by 131I in thyroid cancer cell. Methods. Human thyroid cancer cell and human nonmalignant fibroblast cell (HFFF2 were treated with 131I and/or resveratrol at different concentrations for 48 h. The cell proliferation was measured by determination of the percent of the survival cells using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results. Findings of this study show that resveratrol enhanced the cell death induced by 131I on thyroid cancer cell. Also, resveratrol exhibited a protective effect on normal cells against 131I toxicity. Conclusion. This result indicates a promising effect of resveratrol on improvement of cellular toxicity during iodine therapy.

  8. RasGRP1 confers the phorbol ester-sensitive phenotype to EL4 lymphoma cells.

    Science.gov (United States)

    Han, Shujie; Knoepp, Stewart M; Hallman, Mark A; Meier, Kathryn E

    2007-01-01

    The murine EL4 lymphoma cell line exists in variants that are either sensitive or resistant to the tumor promoter phorbol 12-myristate 13-acetate (PMA). In sensitive EL4 cells, PMA causes robust Erk mitogen-activated protein kinase activation that results in growth arrest. In resistant cells, PMA induces minimal Erk activation, without growth arrest. PMA stimulates IL-2 production in sensitive, but not resistant, cells. The role of RasGRP1, a PMA-activated guanine nucleotide exchange factor for Ras, in EL4 phenotype was examined. Endogenous RasGRP1 protein is expressed at much higher levels in sensitive than in resistant cells. PMA-induced Ras activation is observed in sensitive cells but not in resistant cells lacking Ras-GRP1. PMA induces down-regulation of RasGRP1 protein in sensitive cells but increases RasGRP1 in resistant cells. Transfection of RasGRP1 into resistant cells enhances PMA-induced Erk activation. In the reverse experiment, introduction of small interfering RNA (siRNA) for RasGRP1 suppresses PMA-induced Ras and Erk activations in sensitive cells. Sensitive cells incubated with siRNA for RasGRP1 exhibit the PMA-resistant phenotype, in that they are able to proliferate in the presence of PMA and do not secrete IL-2 when stimulated with PMA. These studies indicate that the PMA-sensitive phenotype, as previously defined for the EL4 cell line, is conferred by endogenous expression of RasGRP1 protein.

  9. The attractive Achilles heel of germ cell tumours : an inherent sensitivity to apoptosis-inducing stimuli

    NARCIS (Netherlands)

    Spierings, DCJ; de Vries, EGE; Vellenga, E; de Jong, S

    Testicular germ cell tumours (TGCTs) are extremely sensitive to cisplatin-containing chemotherapy. The rapid time course of apoptosis induction after exposure to cisplatin suggests that TGCT cells are primed to undergo programmed cell death as an inherent property of the cell of origin. In fact,

  10. Thermal radiosensitization in heat- and radiation-sensitive mutants of CHO cells

    International Nuclear Information System (INIS)

    Kampinga, H.H.; Kanon, B.; Konings, A.W.T.; Stackhouse, M.A.; Bedford, J.S.

    1993-01-01

    In the current study, the extent of hyperthermic radiosensitization in a new γ-radiation-sensitive cell line, irs-20, recently isolated by Stackhouse and Bedford (1991) and a heat-sensitive mutant hs-36 (Harvey and Bedford 1988) was compared with the radiosensitization of their mutual parent CHO 10B12 cell line. The irs-20 and CHO 10B12 cells have comparable heat (43.5 o C) sensitivities, whereas hs-36 and CHO 10B12 show a similar sensitivity to γ- and X-rays. Radiosensitization due to pre-exposure to 43.5 o C heating of plateau phase cultures was found for all three cell lines, even after relatively mild heat treatment killing <20% of cells. Experiments using CHEF electrophoresis confirmed the dsb repair deficiency of the irs-20 cells (Stackhouse and Bedford 1992) and showed that heat inhibited dsb repair in all three cell lines. (Author)

  11. Tumor necrosis factor alpha selectively sensitizes human immunodeficiency virus-infected cells to heat and radiation

    International Nuclear Information System (INIS)

    Wong, G.H.; McHugh, T.; Weber, R.; Goeddel, D.V.

    1991-01-01

    We report here that infection of the human T-cell line HUT-78 with human immunodeficiency virus (HIV) increases its sensitivity to heat and radiation toxicity. A possible explanation for this result may be the reduced expression of manganous superoxide dismutase (MnSOD) in HIV-infected cells compared to uninfected cells. Tumor necrosis factor alpha (TNF-alpha) further sensitizes HIV-infected cells but not uninfected cells to heat and radiation. This is consistent with the ability of TNF-alpha to induce the expression of MnSOD in uninfected but not in HIV-infected cells. HIV-infected HUT-78 cell lines engineered to overexpress MnSOD are more resistant to heat and radiation than HIV-infected cells that do not overexpress MnSOD. However, treatment with TNF-alpha still sensitizes these cells to heat and radiation

  12. Relationship between laminin binding capacity and laminin expression on tumor cells sensitive or resistant to natural cell-mediated cytotoxicity

    International Nuclear Information System (INIS)

    Laybourn, K.A.; Varani, J.; Fligiel, S.E.G.; Hiserodt, J.C.

    1986-01-01

    Previous studies have identified the presence of laminin binding sites on murine NK and NC sensitive tumor cells by 125 I-laminin binding and laminin induced cell-cell aggregation. The finding that the addition of exogenous laminin inhibits NK/NC binding to sensitive tumor cells suggests laminin binding sites may serve as target antigens for NK cells. The present study extends earlier reports by analyzing a large panel of tumor cells for laminin binding capacity, laminin expression and sensitivity to NK/NC killing. The data indicate that all tumor cells which bind to NK/NC cells (8 lines tested) express laminin binding sites. All of these tumor cells were capable of competing for NK lysis of YAC-1 cells in cold target competition assays, and all bound enriched NK cells in direct single cell binding assays. In contrast, tumor cells expressing high levels of surface laminin (B16 melanomas, C57B1/6 fibrosarcomas, and RAS transfected 3T3 fibroblasts) but low levels of laminin binding capacity did not bind NK/NC cells and were resistant to lysis. These data support the hypothesis that expression of laminin/laminin binding sites may contribute to tumor cell sensitivity to NK/NC binding and/or killing

  13. Mechanism of hyperthermic potentiation of cisplatin action in cisplatin-sensitive and -resistant tumour cells

    NARCIS (Netherlands)

    Hettinga, JVE; Lemstra, W; Meijer, C; Dam, WA; Uges, DRA; Konings, AWT; DeVries, EGE; Kampinga, HH

    1997-01-01

    In this study, the mechanism(s) by which heat increases cis-diamminedichloroplatinum (cisplatin, cDDP) sensitivity in cDDP-sensitive and -resistant cell lines of murine as well as human origin were investigated. Heating cells at 43 degrees C during cDDP exposure was found to increase drug

  14. Enhancement of Bleomycin Sensitivity in Human Lung Cancer Cell ...

    African Journals Online (AJOL)

    Methods: The inhibitory effect of bleomycin on A549 cells was determined by incubating the cells for 24 h in different .... also include advantageous psychological effects such as .... cyclooxygenase-2 enzyme inhibitors: A rational advance?

  15. Cell membrane temperature rate sensitivity predicted from the Nernst equation.

    Science.gov (United States)

    Barnes, F S

    1984-01-01

    A hyperpolarized current is predicted from the Nernst equation for conditions of positive temperature derivatives with respect to time. This ion current, coupled with changes in membrane channel conductivities, is expected to contribute to a transient potential shift across the cell membrane for silent cells and to a change in firing rate for pacemaker cells.

  16. Mifepristone sensitizing cisplatin for cervical adenocarcinoma HeLa cell sensitivity to chemotherapy and its mechanism.

    Science.gov (United States)

    Li, Caihong; Ye, Hong

    2013-01-01

    The study was designed to investigate proliferation inhibition for cervical adenocarcinoma HeLa cell treated with cisplatin combined with mifepristone and access its possible mechanism. HeLa cell was processed by different concentrations of mifepristone, cisplatin, and their combination respectively. Cell's proliferation inhibition rate and induction apoptosis ability were detected by MTT assay, FCM; the expression of P53, survivin and HPV E6 protein were measured by Western Blot. The results showed that cisplatin inhibits proliferation of HeLa cells in different concentrations (p 0.05). Mifepristone at low concentrations (cisplatin can significantly enhance the inhibitory effect of cisplatin on HeLa cell line. Flow cytometry showed that mifepristone at low concentrations (cisplatin can induce apparent apoptosis of HeLa cell line in concentration dependent manner. Western blotting demonstrated that the expression of P53 protein increased and the expression of HPV E6 survivin protein decreased in HeLa cells treated with MIF at low concentrations (cisplatin. Mifepristone at low concentrations (cisplatin to HeLa cells. The strengthening effect of growth inhibition and chemosensitivity to cisplatin of mifepristone are associated with down-regulating HPV E6 survivin protein and upregulating p53 protein.

  17. Synthesis of CdSe quantum dots for quantum dot sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Neetu, E-mail: singh.neetu1985@gmail.com; Kapoor, Avinashi [Department of Electronic Science, University of Delhi South Campus, New Delhi-110 021 (India); Kumar, Vinod [Department of Physics, University of the Free State, Bloemfontein, ZA9300 (South Africa); Mehra, R. M. [School of Engineering and Technology, Sharda University, Greater Noida-201 306, U.P. (India)

    2014-04-24

    CdSe Quantum Dots (QDs) of size 0.85 nm were synthesized using chemical route. ZnO based Quantum Dot Sensitized Solar Cell (QDSSC) was fabricated using CdSe QDs as sensitizer. The Pre-synthesized QDs were found to be successfully adsorbed on front ZnO electrode and had potential to replace organic dyes in Dye Sensitized Solar Cells (DSSCs). The efficiency of QDSSC was obtained to be 2.06 % at AM 1.5.

  18. Synthesis and characterization of novel heteroleptic ruthenium sensitizer for nanocrystalline dye-sensitized solar cells

    NARCIS (Netherlands)

    Sivakumar, R.; Marcelis, A.T.M.; Anandan, S.

    2009-01-01

    A novel heteroleptic ruthenium complex of the type [Ru(bpin)(dcbpyH2)Cl]Cl (where bpin is 2,6-bis(pyrazol-1-yl)isonicotinic acid and dcbpyH2 is 4,4'-dicarboxy-2,2'-bipyridine) was synthesized and characterized for tuning the LUMO level of the ruthenium sensitizer to achieve greater stabilization in

  19. Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Md. Khalid Hossain

    Full Text Available In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV–Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell’s (DSSC photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric. Keywords: DSSC, Natural dye, TiO2 photoanode, Dye extracting solvent, Dye-adsorption time

  20. In vitro sensitization of human lymphocytes to a myeloma cell-related antigen

    International Nuclear Information System (INIS)

    Whitson, M.E.; Griffin, G.D.; Novelli, G.D.; Solomon, A.

    1981-01-01

    Peripheral blood lymphocytes from normal human donors were cocultivated with cells from two established human multiple myeloma cell lines, RPMI 8226 and K-737, and with lymphoblastoid cells from a third B cell line, RAMM. After a comparison of three methods of lymphocyte sensitization, a 6-day incubation protocol with equal numbers of normal lymphocytes and mitomycin C-treated tumor cells was selected. Cells fom the RPMI 8226 myeloma line stimulated the differentiation of lymphocytes into cytotoxic effector cells as measured by 51 Cr release from labeled target cells. The RPMI 8226-sensitized lymphocytes were cytotoxic for myeloma cells (RPMI 8226 and K-737) and for lymphoblastoid cells (RAMM) but not for cells from human lung tumor lines (A549, A427, MB9812), a breast carcinoma line (ALAB), a normal diploid fibroblast line (HSBP), or normal lymphocytes

  1. In vitro sensitization of human lymphocytes to a myeloma cell-related antigen

    Energy Technology Data Exchange (ETDEWEB)

    Whitson, M.E. (Univ. of South Carolina, Columbia); Griffin, G.D.; Novelli, G.D.; Solomon, A.

    1981-01-01

    Peripheral blood lymphocytes from normal human donors were cocultivated with cells from two established human multiple myeloma cell lines, RPMI 8226 and K-737, and with lymphoblastoid cells from a third B cell line, RAMM. After a comparison of three methods of lymphocyte sensitization, a 6-day incubation protocol with equal numbers of normal lymphocytes and mitomycin C-treated tumor cells was selected. Cells fom the RPMI 8226 myeloma line stimulated the differentiation of lymphocytes into cytotoxic effector cells as measured by /sup 51/Cr release from labeled target cells. The RPMI 8226-sensitized lymphocytes were cytotoxic for myeloma cells (RPMI 8226 and K-737) and for lymphoblastoid cells (RAMM) but not for cells from human lung tumor lines (A549, A427, MB9812), a breast carcinoma line (ALAB), a normal diploid fibroblast line (HSBP), or normal lymphocytes.

  2. Methylation of the ATM promoter in glioma cells alters ionizing radiation sensitivity

    International Nuclear Information System (INIS)

    Roy, Kanaklata; Wang, Lilin; Makrigiorgos, G. Mike; Price, Brendan D.

    2006-01-01

    Glioblastomas are among the malignancies most resistant to radiation therapy. In contrast, cells lacking the ATM protein are highly sensitive to ionizing radiation. The relationship between ATM protein expression and radiosensitivity in 3 glioma cell lines was examined. T98G cells exhibited normal levels of ATM protein, whereas U118 and U87 cells had significantly lower levels of ATM and increased (>2-fold) sensitivity to ionizing radiation compared to T98G cells. The ATM promoter was methylated in U87 cells. Demethylation by azacytidine treatment increased ATM protein levels in the U87 cells and decreased their radiosensitivity. In contrast, the ATM promoter in U118 cells was not methylated. Further, expression of exogenous ATM did not significantly alter the radiosensitivity of U118 cells. ATM expression is therefore heterogeneous in the glioma cells examined. In conclusion, methylation of the ATM promoter may account for the variable radiosensitivity and heterogeneous ATM expression in a fraction of glioma cells

  3. Applications of chitosan-based thermo-sensitive copolymers for harvesting living cell sheet

    International Nuclear Information System (INIS)

    Chen, J.-P.; Yang, T.-F.

    2008-01-01

    A thermo-sensitive chitosan-based copolymer hydrogel was used for harvesting living cell sheets. The hydrogel was tested for harvesting 3T3 cells after carrying out cell culture at 37 deg. C and incubating the confluent cells at 20 deg. C for spontaneous detachment of cell sheets from hydrogel surface without enzyme treatment. Results from cell viability assay and microscopy observations demonstrated that cells could attach to the hydrogel surface and maintain high viability and proliferation ability. Cell detachment efficiency from the hydrogel was about 80%. The detached cell sheet retained high viability and could proliferate again after transferred to a new culture surface

  4. Krüppel-Like Factor 4 Enhances Sensitivity of Cisplatin to Esophageal Squamous Cell Carcinoma (ESCC) Cells.

    Science.gov (United States)

    Chen, Chuangui; Ma, Zhao; Zhang, Hongdian; Liu, Xiaoqiong; Yu, Zhentao

    2017-07-11

    BACKGROUND The aim of this study was to elucidate the role of Krüppel-Like factor 4 (KLF4) in cisplatin resistance in esophageal squamous cell carcinoma (ESCC) cells, which may eventually help to improve the treatment efficacy. MATERIAL AND METHODS Human esophageal squamous cell carcinoma (ESCC) cell line CaEs-17, TE-1, EC109, KYSE510, KYSE140, KYSE70, and KYSE30 were selected to detect their sensitivity to cisplatin. 5-Azacytidine-2'-deoxycytidine (5'-Aza-CdR) treatment and methylation-specific PCR (MS-PCR) were used to detect the methylation status for KLF4. Cell viability, apoptosis, and cell cycle were measured using methyl thiazolyl tetrazolium (MTT) assay, Annexin V affinity assay, and flow cytometry, respectively. RESULTS The sensitivity to cisplatin was different in the seven ESCC cell lines, with TE-1 having the lowest sensitivity and KYSE140 having the highest sensitivity. Interestingly, the level of KLF4 was relatively low in TE-1 cells; while it was high in KYSE140 cells. These results suggested that KLF4 may be involved in cisplatin resistance. The promoter region was mostly unmethylated in KYSE140 cells; while it was hypermethylated in TE-1 cells. After treatment with demethylation reagent 5-Aza-CdR, cisplatin sensitivities were significantly increased after upregulation of KLF4, as the IC50 values were significantly decreased in the TE-1 cell treated with 5-Aza-CdR. Furthermore, upregulation of KLF4 induced cell apoptosis and cell cycle arrest at S phase. CONCLUSIONS KLF4 enhances the sensitivity of cisplatin to ESCC cells through apoptosis induction and cell cycle arrest. Our data provided a novel insight to the mechanism of cisplatin resistance; overexpression of KLF4 may be a potential therapeutic strategy for cisplatin resistance in human ESCC.

  5. Effect of Quercetin on radio-sensitivity of HeLa cells

    International Nuclear Information System (INIS)

    Wu Xiaofen; Hong Chengjiao; Guo Wenxiu; Pan Yanling; Zhang Baoguo

    2011-01-01

    In order to investigate the mechanism of Quercetin on radio-sensitivity of human Uterine Cervix Cancer HeLa cells, HeLa cells were cultured in different concentrations of Quercetin and different doses of irradiation. The clonogenic assay was used to observe the cell survival rate. The repair of DNA double-strand breaks and effect of Quercetin combination of radiation on the cell cycle were detected by flow cytometry. The results show that the radio-sensitivity of Quercetin on HeLa cells was obvious and the unrepaired DSBs after irradiation increased, but did not decrease G2/M cell cycle arrest. From this it can be inferred that the effect on HeLa cell radio-sensitivity may be related to the inhibition of the repair of DNA double-strand breaks induced by Quercetin, but it dose not reveal a significant relation with the cell cycle and G2/M arrest. (authors)

  6. Distinctions in sensitivity and repair of cells of children with some hereditary diseases

    International Nuclear Information System (INIS)

    Zasukhina, G.D.; Barashnev, Yu.I.; Vasil'eva, I.M.; Sdirkova, N.I.; Semyachkina, A.N.

    1982-01-01

    A study was made of blood cell sensitivity of children, with some hereditary diseases, to ν-radiation and 4-nitro-quinoline-1-oxide. Using the host cell reactivation and chromatographic methods we revealed the increase in the sensitivity to the above mentioned agents and inhibition of the repair function in