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Changes in the NMR Metabolic Profile of Live Human Neuron-Like SH-SY5Y Cells Exposed to Interferon-α2. J Neuroimmune Pharmacol 2015; 11:142-52. [DOI: 10.1007/s11481-015-9641-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/27/2015] [Indexed: 12/29/2022]
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2
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Influence of insulin-like growth factor I on nerve regeneration using allografts: a sciatic nerve model. J Craniofac Surg 2015; 25:1510-4. [PMID: 25006924 DOI: 10.1097/scs.0000000000000783] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Effects of insulin-like growth factor I (IGF I) on peripheral nerve regeneration was studied using allografts in a rat sciatic nerve model. Thirty male white Wistar rats were divided into 3 experimental groups (n = 10) randomly: normal control group (NC), allograft group (ALLO), and IGF I-treated group (ALLO/IGF). In the NC group, the left sciatic nerve was exposed through a gluteal muscle incision and, after homeostasis, the muscle was sutured. In the ALLO group, the left sciatic nerve was exposed through a gluteal muscle incision and transected proximal to the tibioperoneal bifurcation where a 10-mm segment was excised. The same procedure was performed in the ALLO/IGF group. The harvested nerves of the rats of the ALLO group were served as allograft for the ALLO/IGF group and vice versa. The NC and ALLO groups received 10 μL of sterile phosphate buffered saline intraperitoneally once a day for 1 week, and the ALLO/IGF group received 10 μL of IGF I (100 ng/kg per day) intraperitoneally once a day for 1 week. Behavioral testing, sciatic nerve functional study and the gastrocnemius muscle mass showed earlier regeneration of axons in the ALLO/IGF group than in the ALLO group (P < 0.05). Administration of IGF I could accelerate functional recovery after nerve allografting in the sciatic nerve and may have clinical implications for the surgical management of patients after facial nerve transection.
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Mohammadi R, Mahmoodi H. Improvement of peripheral nerve regeneration following nerve repair by silicone tube filled with curcumin: A preliminary study in the rat model. Int J Surg 2013; 11:819-25. [DOI: 10.1016/j.ijsu.2013.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/22/2013] [Accepted: 08/18/2013] [Indexed: 12/11/2022]
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4
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Effect of local administration of insulin-like growth factor I combined with inside-out artery graft on peripheral nerve regeneration. Injury 2013; 44:1295-301. [PMID: 23747124 DOI: 10.1016/j.injury.2013.04.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/09/2013] [Accepted: 04/14/2013] [Indexed: 02/02/2023]
Abstract
The objective was to assess the effect of topically administered insulin-like growth factor (IGF I) on peripheral nerve regeneration and functional recovery. Eighty male healthy white Wistar rats were divided into four experimental groups (n=20), randomly: in transected group (TC), the left sciatic nerve was transected and stumps were fixed in the adjacent muscle. In treatment group, defect was bridged using an inside-out artery graft (IOAG/IGF) filled with 10 μL IGF I (100 ng/kg). In artery graft group (IOAG), the graft was filled with phosphate-buffered saline alone. In sham-operated group (SHAM), sciatic nerve was exposed and manipulated. Each group was subdivided into five subgroups of five animals each and regenerated nerve fibres were studied 4, 8, 12 and 16 weeks after surgery. Behavioural testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices confirmed faster recovery of regenerated axons in IOAG/IGF than IOAG group (P<0.05). In immunohistochemistry, location of reactions to S-100 in IOAG/IGF was clearly more positive than that in IOAG group. When loaded in an artery graft, IGF I accelerated and improved functional recovery and morphometric indices of sciatic nerve.
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5
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Kliem MA, Heeke BL, Franz CK, Radovitskiy I, Raore B, Barrow E, Snyder BR, Federici T, Kaye Spratt S, Boulis NM. Intramuscular administration of a VEGF zinc finger transcription factor activator (VEGF-ZFP-TF) improves functional outcomes in SOD1 rats. ACTA ACUST UNITED AC 2011; 12:331-9. [PMID: 21864053 DOI: 10.3109/17482968.2011.574142] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by motor neuron loss leading to paralysis and death. Vascular endothelial growth factor (VEGF) has angiogenic, neurotrophic, and neuroprotective properties, and has preserved neuromuscular function and protected motor neurons in rats engineered to overexpress the human gene coding the mutated G93A form of the superoxide dismutase-1 (SOD1). We assessed the effects of intramuscular administration of a plasmid that encodes a zinc finger protein transcription factor (ZFP-TF) engineered to induce VEGF expression in the SOD1 rat model of ALS. Weekly injections of the plasmid preserved ipsilateral hindlimb grip strength and markedly improved rotarod performance in SOD1 rats compared to the vehicle-treated group. The number of motor neurons and the proportion of innervated neuromuscular junctions were similar in both groups. In conclusion, our data suggest that administration of the VEGF-ZFP-TF may be neuroprotective and has potential as a safe and practical approach for the management of motor disability in ALS.
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Affiliation(s)
- Michele A Kliem
- Department of Neurosurgery , Emory University, Atlanta , Georgia, USA
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Abstract
IGF-I and -II are potent neuronal mitogens and survival factors. The actions of IGF-I and -II are mediated via the type I IGF receptor (IGF-IR) and IGF binding proteins regulate the bioavailability of the IGFs. Cell viability correlates with IGF-IR expression and intact IGF-I/IGF-IR signaling pathways, including activation of MAPK/phosphatidylinositol-3 kinase. The expression of IGF-I and -II, IGF-IR, and IGF binding proteins are developmentally regulated in the central and peripheral nervous system. IGF-I therapy demonstrates mixed therapeutic results in the treatment of peripheral nerve injury, neuropathy, and motor neuron diseases such as amyotrophic lateral sclerosis. In this review we discuss the role of IGFs during peripheral nervous system development and the IGF signaling system as the potential therapeutic target for the treatment of nerve injury and motor neuron diseases.
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Affiliation(s)
- Kelli A Sullivan
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109-2200, USA
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Meyer GE, Chesler L, Liu D, Gable K, Maddux BA, Goldenberg DD, Youngren JF, Goldfine ID, Weiss WA, Matthay KK, Rosenthal SM. Nordihydroguaiaretic acid inhibits insulin-like growth factor signaling, growth, and survival in human neuroblastoma cells. J Cell Biochem 2008; 102:1529-41. [PMID: 17486636 PMCID: PMC3001106 DOI: 10.1002/jcb.21373] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Neuroblastoma is a common pediatric malignancy that metastasizes to the liver, bone, and other organs. Children with metastatic disease have a less than 50% chance of survival with current treatments. Insulin-like growth factors (IGFs) stimulate neuroblastoma growth, survival, and motility, and are expressed by neuroblastoma cells and the tissues they invade. Thus, therapies that disrupt the effects of IGFs on neuroblastoma tumorigenesis may slow disease progression. We show that NVP-AEW541, a specific inhibitor of the IGF-I receptor (IGF-IR), potently inhibits neuroblastoma growth in vitro. Nordihydroguaiaretic acid (NDGA), a phenolic compound isolated from the creosote bush (Larrea divaricata), has anti-tumor properties against a number of malignancies, has been shown to inhibit the phosphorylation and activation of the IGF-IR in breast cancer cells, and is currently in Phase I trials for prostate cancer. In the present study in neuroblastoma, NDGA inhibits IGF-I-mediated activation of the IGF-IR and disrupts activation of ERK and Akt signaling pathways induced by IGF-I. NDGA inhibits growth of neuroblastoma cells and induces apoptosis at higher doses, causing IGF-I-resistant activation of caspase-3 and a large increase in the fraction of sub-G0 cells. In addition, NDGA inhibits the growth of xenografted human neuroblastoma tumors in nude mice. These results indicate that NDGA may be useful in the treatment of neuroblastoma and may function in part via disruption of IGF-IR signaling.
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Affiliation(s)
- Gary E. Meyer
- Department of Pediatrics, University of California, San Francisco, California
| | - Louis Chesler
- Department of Pediatrics, University of California, San Francisco, California
| | - Dandan Liu
- Department of Pediatrics, University of California, San Francisco, California
| | - Karissa Gable
- Diabetes and Endocrine Research, University of California, San Francisco/Mt. Zion Medical Center, San Francisco, California
| | - Betty A. Maddux
- Diabetes and Endocrine Research, University of California, San Francisco/Mt. Zion Medical Center, San Francisco, California
| | - David D. Goldenberg
- Department of Neurology, University of California, San Francisco, California
| | - Jack F. Youngren
- Diabetes and Endocrine Research, University of California, San Francisco/Mt. Zion Medical Center, San Francisco, California
| | - Ira D. Goldfine
- Diabetes and Endocrine Research, University of California, San Francisco/Mt. Zion Medical Center, San Francisco, California
| | - William A. Weiss
- Department of Neurology, University of California, San Francisco, California
| | | | - Stephen M. Rosenthal
- Department of Pediatrics, University of California, San Francisco, California
- Correspondence to: Stephen M. Rosenthal, MD, Division of Endocrinology, Department of Pediatrics, University of California, San Francisco, S672 513 Parnassus Ave., San Francisco, CA 94143.
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8
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Kim NH, Kim K, Park WS, Son HS, Bae Y. PKB/Akt inhibits ceramide-induced apoptosis in neuroblastoma cells by blocking apoptosis-inducing factor (AIF) translocation. J Cell Biochem 2008; 102:1160-70. [PMID: 17471535 DOI: 10.1002/jcb.21344] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Ceramide is a sphingolipid that is abundant in the plasma membrane of neuronal cells and is thought to have regulatory roles in cell differentiation and cell death. Ceramide is known to induce apoptosis in a variety of different cell types, whereas the physiological significance of gangliosides, another class of sphingolipids, in these processes is still unclear. We examined the mechanisms of ceramide-induced cell death using a human neuroblastoma cell line. Treatment of the human neuroblastoma cell line SH-SY5Y with ceramide induced dephosphorylation of the PKB/Akt kinase and subsequent mitochondrial dysfunction. In addition, ceramide-induced neuronal cell death was not completely blocked by inhibition of caspase activity. This incomplete inhibition appeared to be attributable to the translocation of apoptosis-inducing factor to the nucleus. Furthermore, overexpression of active PKB/Akt or Bcl-2 successfully blocked ceramide-induced neuronal cell death through inhibition of the translocation of apoptosis-inducing factor.
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Affiliation(s)
- Nam Hyun Kim
- Division of Specific Organ Cancer, Research Institute, National Cancer Center, Goyang, Republic of Korea
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9
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Schwab TS, Madison BB, Grauman AR, Feldman EL. Insulin-like growth factor-I induces the phosphorylation and nuclear exclusion of forkhead transcription factors in human neuroblastoma cells. Apoptosis 2007; 10:831-40. [PMID: 16133873 DOI: 10.1007/s10495-005-0429-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Akt-mediated phosphorylation of forkhead transcription factors is linked to growth factor-stimulated cell survival. We investigated whether the survival activity of insulin-like growth factor-I (IGF-I) in SH-SY5Y human neuroblastoma (NBL) cells is associated with phosphorylation and/or localization changes in forkhead proteins. IGF-I induced phosphorylation of Erks (p42/p44), FKHR (FOXO1a) (Ser 253), FKHRL1 (FOXO3a) (Ser 256), and Akt (Ser 473). PI3-K inhibitor, LY294002, reduced IGF-I-stimulated phosphorylation of FKHR, FKHRL1, and Akt, but did not affect Erk phosphorylation. Using a GFP-FKHR construct, FKHR imported into the nucleus during growth factor withdrawal-induced apoptosis. In addition, IGF-I rescue from serum withdrawal-induced apoptosis is associated with a rapid export of GFP-FKHR into the cytoplasm. Leptomycin B, an inhibitor of Crm1-mediated nuclear export, decreased the level of FKHRL1 phosphorylation in the presence of IGF-I in vector and FKHR overexpressing cells, but had no effect on the phosphorylation status of FKHR. In addition, leptomycin B prevented IGF-I stimulated nuclear export of GFP-FKHR. These studies show IGF-I phosphorylation of FKHR and FKHRL1 via a PI3-K-dependent pathway in NBL cells.
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Affiliation(s)
- T S Schwab
- Department of Neurology, University of Michigan, 4414 Kresge III, 200 Zina Pitcher Place, Ann Arbor, MI 48109, USA
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10
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Hyperosmotic stress-induced caspase-3 activation is mediated by p38 MAPK in the hippocampus. Brain Res 2007; 1186:1-11. [DOI: 10.1016/j.brainres.2007.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 10/02/2007] [Accepted: 10/05/2007] [Indexed: 01/13/2023]
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11
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Russo VC, Gluckman PD, Feldman EL, Werther GA. The insulin-like growth factor system and its pleiotropic functions in brain. Endocr Rev 2005; 26:916-43. [PMID: 16131630 DOI: 10.1210/er.2004-0024] [Citation(s) in RCA: 355] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In recent years, much interest has been devoted to defining the role of the IGF system in the nervous system. The ubiquitous IGFs, their cell membrane receptors, and their carrier binding proteins, the IGFBPs, are expressed early in the development of the nervous system and are therefore considered to play a key role in these processes. In vitro studies have demonstrated that the IGF system promotes differentiation and proliferation and sustains survival, preventing apoptosis of neuronal and brain derived cells. Furthermore, studies of transgenic mice overexpressing components of the IGF system or mice with disruptions of the same genes have clearly shown that the IGF system plays a key role in vivo.
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Affiliation(s)
- V C Russo
- Centre for Hormone Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia.
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12
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Silva RD, Sotoca R, Johansson B, Ludovico P, Sansonetty F, Silva MT, Peinado JM, Côrte-Real M. Hyperosmotic stress induces metacaspase- and mitochondria-dependent apoptosis inSaccharomyces cerevisiae. Mol Microbiol 2005; 58:824-34. [PMID: 16238630 DOI: 10.1111/j.1365-2958.2005.04868.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During the last years, several reports described an apoptosis-like programmed cell death process in yeast in response to different environmental aggressions. Here, evidence is presented that hyperosmotic stress caused by high glucose or sorbitol concentrations in culture medium induces in Saccharomyces cerevisiae a cell death process accompanied by morphological and biochemical indicators of apoptotic programmed cell death, namely chromatin condensation along the nuclear envelope, mitochondrial swelling and reduction of cristae number, production of reactive oxygen species and DNA strand breaks, with maintenance of plasma membrane integrity. Disruption of AIF1 had no effect on cell survival, but lack of Yca1p drastically reduced metacaspase activation and decreased cell death indicating that this death process was associated to activation of this protease. Supporting the involvement of mitochondria and cytochrome c in caspase activation, the mutant strains cyc1Deltacyc7Delta and cyc3Delta, both lacking mature cytochrome c, displayed a decrease in caspase activation associated to increased cell survival when exposed to hyperosmotic stress. These findings indicate that hyperosmotic stress triggers S. cerevisiae into an apoptosis-like programmed cell death that is mediated by a caspase-dependent mitochondrial pathway partially dependent on cytochrome c.
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Affiliation(s)
- Rui D Silva
- Departamento de Biologia-Centro de Biologia Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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13
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Teng Q, Garrity-Moses M, Federici T, Tanase D, Liu JK, Mazarakis ND, Azzouz M, Walmsley LE, Carlton E, Boulis NM. Trophic activity of Rabies G protein-pseudotyped equine infectious anemia viral vector mediated IGF-I motor neuron gene transfer in vitro. Neurobiol Dis 2005; 20:694-700. [PMID: 16005636 DOI: 10.1016/j.nbd.2005.05.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 04/25/2005] [Accepted: 05/02/2005] [Indexed: 11/20/2022] Open
Abstract
The present study examines gene delivery to cultured motor neurons (MNs) with the Rabies G protein (RabG)-pseudotyped lentiviral equine infectious anemia virus (RabG.EIAV) vector. RabG.EIAV-mediated beta-galactosidase (RabG.EIAV-LacZ) gene expression in cultured MNs plateaus 120 h after infection. The rate and percent of gene expression observed are titer-dependent (P < 0.001). The rat IGF-I cDNA sequence was then cloned into a RabG.EIAV vector (RabG.EIAV-IGF-I) and was shown to induce IGF-I expression in HEK 293 cells. MNs infected with RabG.EIAV-IGF-I demonstrate enhanced survival compared to MNs infected with RabG.EIAV-LacZ virus (P < 0.01). In addition, IGF-I expression in cultured MNs induced profound MN axonal elongation compared to control virus (P < 0.01). The enhanced motor neuron tropism of RabG.EIAV previously demonstrated in vivo, together with the trophic effects of RabG.EIAV-IGF-I MN gene expression may lend this vector to therapeutic application in motor neuron disease.
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Affiliation(s)
- Qingshan Teng
- Department of Neuroscience and Center for Neurological Restoration, Lerner Research Institute, Cleveland Clinic Foundation, NB2-126, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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14
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Bunn RC, King WD, Winkler MK, Fowlkes JL. Early developmental changes in IGF-I, IGF-II, IGF binding protein-1, and IGF binding protein-3 concentration in the cerebrospinal fluid of children. Pediatr Res 2005; 58:89-93. [PMID: 15774848 DOI: 10.1203/01.pdr.0000156369.62787.96] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
IGF-I and IGF-II are ubiquitously expressed growth factors that have profound effects on the growth and differentiation of many cell types and tissues, including cells of the CNS. In biologic fluids, most IGFs are bound to one of six IGF binding proteins (IGFBPs 1-6). Increasing evidence strongly supports a role for IGF-I in CNS development, as it promotes neuronal proliferation and survival. However, little is known about IGF-I and its homolog IGF-II and their carrier proteins, IGFBPs, during the neonatal period in which brain size increases dramatically, myelination takes place, and neurons show limited capacity to proliferate. Herein, we have determined the concentrations of IGF-I, IGF-II, IGFBP-1, and IGFBP-3 in cerebral spinal fluid (CSF) samples that were collected from children who were 1 wk to 18 y of age. The concentrations of IGF-I, IGFBP-1, and IGFBP-3 in CSF from children <6 mo of age were significantly higher than in older children, whereas IGF-II was higher in the older group. This is in contrast to what is observed in the peripheral circulation, where IGF-I and IGFBP-3 are low at birth and rise rapidly during the first year, reaching peak levels during puberty. Higher concentrations of IGF-I, IGFBP-1, and IGFBP-3 in the CSF of very young children suggest that these proteins might participate in the active processes of myelination and synapse formation in the developing nervous system. We propose that IGF-I and certain IGFBPs are likely necessary for normal CNS development during critical stages of neonatal brain growth and development.
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Affiliation(s)
- R Clay Bunn
- Arkansas Children's Hospital Research Institute, and Department of Pediatrics, University of Arkansas for Medical Sciences, 1120 Marshall Street, Little Rock, AR 72202, USA.
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15
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Meyer A, van Golen CM, Kim B, van Golen KL, Feldman EL. Integrin expression regulates neuroblastoma attachment and migration. Neoplasia 2005; 6:332-42. [PMID: 15256055 PMCID: PMC1502107 DOI: 10.1593/neo.03445] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neuroblastoma (NBL) is the most common malignant disease of infancy, and children with bone metastasis have a mortality rate greater than 90%. Two major classes of proteins, integrins and growth factors, regulate the metastatic process. We have previously shown that tumorigenic NBL cells express higher levels of the type I insulin-like growth factor receptor (IGF-IR) and that beta1 integrin expression is inversely proportional to tumorigenic potential in NBL. In the current study, we analyze the effect of beta1 integrin and IGF-IR on NBL cell attachment and migration. Nontumorigenic S-cells express high levels of beta1 integrin, whereas tumorigenic N-cells express little beta1 integrin. Alterations in beta1 integrin are due to regulation at the protein level, as translation is decreased in N-type cells. Moreover, inhibition of protein synthesis shows that beta1 integrin is degraded more slowly in S-type cells (SHEP) than in N-type cells (SH-SY5Y and IMR32). Inhibition of alpha5beta1 integrin prevents SHEP (but not SH-SY5Y or IMR32) cell attachment to fibronectin and increases SHEP cell migration. Increases in IGF-IR decrease beta1 integrin expression, and enhance SHEP cell migration, potentially through increased expression of alphavbeta3. These data suggest that specific classes of integrins in concert with IGF-IR regulate NBL attachment and migration.
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Affiliation(s)
- Amy Meyer
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | | | - Bhumsoo Kim
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Kenneth L. van Golen
- Department of Internal Medicine, Hematology and Oncology Division, University of Michigan, Ann Arbor, MI, USA
| | - Eva L. Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
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Kim B, Oh S, van Golen CM, Feldman EL. Differential regulation of insulin receptor substrate-1 degradation during mannitol and okadaic acid induced apoptosis in human neuroblastoma cells. Cell Signal 2004; 17:769-75. [PMID: 15722201 DOI: 10.1016/j.cellsig.2004.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Revised: 10/29/2004] [Accepted: 11/01/2004] [Indexed: 11/24/2022]
Abstract
Insulin receptor substrate (IRS) proteins are major docking molecules for the type I insulin like growth factor (IGF) receptor (IGF-IR) and mediate their effects on downstream signaling molecules. In this report, we investigated IRS-1 regulation during apoptosis in human neuroblastoma SH-EP cells. Treatment of SH-EP cells with mannitol or okadaic acid (OA) induces apoptosis with the typical characteristics of anoikis. Mannitol treatment results in IRS-1 degradation with concomitant appearance of smaller fragments, likely representing caspase cleavage products. In contrast OA-induced IRS-1 degradation is accompanied by a mobility shift in IRS-1, suggesting IRS-1 serine/threonine phosphorylation. Mannitol-induced, but not OA-induced, degradation is blocked by IGF-I. Pretreatment of the cells with caspase or proteasome inhibitors also partially blocks mannitol-induced IRS-1 degradation. These results suggest two independent pathways are involved in IRS-1 degradation; one pathway is dependent on caspase activation and is blocked by IGF-I, while a second pathway is caspase-independent and IGF-I-insensitive.
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Affiliation(s)
- Bhumsoo Kim
- Department of Neurology, University of Michigan, 4414 Kresge III, 200 Zina Pitcher Place, Ann Arbor, MI 48109-0588, United States
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17
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Nylandsted J, Jäättelä M, Hoffmann EK, Pedersen SF. Heat shock protein 70 inhibits shrinkage-induced programmed cell death via mechanisms independent of effects on cell volume-regulatory membrane transport proteins. Pflugers Arch 2004; 449:175-85. [PMID: 15340851 DOI: 10.1007/s00424-004-1332-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2004] [Accepted: 07/27/2004] [Indexed: 10/26/2022]
Abstract
Cell shrinkage is a ubiquitous feature of programmed cell death (PCD), but whether it is an obligatory signalling event in PCD is unclear. Heat shock protein 70 (Hsp70) potently counteracts PCD in many cells, by mechanisms that are incompletely understood. In the present investigation, we found that severe hypertonic stress greatly diminished the viability of murine fibrosarcoma cells (WEHI-902) and immortalized murine embryonic fibroblasts (iMEFs). This effect was attenuated markedly by Hsp70 over-expression. To determine whether the protective effect of Hsp70 was mediated via an effect on volume regulatory ion transport, we compared regulatory volume decrease (RVD) and increase (RVI) in control WEHI-902 cells and after increasing Hsp70 levels by heat shock or over-expression (WEHI-912). Hsp70 levels affected neither RVD, RVI nor the relative contributions of the Na(+)/H(+)-exchanger (NHE1) and Na(+),K(+),2Cl(-)-cotransporter (NKCC1) to RVI. Hypertonic stress induced caspase-3 activity in WEHI cells and iMEFs, an effect potentiated by Hsp70 in WEHI cells but inhibited by Hsp70 in iMEFs. Osmotic shrinkage-induced PCD was associated with Hsp70-inhibitable cysteine cathepsin release in iMEFs and attenuated by caspase and cathepsin inhibitors in WEHI cells. Treatment with TNF-alpha or the NHE1 inhibitor 5'-(N-ethyl-N-isopropyl)amiloride (EIPA) reduced the viability of WEHI cells further under isotonic and mildly, but not severely, hypertonic conditions. Thus, it is concluded that shrinkage-induced PCD involves both caspase- and cathepsin-dependent death mechanisms and is potently counteracted by Hsp70.
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Affiliation(s)
- J Nylandsted
- Apoptosis Laboratory, Danish Cancer Society, Strandboulevarden 49, 2100 Copenhagen O, Denmark
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Kim B, van Golen CM, Feldman EL. Degradation and dephosphorylation of focal adhesion kinase during okadaic acid-induced apoptosis in human neuroblastoma cells. Neoplasia 2004; 5:405-16. [PMID: 14670178 PMCID: PMC1502611 DOI: 10.1016/s1476-5586(03)80043-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Focal adhesion kinase (FAK) prevents apoptosis in many cell types. We have reported that tyrosine residues in FAK are dephosphorylated and FAK is degraded during mannitol-induced apoptosis in human neuroblastoma cells. Several studies suggest that FAK dephosphorylation and degradation are separate events. The current study defines the relationship between FAK dephosphorylation and degradation in neuroblastoma cells using okadaic acid (OA). OA, a serine phosphatase inhibitor, promotes serine/threonine phosphorylation, which in turn blocks tyrosine phosphorylation. OA induced focal adhesion loss, actin cytoskeleton disorganization, and cellular detachment, which corresponded to a loss of FAK Tyr397 phosphorylation. These changes preceded caspase-3 activation, Akt and MAP kinase activity loss, protein ubiquitination, and cellular apoptosis. Insulin-like growth factor-I prevented mannitol-induced, but not OA-induced, substrate detachment and FAK Tyr397 dephosphorylation, and the effects of OA on FAK Tyr397 phosphorylation were irreversible. The proteolytic degradation of FAK is temporally distinct from its tyrosine dephosphorylation, occurring when apoptotic pathways are already initiated and during a generalized destruction of signaling proteins. Therefore, agents resulting in the dephosphorylation of FAK may be beneficial for therapeutic treatment, irrespective of FAK protein levels, as this may result in apoptosis, which cannot be prevented by growth factor signaling.
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Affiliation(s)
- Bhumsoo Kim
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
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Vincent AM, Mobley BC, Hiller A, Feldman EL. IGF-I prevents glutamate-induced motor neuron programmed cell death. Neurobiol Dis 2004; 16:407-16. [PMID: 15193297 DOI: 10.1016/j.nbd.2004.03.001] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2003] [Revised: 02/20/2004] [Accepted: 03/05/2004] [Indexed: 10/26/2022] Open
Abstract
Insulin-like growth factor I (IGF-I) is currently in clinical trials for treatment of amyotrophic lateral sclerosis (ALS), but little is known about how it promotes the survival of motor neurons. In the current study, we examined IGF-I-mediated neuroprotection in an in vitro model of ALS utilizing enriched cultures of embryonic rat spinal cord motor neurons. IGF-I binds to the IGF-I receptor (IGF-IR) in motor neurons and activates MAPK and the downstream effector of phosphatidylinositol 3-kinase (PI-3K) signaling, Akt. IGF-I:IGF-IR signaling involves phosphorylation of IRS-1 and Shc, but not IRS-2. Glutamate, which is elevated in the cerebrospinal fluid of ALS patients, induced DNA fragmentation and caspase-3 cleavage in the spinal cord motor neurons. These effects of glutamate were blocked by co-treatment with IGF-I. However, a delay of IGF-I treatment for as little as 30 min eliminated its neuroprotective effect. Finally, alone, neither the MAPK pathway inhibitor PD98059 nor the PI-3K inhibitor LY294002 blocked the neuroprotective effect of IGF-I, but both inhibitors together were effective in this regard. These results suggest that the dose and timing of IGF-I administration are critical for producing a neuroprotective effect, and also suggest that both the MAPK and PI-3K/Akt pathways can promote the survival of motor neurons. We discuss our results in terms of novel strategies for ALS therapy.
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Affiliation(s)
- Andrea M Vincent
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
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20
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Leinninger GM, Russell JW, van Golen CM, Berent A, Feldman EL. Insulin-like growth factor-I regulates glucose-induced mitochondrial depolarization and apoptosis in human neuroblastoma. Cell Death Differ 2004; 11:885-96. [PMID: 15105834 DOI: 10.1038/sj.cdd.4401429] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Neuroblastoma, a pediatric peripheral nervous system tumor, frequently contains alterations in apoptotic pathways, producing chemoresistant disease. Insulin-like growth factor (IGF) system components are highly expressed in neuroblastoma, further protecting these cells from apoptosis. This study investigates IGF-I regulation of apoptosis at the mitochondrial level. Elevated extracellular glucose causes rapid mitochondrial enlargement coupled with an increase in the mitochondrial membrane potential (Delta Psi(M)) followed by mitochondrial membrane depolarization (MMD), uncoupling protein 3 (UCP3) downregulation, caspase-3 activation and decreased Bcl-2. MMD inhibition by Bongkrekic acid prevents high-glucose-induced loss of UCP3 and apoptosis. Glucose exposure induces caspase-9 cleavage within 30 min, and caspase-9 inhibition prevents glucose-mediated apoptosis. IGF-I prevents caspase activation and mitochondrial events leading to apoptosis. These results suggest that elevated glucose produces early initiator caspase activation, followed by Delta Psi(M) changes, in neuroblastoma cells; in turn, IGF-I prevents apoptosis by preventing downstream caspase activation, maintaining Delta Psi(M) and regulating Bcl proteins.
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Affiliation(s)
- G M Leinninger
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
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21
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Gazit V, Ben-Abraham R, Vofsi O, Katz Y. L-cysteine increases glucose uptake in mouse soleus muscle and SH-SY5Y cells. Metab Brain Dis 2003; 18:221-31. [PMID: 14567472 DOI: 10.1023/a:1025507216746] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous investigation demonstrated the potential of L-cysteine (L-Cys) at high concentrations to cause hypoglycemia in mice totally deprived of insulin. For further elucidation of the glucose-lowering mechanism, glucose uptake and quantity of glucose transporters (GLUTs 3 and 4) in mouse soleus muscle and C2C12 muscle cells, as well as in human SH-SY5Y neuroblastoma cells, were investigated. A marked enhancement of glucose uptake was demonstrated, peaking at 5.0 mM L-Cys in soleus muscle (P < 0.05) and SH-SY5Y cells (P < 0.001), respectively. In contrast, glucose uptake was not affected in the C2C12 muscle cells. Kinetic analysis of the SH-SY5Y glucose uptake showed a 2.5-fold increase in maximum transport velocity compared with controls (P < 0.001). In addition, both GLUT3 and GLUT4 levels were increased following exposure to L-Cys. Our findings point to a possible hypoglycemic effect of L-Cys.
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Affiliation(s)
- Vered Gazit
- Laboratory for Anesthesia, Pain and Neural Research, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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22
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Dmitrieva NI, Bulavin DV, Burg MB. High NaCl causes Mre11 to leave the nucleus, disrupting DNA damage signaling and repair. Am J Physiol Renal Physiol 2003; 285:F266-74. [PMID: 12684226 DOI: 10.1152/ajprenal.00060.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High NaCl causes DNA double-strand breaks and cell cycle arrest, but the mechanism of its genotoxicity has been unclear. In this study, we describe a novel mechanism that contributes to this genotoxicity. The Mre11 exonuclease complex is a central component of DNA damage response. This complex assembles at sites of DNA damage, where it processes DNA ends for subsequent activation of repair and initiates cell cycle checkpoints. However, this does not occur with DNA damage caused by high NaCl. Rather, following high NaCl, Mre11 exits from the nucleus, DNA double-strand breaks accumulate in the S and G2 phases of the cell cycle, and DNA repair is inhibited. Furthermore, the exclusion of Mre11 from the nucleus by high NaCl persists following UV or ionizing radiation, also preventing DNA repair in response to those stresses, as evidenced by absence of H2AX phosphorylation at places of DNA damage and by impaired repair of damaged reporter plasmids. Activation of chk1 by phosphorylation on Ser345 generally is required for DNA damage-induced cell cycle arrest. However, chk1 does not become phosphorylated during high NaCl-induced cell cycle arrest. Also, high NaCl prevents ionizing and UV radiation-induced phosphorylation of chk1, but cell cycle arrest still occurs, indicating the existence of alternative mechanisms for the S and G2/M delays. DNA breaks that occur normally during processes such as DNA replication and transcription, as well as damages to DNA induced by genotoxic stresses, ordinarily are rapidly repaired. We propose that inhibition of this repair by high NaCl results in accumulation of DNA damage, accounting for the genotoxicity of high NaCl, and that cell cycle delay induced by high NaCl slows accumulation of DNA damage until the DNA damage-response network can be reactivated.
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Affiliation(s)
- Natalia I Dmitrieva
- Laboratory of Kidney and Electrolyte Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bldg. 10, Rm. 6N260, Bethesda, MD 20892, USA.
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23
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Honma H, Podratz JL, Windebank AJ. Acute glucose deprivation leads to apoptosis in a cell model of acute diabetic neuropathy. J Peripher Nerv Syst 2003; 8:65-74. [PMID: 12795710 DOI: 10.1046/j.1529-8027.2003.03009.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Our aims were to better understand the mechanisms underlying peripheral neuropathy with diabetes mellitus and to test the hypothesis that acute lowering of glucose levels induces apoptosis in hypoxic neurons. METHODS We used rat dissociated dorsal root ganglion (DRG) neurons incubated in a medium high in glucose concentration (700 mg%) and room air (PO2 150 torr). After 5 days, DRG neurons were placed in hypoxic conditions (PO2 7.6 torr) with a normal-glucose (100 mg%) or high-glucose (700 mg%) medium containing 3 or 100 ng/mL of nerve growth factor. Acute lowering of glucose levels under hypoxic conditions led to apoptosis of DRG neurons. Apoptosis was demonstrated by bis-benzimide staining for nuclear fragmentation, electron microscopy, DNA laddering, and TUNEL staining. Caspase 3 immunocytochemistry and inhibition of neuronal death by the caspase inhibitor z-VAD-fmk (100 microM) confirmed that death was apoptotic. RESULTS Hypoxia-induced death was decreased when DRG neurons were maintained in high-glucose medium, suggesting that high levels of substrate protected against hypoxia. Apoptosis was completely prevented by increasing the concentration of nerve growth factor from 3 to 100 ng/mL and was partially prevented by the addition of the antioxidant alpha-lipoic acid (500 microM). CONCLUSIONS This model provides a novel means for studying the pathogenesis and treatment of early stages of diabetic neuropathy.
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Affiliation(s)
- Hiroyuki Honma
- Molecular Neuroscience PhD Program, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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24
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van Golen CM, Soules ME, Grauman AR, Feldman EL. N-Myc overexpression leads to decreased beta1 integrin expression and increased apoptosis in human neuroblastoma cells. Oncogene 2003; 22:2664-73. [PMID: 12730680 DOI: 10.1038/sj.onc.1206362] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neuroblastoma is a childhood tumor thought to arise through improper differentiation of neural crest cells. Increased N-Myc expression in neuroblastoma indicates highly malignant disease and poor patient prognosis. N-myc enhances cell growth, insulin-like growth factor type I receptor (IGF-IR) expression, and tumorigenicity in combination with Bcl-2. Despite these effects, N-Myc overexpression in SHEP neuroblastoma cells (SHEP/N-Myc cells) increases serum-withdrawal and mannitol-induced apoptosis. Although we have previously shown a protective effect of IGF-I in SHEP cells, in SHEP/N-Myc cells IGF-I rescue from mannitol-induced apoptosis is prevented. N-Myc overexpression has little effect on IGF-IR signaling pathways, but results in increased Akt phosphorylation when Bcl-2 is coexpressed. A loss of integrin-mediated adhesion promotes apoptosis in many systems. SHEP/N-Myc cells have dramatically less beta1 integrin expression than control cells, consistent with previous reports. beta1 integrin expression is decreased in more tumorigenic neuroblastoma cells lines, including IMR32 and SH-SY5Y cells. Reintroduction of beta1 integrin into the N-Myc-overexpressing cells prevents mannitol-mediated apoptosis. We speculate that N-Myc repression of beta1 integrin expression leads to a less differentiated phenotype, resulting in increased growth and tumorigenesis if properly supported or apoptosis if deprived of growth sustaining molecules.
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Affiliation(s)
- Cynthia M van Golen
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-0588, USA
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25
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Affiliation(s)
- Mireia Gómez-Angelats
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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26
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Nicolini G, Rigolio R, Scuteri A, Miloso M, Saccomanno D, Cavaletti G, Tredici G. Effect of trans-resveratrol on signal transduction pathways involved in paclitaxel-induced apoptosis in human neuroblastoma SH-SY5Y cells. Neurochem Int 2003; 42:419-29. [PMID: 12510025 DOI: 10.1016/s0197-0186(02)00132-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
trans-Resveratrol (3,4',5-trihydroxystilbene) is able to significantly reduce paclitaxel-induced apoptosis in the human neuroblastoma (HN) SH-SY5Y cell line, acting on several cellular signaling pathways that are involved in paclitaxel-induced apoptosis. trans-Resveratrol reverses phosphorylation of Bcl-2 induced by paclitaxel and concomitantly blocks Raf-1 phosphorylation, also observed after paclitaxel exposure, thus suggesting that Bcl-2 inactivation may be dependent on the activation of the Raf/Ras cascade. trans-Resveratrol also reverses the sustained phosphorylation of JNK/SAPK, which specifically occurs after paclitaxel exposure.Overall, our observations demonstrate that (a) the toxic action of paclitaxel on neuronal-like cells is not only related to the effect of the drug on tubulin, but also to its capacity to activate several intracellular pathways leading to inactivation of Bcl-2, thus causing cells to die by apoptosis, (b) trans-resveratrol significantly reduces paclitaxel-induced apoptosis by modulating the cellular signaling pathways which commit the cell to apoptosis.
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Affiliation(s)
- G Nicolini
- Dipartimento di Neuroscienze e Tecnologie Biomediche, Facoltá di Medicina e Chirurgia, Via Cadore 48, Università degli Studi di Milano-Bicocca, 20052 Monza, Italy
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27
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Yasuda H, Terada M, Maeda K, Kogawa S, Sanada M, Haneda M, Kashiwagi A, Kikkawa R. Diabetic neuropathy and nerve regeneration. Prog Neurobiol 2003; 69:229-85. [PMID: 12757748 DOI: 10.1016/s0301-0082(03)00034-0] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Diabetic neuropathy is the most common peripheral neuropathy in western countries. Although every effort has been made to clarify the pathogenic mechanism of diabetic neuropathy, thereby devising its ideal therapeutic drugs, neither convinced hypotheses nor unequivocally effective drugs have been established. In view of the pathologic basis for the treatment of diabetic neuropathy, it is important to enhance nerve regeneration as well as prevent nerve degeneration. Nerve regeneration or sprouting in diabetes may occur not only in the nerve trunk but also in the dermis and around dorsal root ganglion neurons, thereby being implicated in the generation of pain sensation. Thus, inadequate nerve regeneration unequivocally contributes to the pathophysiologic mechanism of diabetic neuropathy. In this context, the research on nerve regeneration in diabetes should be more accelerated. Indeed, nerve regenerative capacity has been shown to be decreased in diabetic patients as well as in diabetic animals. Disturbed nerve regeneration in diabetes has been ascribed at least in part to all or some of decreased levels of neurotrophic factors, decreased expression of their receptors, altered cellular signal pathways and/or abnormal expression of cell adhesion molecules, although the mechanisms of their changes remain almost unclear. In addition to their steady-state changes in diabetes, nerve injury induces injury-specific changes in individual neurotrophic factors, their receptors and their intracellular signal pathways, which are closely linked with altered neuronal function, varying from neuronal survival and neurite extension/nerve regeneration to apoptosis. Although it is essential to clarify those changes for understanding the mechanism of disturbed nerve regeneration in diabetes, very few data are now available. Rationally accepted replacement therapy with neurotrophic factors has not provided any success in treating diabetic neuropathy. Aside from adverse effects of those factors, more rigorous consideration for their delivery system may be needed for any possible success. Although conventional therapeutic drugs like aldose reductase (AR) inhibitors and vasodilators have been shown to enhance nerve regeneration, their efficacy should be strictly evaluated with respect to nerve regenerative capacity. For this purpose, especially clinically, skin biopsy, by which cutaneous nerve pathology including nerve regeneration can be morphometrically evaluated, might be a safe and useful examination.
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Affiliation(s)
- Hitoshi Yasuda
- Division of Neurology, Department of Medicine, Shiga University of Medical Science, Seta, Otsu, Japan.
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28
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Abstract
Apoptosis is a physiological form of death in which cells turn-on an intrinsic genetic program that eventually leads to their destruction in a highly regulated manner. This process renders elimination of "unwanted cells" in the body, and accounts for cellular turnover and homeostasis of tissues in multicellular organisms. Consequently, an imbalance in the apoptotic rate in a particular tissue can lead to profound effects in the whole organism. Exposure of cells to apoptotic stimuli induces a rapid loss of cell volume (apoptotic volume decrease) that plays a pivotal role in the decision of a cell to undergo apoptosis. Interestingly, the apoptotic volume decrease is driven by changes in ionic fluxes across the plasma membrane that promote a decrease in the intracellular ions that ultimately also leads to a reduction in intracellular ionic strength. Despite an intensive research effort however, the cellular and molecular mechanisms that trigger changes in cell volume during apoptosis remain poorly understood. Nevertheless, this apoptotic volume decrease has been shown to be a necessary component of the apoptotic cascade and an important point of modulation for the entire cell death process. In this review, we will focus on the importance of the apoptotic volume decrease in the context of signaling and modulation of programmed cell death.
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Affiliation(s)
- Mireia Gómez-Angelats
- The Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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29
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Kim B, Feldman EL. Insulin-like growth factor I prevents mannitol-induced degradation of focal adhesion kinase and Akt. J Biol Chem 2002; 277:27393-400. [PMID: 12011046 DOI: 10.1074/jbc.m201963200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In our laboratory, we are interested in hyperosmolarity-induced apoptosis in neuronal cells. We have shown that high concentrations of glucose or mannitol induce apoptotic cell death in dorsal root ganglia in culture and in SH-SY5Y and SH-EP human neuroblastoma cells. Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that has a critical role for transmitting integrin-mediated-signals. In this study, we report that hyperosmolar treatment mediates FAK dephosphorylation and cleavage, which is prevented by insulin-like growth factor I (IGF-I) treatment. Mannitol treatment of SH-EP cells transfected with vector (SH-EP/pSFFV) results in concentration- and time-dependent dephosphorylation and degradation of FAK. Dephosphorylation and degradation of FAK are tightly correlated with apoptotic morphological changes, including the disruption of actin stress fibers, the loss of focal adhesion sites, membrane blebbing, and cell detachment. Treatment of SH-EP/pSFFV cells with IGF-I or transfection of IGF-I receptor prevents these changes. Treatment of cells with pharmacologic inhibitors of the mitogen-activated protein kinase or phosphatidylinositol 3-kinase pathways does not affect mannitol-induced FAK dephosphorylation and degradation. However, phosphatidylinositol 3-kinase is necessary for IGF-I-mediated protection against FAK alteration. Mannitol treatment also results in the degradation of Akt. Mannitol induces the activation of caspases-3 and -9 in a time course similar to the dephosphorylation and degradation of FAK. Treatment of the cells with ZVAD, a general caspase inhibitor, blocks the mannitol-induced FAK and Akt degradation as well as cell detachment and apoptosis. These results suggest that one of the pathways of mannitol-mediated apoptosis is through the degradation of FAK and Akt and that IGF-I protects the cells from apoptosis by blocking the activation of caspases, which may be responsible for the loss of FAK and Akt.
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Affiliation(s)
- Bhumsoo Kim
- Department of Neurology, University of Michigan, 200 Zina Pitcher Place, Ann Arbor, MI 48109, USA
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30
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O'Donnell SL, Frederick TJ, Krady JK, Vannucci SJ, Wood TL. IGF-I and microglia/macrophage proliferation in the ischemic mouse brain. Glia 2002; 39:85-97. [PMID: 12112378 DOI: 10.1002/glia.10081] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have used a model of hypoxic-ischemic brain injury in adult male C57BL/6 mice to study insulin-like growth factor-I (IGF-I) and IGF-binding protein (IGFBP) expression in response to cerebral hypoxia-ischemia (H/I) in the adult mouse. A period of 20 min of H/I that resulted in histopathology in cortex, striatum, and thalamus was correlated with induction of mRNA for IGF-I, IGFBP-2, IGFBP-3, IGFBP-5, and glial fibrillary acidic protein (GFAP) by 4 days of recovery. Increased IGF-I mRNA was located within damaged regions and was surrounded by IGFBP-2 mRNA expression. The results of combined immunostaining/in situ hybridzation showed that the cells expressing IGFBP-2 mRNA were also GFAP-positive and comprised a subset of activated astrocytes immediately surrounding areas of damage. In contrast, staining within damaged regions showed high numbers of cells immunopositive for F4/80 and lectin B(4) indicative of microglia and macrophages but no cells immunopositive for the astrocytic proteins GFAP or S-100beta. Microglia/macrophages within the damaged areas expressed IGF-I mRNA and were also immunopositive for the proliferating cell nuclear antigen. To determine whether expression of IGF-I could contribute to proliferation of microglia, we treated purified cultures of adult brain microglia with IGF-I in the presence of (3)H-thymidine. IGF-I stimulated a twofold increase in DNA synthesis in cultures of adult brain microglia. Taken together with previous data demonstrating that IGF-I promotes proliferation of peripheral macrophages, these data support the hypothesis that IGF-I is an autocrine/paracrine mitogen for microglia/macrophages after H/I.
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Affiliation(s)
- Steven L O'Donnell
- Department of Neuroscience and Anatomy, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
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31
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Kim NS, Lee GM. Response of recombinant Chinese hamster ovary cells to hyperosmotic pressure: effect of Bcl-2 overexpression. J Biotechnol 2002; 95:237-48. [PMID: 12007864 DOI: 10.1016/s0168-1656(02)00011-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In an attempt to use the hyperosmotic pressure for improved foreign protein production in recombinant Chinese hamster ovary (rCHO) cells, the response of rCHO cells producing a humanized antibody (SH2-0.32-(Delta)bcl-2 cells) to hyperosmotic pressure was determined in regard to cell growth and death, and antibody production. Further, the feasibility of Bcl-2 overexpression in improving rCHO cell viability under hyperosmotic pressure was also determined by comparing control cells (SH2-0.32-(Delta)bcl-2) with Bcl-2 overexpressing cells (14C6-bcl-2). After 3 days of cultivation in the standard medium (294 mOsm x kg(-1)), the spent medium was exchanged with the fresh media with various osmolalities (294-640 mOsm x kg(-1)). The results obtained show that hyperosmotic pressure inhibited cell growth in a dose-dependent manner, though 14C6-bcl-2 cells were less susceptible to hyperosmotic pressure than SH2-0.32-(Delta)bcl-2 cells. At 522 mOsm x kg(-1), SH2-0.32-(Delta)bcl-2 cells underwent a gradual cell death mainly through apoptosis due to the cytotoxic effect of hyperosmotic pressure. In contrast, Bcl-2 overexpression in 14C6-bcl-2 cells could delay the apoptosis induced by 522 mOsm x kg(-1) by inhibiting caspase-3 activation. Bcl-2 overexpression could also improve the cellular membrane integrity of 14C6-bcl-2 cells. When subjected to hyperosmotic pressure, the specific antibody productivity of SH2-0.32-(Delta)bcl-2 cells and 14C6-bcl-2 cells was increased in a similar extent. As a result, the final antibody concentration achieved in 14C6-bcl-2 cells at 522 mOsm x kg(-1) was 2.5-fold higher than that at 294 mOsm x kg(-1). At 580 mOsm x kg(-1), acute hyperosmotic pressure induced the rapid loss of viability in both SH2-0.32-(Delta)bcl-2 and 14C6-bcl-2 cells through necrosis rather than through apoptosis. Taken together, Bcl-2 overexpression and optimized hyperosmotic pressure could improve the antibody production of rCHO cells.
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Affiliation(s)
- No Soo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1 Kusong-Dong, Yusong-Gu, 305-701, Taejon, Republic of Korea
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32
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Dmitrieva NI, Michea LF, Rocha GM, Burg MB. Cell cycle delay and apoptosis in response to osmotic stress. Comp Biochem Physiol A Mol Integr Physiol 2001; 130:411-20. [PMID: 11913454 DOI: 10.1016/s1095-6433(01)00439-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
As part of the urinary concentrating mechanism, renal inner medulla cells may be exposed to extremely variable NaCl and urea concentrations that can reach very high levels. A number of studies, reviewed herein, aim to understand how such osmotic stress affects the cells and what protective mechanisms might exist. The majority of these studies are done on inner medullary epithelial cells that grow continuously in tissue culture (mIMCD3). Cells grown at 300 mosmol/kg survive increase to 500 mosmol/kg by adding NaCl or urea, but only after a growth arrest of approximately 24 h. At a higher osmolality (650-700 mosmol/kg) most cells die within hours by apoptosis. The cells both in vitro and in vivo adapt to high osmolality by a number of mechanisms, including accumulation of variety of organic osmolytes and induction of heat shock proteins. The cell cycle delay results from blocks at the G1 and G2/M checkpoints and slowing during S. After adding NaCl, but not urea, the amount and transcriptional activity of p53 (the tumor suppressor protein) increases. The p53 is phosphorylated on ser-15 and is transcriptionally active at 500 mosmol/kg (associated with cell survival), but not at 700 mosmol/kg (associated with apoptosis). Reduction of p53 expression by p53 antisense oligonucleotide increases sensitivity of renal cells in culture to hyperosmotic stress caused by NaCl. The possible mechanisms of the protection action of p53 against hypertonic stress are discussed.
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Affiliation(s)
- N I Dmitrieva
- Laboratory of Kidney and Electrolyte Metabolism, National Heart, Lung and Blood Institute, Bethesda, MD 20892-1603, USA
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33
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Ostlund P, Lindegren H, Pettersson C, Bedecs K. Up-regulation of functionally impaired insulin-like growth factor-1 receptor in scrapie-infected neuroblastoma cells. J Biol Chem 2001; 276:36110-5. [PMID: 11461928 DOI: 10.1074/jbc.m105710200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A growing body of evidence suggests that an altered level or function of the neurotrophic insulin-like growth factor-1 receptor (IGF-1R), which supports neuronal survival, may underlie neurodegeneration. This study has focused on the expression and function of the IGF-1R in scrapie-infected neuroblastoma cell lines. Our results show that scrapie infection induces a 4-fold increase in the level of IGF-1R in two independently scrapie-infected neuroblastomas, ScN2a and ScN1E-115 cells, and that the increased IGF-1R level was accompanied by increased IGF-1R mRNA levels. In contrast to the elevated IGF-1R expression in ScN2a, receptor binding studies revealed an 80% decrease in specific (125)I-IGF-1-binding sites compared with N2a cells. This decrease in IGF-1R-binding sites was shown to be caused by a 7-fold decrease in IGF-1R affinity. Furthermore, ScN2a showed no significant difference in IGF-1 induced proliferative response, despite the noticeable elevated IGF-1R expression, putatively explained by the reduced IGF-1R binding affinity. Additionally, IGF-1 stimulated IGF-1Rbeta tyrosine phosphorylation showed no major change in the dose-response between the cell types, possibly due to altered tyrosine kinase signaling in scrapie-infected neuroblastoma cells. Altogether these data indicate that scrapie infection affects the expression, binding affinity, and signal transduction mediated by the IGF-1R in neuroblastoma cells. Altered IGF-1R expression and function may weaken the trophic support in scrapie-infected neurons and thereby contribute to neurodegeneration in prion diseases.
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Affiliation(s)
- P Ostlund
- Department of Neurochemistry and Neurotoxicology, University of Stockholm, Svante Arrhenius v. 21A, S-10691 Stockholm, Sweden
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34
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Stoothoff WH, Johnson GV. Hyperosmotic stress-induced apoptosis and tau phosphorylation in human neuroblastoma cells. J Neurosci Res 2001; 65:573-82. [PMID: 11550225 DOI: 10.1002/jnr.1187] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A characteristic hallmark of Alzheimer's disease brain is the presence of hyperphosphorylated tau; however, the mechanisms responsible for the aberrant tau phosphorylation are unknown. Recently, it has been shown that apoptotic-like processes may be involved in some of the neuronal loss in Alzheimer's disease. In consideration of these findings, the relationship between tau phosphorylation and apoptosis was examined in human neuroblastoma SH-SY5Y cells that were subjected to hyperosmotic stress. In this model caspase 3 activity, which served as an indicator of apoptosis, was increased by 30 min of osmotic stress and remained elevated through 4 hr. Hyperosmotic stress also resulted in a robust increase in tau phosphorylation at both Ser/Pro and non-Ser/Pro sites. Phosphorylation of Ser262/356 (12E8) and Ser396/404 (PHF-1) increased by 5 min and remained elevated for at least 1 hr. In contrast, phosphorylation within the Tau-1 epitope did not increase (as evidenced by decreased immunoreactivity) until 30 min after treatment but remained elevated for a much greater period of time. Treatment with insulin-like growth factor-1 delayed but did not prevent apoptotic cell death induced by osmotic stress and attenuated the increase in phosphorylation at the Tau-1 epitope. Li(+), an inhibitor of glycogen synthase kinase 3 beta, had no effect on osmotic stress-induced caspase activation, but reduced phosphorylation at the Tau-1 epitope. Complete inhibition of osmotic stress-induced caspase activation with DEVD-CHO had no effect on the increases in tau phosphorylation. The results of these studies demonstrate that tau phosphorylation is increased at the specific epitopes during apoptosis. However, the changes in tau phosphorylation likely do not significantly impact the apoptotic process but rather occur concurrently as a result of inappropriate activation of specific protein kinases. Nonetheless, there is increasing evidence of a dysregulation of protein kinases that occurs in Alzheimer's disease brain that may be part of the events of apoptosis, which could contribute to aberrant increases in tau phosphorylation.
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Affiliation(s)
- W H Stoothoff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama 35924-0017, USA
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35
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Delaney CL, Russell JW, Cheng HL, Feldman EL. Insulin-like growth factor-I and over-expression of Bcl-xL prevent glucose-mediated apoptosis in Schwann cells. J Neuropathol Exp Neurol 2001; 60:147-60. [PMID: 11273003 DOI: 10.1093/jnen/60.2.147] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Schwann cells (SCs), the myelinating cells of the peripheral nervous system, are lost or damaged in patients suffering from diabetic neuropathy. In the current study, 2 model systems are used to study the mechanism of SC damage in diabetic neuropathy: the streptozotocin (STZ)-treated diabetic rat and cultures of purified SCs in vitro. Electron microscopy of dorsal root ganglia from STZ-treated rats reveals classic ultrastructural features of apoptosis in SCs, including chromatin clumping and prominent vacuolation. Bisbenzamide staining of SCs cultured in hyperglycemic defined media shows nuclear blebbing of apoptotic cells. Insulin-like growth factor-I (IGF-I) is protective. LY294002, a phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, blocks the effect of IGF-I. High glucose induces caspase cleavage in apoptotic SCs--an effect that is blocked by bok-asp-fmk (BAF), a caspase inhibitor. Although Bcl-xL expression remains unchanged in experimental conditions, over-expression of Bcl-xL protects SCs from apoptosis. In summary, hyperglycemia induces caspase activation and morphologic changes in SCs consistent with apoptotic death, both in vivo and in vitro. Over-expression of Bcl-xL, or IGF-I, signaling via PI 3-kinase, protects SCs from glucose-mediated apoptosis in vitro. IGF-I may be useful in preventing hyperglycemia-induced damage to SCs in patients suffering from diabetic neuropathy.
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Affiliation(s)
- C L Delaney
- Department of Neurology, University of Michigan, Ann Arbor, USA
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36
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Cheng HL, Steinway ML, Xin X, Feldman EL. Insulin-like growth factor-I and Bcl-X(L) inhibit c-jun N-terminal kinase activation and rescue Schwann cells from apoptosis. J Neurochem 2001; 76:935-43. [PMID: 11158266 DOI: 10.1046/j.1471-4159.2001.00110.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We previously reported that Schwann cells undergo apoptosis after serum withdrawal. Insulin-like growth factor-I, via phosphatidylinositol-3 kinase, inhibits caspase activation and rescues Schwann cells from serum withdrawal-induced apoptosis. In this study, we examined the role of c-jun N-terminal protein kinase (JNK) in Schwann cell apoptosis induced by serum withdrawal. Activation of both JNK1 and JNK2 was detected 1 h after serum withdrawal with the maximal level detected at 2 h. A dominant negative JNK mutant, JNK (APF), blocked JNK activation induced by serum withdrawal and Schwann cell apoptosis, suggesting JNK activation participates in Schwann cell apoptosis. Serum withdrawal-induced JNK activity was caspase dependent and inhibited by a caspase 3 inhibitor, Ac-DEVD-CHO. Because insulin-like growth factor-I and Bcl-X(L) are both Schwann cell survival factors, we tested their effects on JNK activation during apoptosis. Insulin-like growth factor-I treatment decreased both JNK1 and JNK2 activity induced by serum withdrawal. LY294002, a phosphatidylinositol-3 kinase inhibitor, blocked insulin-like growth factor-I inhibition on JNK activation, suggesting that phosphatidylinositol-3 kinase mediates the effects of insulin-like growth factor-I. Overexpression of Bcl-X(L) also resulted in less Schwann cell death and inhibition of JNK activation after serum withdrawal. Collectively, these results suggest JNK activation is involved in Schwann cell apoptosis induced by serum withdrawal. Insulin-like growth factor-I and Bcl family proteins rescue Schwann cells, at least in part, by inhibition of JNK activity.
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Affiliation(s)
- H L Cheng
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
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37
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van Golen CM, Castle VP, Feldman EL. IGF-I receptor activation and BCL-2 overexpression prevent early apoptotic events in human neuroblastoma. Cell Death Differ 2000; 7:654-65. [PMID: 10889510 DOI: 10.1038/sj.cdd.4400693] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The type I insulin-like growth factor receptor (IGF-IR) is important for mitogenesis, transformation, and survival of tumor cells. The current study examines the effect of IGF-IR expression and activation on apoptosis in SHEP human neuroblastoma cells. SHEP cells undergo apoptosis which is prevented by IGF-I addition or overexpression of the IGF-IR (SHEP/IGF-IR cells). High mannitol treatment activates caspase-3 by 1 h in SHEP cells while caspase-3 activation is delayed by 3 h in SHEP/IGF-IR cells. Transfection with Bcl-2 (SHEP/Bcl-2 cells) prevents serum withdrawal and mannitol induced apoptosis and caspase-3 activation. Mannitol induces mitochondrial membrane depolarization in both SHEP and SHEP/IGF-IR cells. IGF-IR activation or overexpression of Bcl-2 in SHEP cells prevents mitochondrial membrane depolarization. Collectively, these results suggest that IGF-IR or Bcl-2 overexpression in neuroblastoma cells promotes cell survival by preventing mitochondrial membrane depolarization and caspase-3 activation, ultimately leading to increased tumor growth.
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Affiliation(s)
- C M van Golen
- Department of Neurology and Neuroscience Program, University of Michigan, Ann Arbor, Michigan 48109-0588, USA
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38
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Tanii H, Ankarcrona M, Flood F, Nilsberth C, Mehta ND, Perez-Tur J, Winblad B, Benedikz E, Cowburn RF. Alzheimer's disease presenilin-1 exon 9 deletion and L250S mutations sensitize SH-SY5Y neuroblastoma cells to hyperosmotic stress-induced apoptosis. Neuroscience 2000; 95:593-601. [PMID: 10658639 DOI: 10.1016/s0306-4522(99)00432-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mutations in the presenilin-1 (PS1) and presenilin-2 (PS2) genes account for the majority of early-onset familial Alzheimer's disease cases. Recent studies suggest that presenilin gene mutations predispose cells to apoptosis by mechanisms involving altered calcium homeostasis and oxidative damage. In the present study, we determined whether PS1 mutations also sensitize cells to hyperosmotic stress-induced apoptosis. For this, we established SH-SY5Y neuroblastoma cell lines stably transfected with wild-type PS1 or either the PS1 exon 9 deletion (deltaE9) or PS1 L250S mutants. Cultured cells were exposed to an overnight (17 h) serum deprivation, followed by a 30 min treatment with either 20 mM glucose, 10 nM insulin-like growth factor-1 or 20 mM glucose + 10 nM insulin-like growth factor-1. Cells were then cultured for a further 3, 6 or 24 h and stained for apoptotic condensed nuclei using propidium iodide. Confirmation that cells were undergoing an active apoptotic process was achieved by labelling of DNA strand breaks using the terminal dUTP nick end labelling (TUNEL) technique. We also determined cell viability using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Propidium iodide staining revealed that all cell lines and controls showed an increased number of apoptotic cells appearing with condensed nuclei at 24 h compared with 6 h and 3 h. High glucose-induced hyperosmotic stress resulted in significantly more apoptotic cells in the PS1 deltaE9 and PS1 L250S mutation cell lines at 24 h, compared with the wild-type PS1 lines (P < 0.001, ANOVA for both comparisons). Mean values (+/-S.D.) for the percentage number of apoptotic cells at 24 h following high glucose treatment were 16.1 +/- 3.5%, 26.7 +/- 5.5% and 31.0 +/- 5.7% for the wild-type PS1, PS1 deltaE9 and PS1 L250S lines, respectively. The pro-apoptotic effects of high glucose treatment were reversed by 10 nM insulin-like growth factor-1, although to a lesser extent in the mutation cell lines (5.8 +/- 2.4%, 15.2 +/- 7.3% and 13.2 +/- 2.0% for the wild-type PS1, PS1 deltaE9 (P < 0.01 for comparison with wild-type PS1) and PS1 L250S (P < 0.01 for comparison with wild-type PS1) transfected lines, respectively. TUNEL labelling of cells at 24 h following treatment gave essentially the same results pattern as obtained using propidium iodide. The percentage number of apoptotic cells with DNA strand breaks (means +/- S.D.) following high glucose treatment was 15.4 +/- 2.6% for the wild-type PS1, 26.8 +/- 3.2% for the PS1 deltaE9 (P < 0.001 for comparison with wild-type PS1) and 29.7 +/- 6.1% for the PS1 L250S transfected lines (P < 0.001 for comparison with wild-type PS1). The PS1 deltaE9 and PS1 L250S transfected lines also showed a higher number of apoptotic cells with DNA strand breaks at 24 h following high glucose plus insulin-like growth factor-1 treatment (11.4 +/- 2.0% and 14.3 +/- 2.8%, respectively), compared with values for the wild-type PS1 lines (8.5 +/- 2.4%). These differences were significant (P < 0.01) for the comparison of wild-type PS1 and PS1 L250S, but not PS1 deltaE9 lines. The mutation-related increases in number of apoptotic cells at 24 h following high glucose treatment were not accompanied by significant differences in cell viability at this time-point. Our results indicate that PS1 mutations predispose to hyperosmotic stress-induced apoptosis and that the anti-apoptotic effects of insulin-like growth factor-1 are compromised by these mutations. Perturbations of insulin-like growth factor-1 signalling may be involved in PS1 mutation-related apoptotic neuronal cell death in Alzheimer's disease.
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Affiliation(s)
- H Tanii
- Karolinska Institutet, Department of Geriatric Medicine, Huddinge, Sweden
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Van Golen CM, Feldman EL. Insulin-like growth factor I is the key growth factor in serum that protects neuroblastoma cells from hyperosmotic-induced apoptosis. J Cell Physiol 2000; 182:24-32. [PMID: 10567913 DOI: 10.1002/(sici)1097-4652(200001)182:1<24::aid-jcp3>3.0.co;2-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Neuroblastoma is a childhood tumor of the peripheral nervous system that remains largely uncurable by conventional methods. Mannitol induces apoptosis in neuroblastoma cell types and insulin-like growth factor I (IGF-I) protects these cells from hyperosmotic-induced apoptosis by affecting apoptosis-regulatory proteins. In the current study, we investigate factors that enable SH-SY5Y neuroblastoma cells to survive in the presence of an apoptotic stimulus. When SH-SY5Y cells are exposed to high mannitol concentrations, more than 60% of the cells are apoptotic within 48 h. Normal CS prevents hyperosmotic-induced apoptosis in a dose-dependent manner, with 0.6% CS protecting 50% of the cells, and 3% CS rescuing more than 70% of the cells from apoptosis. Serum also delays the commitment point for SH-SY5Y cells from 9 h to 35 h. A survey of several growth factors, including epidermal growth factor (EGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), fibroblast growth factor (FGF), and IGF-I reveals that IGF-I is a component of serum necessary for protection of neuroblastoma cells from death. Mitochondrial membrane depolarization occurs in greater than 40% of the cells after mannitol exposure and caspase-3 activation is increased in high mannitol conditions after 9 h. IGF-I blocks both the mitochondrial membrane depolarization and caspase-3 activation normally induced by hyperosmotic treatment in neuroblastoma cells. Our results suggest that (1) IGF-I is a key factor in serum necessary for protection from death and (2) IGF-I acts upstream from the mitochondria and the caspases to prevent apoptosis in human neuroblastoma.
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Affiliation(s)
- C M Van Golen
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
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40
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Delaney CL, Cheng HL, Feldman EL. Insulin-like growth factor-I prevents caspase-mediated apoptosis in Schwann cells. JOURNAL OF NEUROBIOLOGY 1999; 41:540-8. [PMID: 10590177 DOI: 10.1002/(sici)1097-4695(199912)41:4<540::aid-neu9>3.0.co;2-p] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Both neurons and glia succumb to programmed cell death (PCD) when deprived of growth factors at critical periods in development or following injury. Insulin-like growth factor-I (IGF-I) prevents apoptosis in neurons in vitro. To investigate whether IGF-I can protect Schwann cells (SC) from apoptosis, SC were harvested from postnatal day 3 rats and maintained in serum-containing media until confluency. When cells were switched to serum-free defined media (DM) for 12-72 h, they underwent PCD. Addition of insulin or IGF-I prevented apoptosis. Bisbenzamide staining revealed nuclear condensation and formation of apoptotic bodies in SC grown in DM alone, but SC grown in DM plus IGF-I had normal nuclear morphology. The phosphatidylinositol 3-kinase (PI 3-K) inhibitor LY294002 blocked IGF-I-mediated protection. Caspase-3 activity was rapidly activated upon serum withdrawal in SC, and the caspase inhibitor BAF blocked apoptosis. These results suggest that IGF-I rescues SC from apoptosis via PI 3-K signaling which is upstream from caspase activation.
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Affiliation(s)
- C L Delaney
- Department of Neurology, University of Michigan, 200 Zina Pitcher Place, 4414 Kresge III, Ann Arbor, Michigan 48109, USA
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41
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Russell JW, Sullivan KA, Windebank AJ, Herrmann DN, Feldman EL. Neurons undergo apoptosis in animal and cell culture models of diabetes. Neurobiol Dis 1999; 6:347-63. [PMID: 10527803 DOI: 10.1006/nbdi.1999.0254] [Citation(s) in RCA: 299] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Recent clinical trials indicate that the severity of diabetic neuropathy is correlated with the level of patient glycemic control. In the current study, hyperglycemia induces apoptotic changes in dorsal root ganglion neurons and Schwann cells in vivo both in streptozotocin-treated diabetic rats and in rats made acutely hyperglycemic with infused glucose. Typical apoptotic nuclear and cytoplasmic changes are observed. In addition mitochondrial changes recently reported to occur as part of the apoptotic cascade, such as ballooning of mitochondria and disruption of the internal cristae, are seen in diabetic dorsal root ganglion neurons and Schwann cells. Similar changes have been reported in neurons in the presence of oxidative stress. In order to study the neurotoxic effects of high glucose we developed an in vitro model using rat dorsal root ganglion neurons. In dorsal root ganglion cultured in defined medium, addition of moderate glucose levels results in neurite degeneration and apoptosis. These changes are coupled with activation of caspase-3, dependent on the concentration of glucose. The apoptotic changes observed in vitro are similar to those observed in vivo. In contrast, addition of IGF-I, even at physiological concentrations, prevents activation of caspase-3 and neuronal apoptosis in vitro. We suggest that oxidative stress may promote the mitochondrial changes in diabetic animals and lead to activation of programmed cell death caspase pathways. These results imply a new pathogenetic mechanism for diabetic sensory neuropathy.
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Affiliation(s)
- J W Russell
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109, USA
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42
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Isgaard J, Tivesten A. The role of growth hormone and insulin-like growth factor I in the regulation of apoptosis. Growth Horm IGF Res 1999; 9 Suppl A:125-128. [PMID: 10429896 DOI: 10.1016/s1096-6374(99)80025-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- J Isgaard
- Research Center for Endocrinology and Metabolism, Sahlgrenska University Hospital, Göteborg, Sweden.
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43
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Cheng HL, Feldman EL. Bidirectional regulation of p38 kinase and c-Jun N-terminal protein kinase by insulin-like growth factor-I. J Biol Chem 1998; 273:14560-5. [PMID: 9603971 DOI: 10.1074/jbc.273.23.14560] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that insulin-like growth factor I (IGF-I) activation of the IGF-I receptor rescues SH-SY5Y human neuroblastoma cells from high glucose-mediated programmed cell death (PCD). In the current study, we further explored the potential points in the cell death cascade where IGF-I receptor activation may afford neuroprotection. As an initial step, we examined the effects of the PCD stimulus, high glucose, on stress-activated protein kinases, specifically the two mitogen-activated protein kinases p38 kinase and c-Jun N-terminal kinase (JNK). High glucose treatment activated the tyrosine phosphorylation of both p38 kinase and JNK in a dose- and time-dependent fashion. We next examined the effects of IGF-I on JNK and p38 kinase under normoglycemic and hyperglycemic conditions. IGF-I activated p38 kinase alone and had additive effects on glucose-induced p38 kinase phosphorylation. In contrast, IGF-I inhibited glucose activation of JNK phosphorylation and JNK activity. IGF-I also inhibited the glucose-induced nuclear translocation of JNK, but did not effect glucose-induced translocation of p38 kinase. Finally, IGF-I inhibition of JNK phosphorylation was blocked by the mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, PD98059. Collectively, these data imply cross-talk between the mitogen-activated protein kinase pathway and JNK and suggest that IGF-I activation of mitogen-activated protein kinases interferes with JNK activation and protects cells from PCD.
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Affiliation(s)
- H L Cheng
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, USA
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44
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Dennis PA, Kastan MB. Cellular survival pathways and resistance to cancer therapy. Drug Resist Updat 1998; 1:301-9. [PMID: 17092811 DOI: 10.1016/s1368-7646(98)80046-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/1998] [Revised: 06/09/1998] [Accepted: 06/09/1998] [Indexed: 11/18/2022]
Abstract
Chemotherapy and irradiation induce programmed cell death (apoptosis) in their target cells. Dysregulated apoptosis is a feature that is selected for during tumor formation and contributes to therapeutic resistance. Cell survival in the face of cytotoxic therapy is dictated by both internal properties of the cell, such as status of components of the apoptotic machinery, and its extracellular milieu, such as extracellular matrix (ECM) and growth factor receptor expression and signaling. The importance of extracellular survival signals as key regulators of apoptosis is now being recognized by the ability of growth factors (GFs), GF receptors (GFRs), and GFR signaling to promote cellular survival. GFs can mitigate or abrogate the effectiveness of cancer therapy and protect against other cellular insults. Because survival signals generated by different extracellular sources converge at key molecules, new molecular targets have been identified which could be exploited to maximize the effectiveness of cytotoxic cancer therapy.
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Affiliation(s)
- P A Dennis
- Division of Experimental Therapeutics and Pharmacology, Johns Hopkins Oncology Center, Baltimore, MD, USA
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45
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Feldman EL, Sullivan KA, Kim B, Russell JW. Insulin-like growth factors regulate neuronal differentiation and survival. Neurobiol Dis 1997; 4:201-14. [PMID: 9361296 DOI: 10.1006/nbdi.1997.0156] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Insulin-like growth factor I (IGF-I) and IGF-II are potent trophic factors for motor and sensory neurons and glial cells. The actions of IGF-I and IGF-II are mediated via the IGF-I receptor (IGF-IR). IGF:IGF-IR binding activates distinct signaling cascades, which in turn mediate the trophic effects of the IGFs. We discuss three main IGF coupled events: growth cone motility, long-term neurite outgrowth, and neuroprotection. Our data suggest that IGF-I enhances growth cone motility by promoting reorganization of actin and activation of focal adhesion proteins via the phosphatidylinositol-3 kinase (Pl-3K) pathway. Long-term treatment with IGF-I activates the mitogen-activated protein (MAP) kinase cascade and promotes neurite outgrowth. A separable, but likely linked, action of the IGFs via Pl-3K is protection of neurons from apoptosis. These pleotrophic effects of IGFs suggest that this family of growth factors may have potential clinical utility in the treatment of neurological disorders.
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Affiliation(s)
- E L Feldman
- Department of Neurology, University of Michigan, Ann Arbor 48109, USA
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