1
|
Yao YY, Ling EA, Lu D. Microglia mediated neuroinflammation - signaling regulation and therapeutic considerations with special reference to some natural compounds. Histol Histopathol 2020; 35:1229-1250. [PMID: 32662061 DOI: 10.14670/hh-18-239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Neuroinflammation plays a central role in multiple neurodegenerative diseases and neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), cerebral ischemic injury etc. In this connection, microglia, the key players in the central nervous system, mediate the inflammatory response process. In brain injuries, activated microglia can clear the cellular debris and invading pathogens and release neurotrophic factors; however, prolonged microglia activation may cause neuronal death through excessive release of inflammatory mediators. Therefore, it is of paramount importance to understand the underlying molecular mechanisms of microglia activation to design an effective therapeutic strategy to alleviate neuronal injury. Recent studies have shown that some natural compounds and herbal extracts possess anti-inflammatory properties that may suppress microglial activation and ameliorate neuroinflammation and hence are neuroprotective. In this review, we will update some of the common signaling pathways that regulate microglia activation. Among the various signaling pathways, the Notch-1, mitogen-activated protein kinases (MAPKs), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) have been reported to exacerbate microglia mediated neuroinflammation that is implicated in different neuropathological diseases. The search for natural compounds or agents, specifically those derived from natural herbal extracts such as Gastrodin, scutellarin, RG1 etc. has been the focus of many of our recent studies because they have been found to regulate microglia activation. The pharmacological effects of these agents and their potential mechanisms for regulating microglia activation are systematically reviewed here for a fuller understanding of their biochemical action and therapeutic potential for treatment of microglia mediated neuropathological diseases.
Collapse
Affiliation(s)
- Yue-Yi Yao
- Technology Transfer Center, Kunming Medical University, Kunming, China
| | - Eng-Ang Ling
- Department of Anatomy, Young Loo Lin School of Medicine, National University of Singapore, Singapore.
| | - Di Lu
- Technology Transfer Center, Kunming Medical University, Kunming, China.
| |
Collapse
|
2
|
Scutellarin Exerts Anti-Inflammatory Effects in Activated Microglia/Brain Macrophage in Cerebral Ischemia and in Activated BV-2 Microglia Through Regulation of MAPKs Signaling Pathway. Neuromolecular Med 2019; 22:264-277. [DOI: 10.1007/s12017-019-08582-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 11/18/2019] [Indexed: 01/04/2023]
|
3
|
Cheng M, Yang L, Dong Z, Wang M, Sun Y, Liu H, Wang X, Sai N, Huang G, Zhang X. Folic acid deficiency enhanced microglial immune response via the Notch1/nuclear factor kappa B p65 pathway in hippocampus following rat brain I/R injury and BV2 cells. J Cell Mol Med 2019; 23:4795-4807. [PMID: 31087489 PMCID: PMC6584545 DOI: 10.1111/jcmm.14368] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 03/13/2019] [Accepted: 04/14/2019] [Indexed: 12/22/2022] Open
Abstract
Recent studies revealed that folic acid deficiency (FD) increased the likelihood of stroke and aggravated brain injury after focal cerebral ischaemia. The microglia-mediated inflammatory response plays a crucial role in the complicated pathologies that lead to ischaemic brain injury. However, whether FD is involved in the activation of microglia and the neuroinflammation after experimental stroke and the underlying mechanism is still unclear. The aim of the present study was to assess whether FD modulates the Notch1/nuclear factor kappa B (NF-κB) pathway and enhances microglial immune response in a rat middle cerebral artery occlusion-reperfusion (MCAO) model and oxygen-glucose deprivation (OGD)-treated BV-2 cells. Our results exhibited that FD worsened neuronal cell death and exaggerated microglia activation in the hippocampal CA1, CA3 and Dentate gyrus (DG) subregions after cerebral ischaemia/reperfusion. The hippocampal CA1 region was more sensitive to ischaemic injury and FD treatment. The protein expressions of proinflammatory cytokines such as tumour necrosis factor-α, interleukin-1β and interleukin-6 were also augmented by FD treatment in microglial cells of the post-ischaemic hippocampus and in vitro OGD-stressed microglia model. Moreover, FD not only dramatically enhanced the protein expression levels of Notch1 and NF-κB p65 but also promoted the phosphorylation of pIkBα and the nuclear translocation of NF-κB p65. Blocking of Notch1 with N-[N-(3, 5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester partly attenuated the nuclear translocation of NF-κB p65 and the protein expression of neuroinflammatory cytokines in FD-treated hypoxic BV-2 microglia. These results suggested that Notch1/NF-κB p65 pathway-mediated microglial immune response may be a molecular mechanism underlying cerebral ischaemia-reperfusion injury worsened by FD treatment.
Collapse
Affiliation(s)
- Man Cheng
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Liu Yang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Zhiping Dong
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Mengying Wang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Yan Sun
- School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Huan Liu
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Xuan Wang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Na Sai
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Guowei Huang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| | - Xumei Zhang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
| |
Collapse
|
4
|
Yuan Y, Rangarajan P, Kan EM, Wu Y, Wu C, Ling EA. Scutellarin regulates the Notch pathway and affects the migration and morphological transformation of activated microglia in experimentally induced cerebral ischemia in rats and in activated BV-2 microglia. J Neuroinflammation 2015; 12:11. [PMID: 25600517 PMCID: PMC4316603 DOI: 10.1186/s12974-014-0226-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/19/2014] [Indexed: 01/06/2023] Open
Abstract
Background Activated microglial cells release an excess of inflammatory mediators after an ischemic stroke. We reported previously that scutellarin effectively suppressed the inflammatory response induced by activated microglia in rats subjected to middle cerebral artery occlusion (MCAO); however, the mechanism via which scutellarin exerts its effects on microglial activation has not been explored. This study aimed to elucidate if scutellarin can regulate the Notch pathway that is linked to microglia activation in MCAO rat, and in lipopolysaccharide (LPS)-induced BV-2 microglia. Along with this, we also investigated some characteristic behavioral responses of activated microglia. Methods Expression of various members of the Notch pathway, including Notch-1, intracellular Notch receptor domain (NICD), recombining binding protein suppressor of hairless (RBP-JK) and transcription factor hairy and enhancer of split-1 (Hes-1) in activated microglia was assessed by immunofluorescence staining and western blot after experimental MCAO and in vitro LPS activation. The effect of scutellarin on migration of microglia was determined by the transwell chamber assay as well as expression of monocyte chemoattractant protein-1 (MCP-1). The morphological change of microglia induced by scutellarin was detected by F-actin staining and electron microscopy. Results Scutellarin markedly attenuated the expression of NF-κB, Notch-1, NICD, RBP-JK and Hes-1 both in vivo and in activated microglia. It decreased the expression of MCP-1 and microglial migration, but increased the ability of microglia adhesion. Scutellarin also altered the phenotype of microglia by causing rearrangement or reorganization of its cytoskeleton. Conclusions The results suggest that scutellarin regulates the activation of microglia via the Notch pathway and concurrently induces morphological and functional changes in activated microglia. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0226-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Yun Yuan
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, PR China.
| | - Parakalan Rangarajan
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore.
| | - Enci Mary Kan
- Defense Medical and Environmental Research Institute, DSO National Laboratories, 27 Medical Drive, Singapore, 117510, Singapore.
| | - Yajun Wu
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore.
| | - Chunyun Wu
- Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, PR China.
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore.
| |
Collapse
|
5
|
Wang JY, Darbinyan A, White MK, Darbinian N, Reiss K, Amini S. Involvement of IRS-1 interaction with ADAM10 in the regulation of neurite extension. J Cell Physiol 2014; 229:1039-46. [PMID: 24648009 DOI: 10.1002/jcp.24528] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/04/2013] [Indexed: 11/09/2022]
Abstract
The insulin-like growth factor-1 (IGF-1) signaling pathway plays an important role in neuronal cell differentiation. Recent studies have shown that IGF-1 has the capacity to counteract the retraction of neuronal processes in response to inflammatory cytokines such as TNF-α, which is a known factor for neuronal injury in the central nervous system. This event is thought to be mediated via interference of TNF-α-induced interaction of β1-integrin with insulin receptor substrate-1 (IRS-1). Here, we demonstrate the interaction of IRS-1 with disintegrin and metalloproteinase ADAM10 through the N-terminal domain of IRS-1 and that this is involved in the regulation of neurite extension and retraction by IGF-1 and TNF-α, respectively. PC12 cells expressing the N-terminal domain show enhanced neurite extension after IGF-1 treatment and reduced neurite depletion relative to control cells after TNF-α treatment. The level of ADAM10 was found to be increased in immunohistochemical studies of HIV encephalitis clinical samples and is present with TNF-α and TNFR1 in both astrocytes and neurons. Altogether, these observations suggest a role for ADAM10 in the mechanism for IGF1/IRS-1 signaling pathway in sustaining the stability of neuronal processes.
Collapse
Affiliation(s)
- Jin Ying Wang
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | | | | | | | | | | |
Collapse
|
6
|
Czarnowski A, Papp S, Szaraz P, Opas M. Calreticulin affects cell adhesiveness through differential phosphorylation of insulin receptor substrate-1. Cell Mol Biol Lett 2014; 19:77-97. [PMID: 24470116 PMCID: PMC6275655 DOI: 10.2478/s11658-014-0181-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/20/2014] [Indexed: 11/21/2022] Open
Abstract
Cellular adhesion to the underlying substratum is regulated through numerous signaling pathways. It has been suggested that insulin receptor substrate 1 (IRS-1) is involved in some of these pathways, via association with and activation of transmembrane integrins. Calreticulin, as an important endoplasmic reticulum-resident, calcium-binding protein with a chaperone function, plays an obvious role in proteomic expression. Our previous work showed that calreticulin mediates cell adhesion not only by affecting protein expression but also by affecting the state of regulatory protein phosphorylation, such as that of c-src. Here, we demonstrate that calreticulin affects the abundance of IRS-1 such that the absence of calreticulin is paralleled by a decrease in IRS-1 levels and the unregulated overexpression of calreticulin is accompanied by an increase in IRS-1 levels. These changes in the abundance of calreticulin and IRS-1 are accompanied by changes in cell-substratum adhesiveness and phosphorylation, such that increases in the expression of calreticulin and IRS-1 are paralleled by an increase in focal contact-based cell-substratum adhesiveness, and a decrease in the expression of these proteins brings about a decrease in cell-substratum adhesiveness. Wild type and calreticulin-null mouse embryonic fibroblasts (MEFs) were cultured and the IRS-1 isoform profile was assessed. Differences in morphology and motility were also quantified. While no substantial differences in the speed of locomotion were found, the directionality of cell movement was greatly promoted by the presence of calreticulin. Calreticulin expression was also found to have a dramatic effect on the phosphorylation state of serine 636 of IRS-1, such that phosphorylation of IRS-1 on serine 636 increased radically in the absence of calreticulin. Most importantly, treatment of cells with the RhoA/ROCK inhibitor, Y-27632, which among its many effects also inhibited serine 636 phosphorylation of IRS-1, had profound effects on cell-substratum adhesion, in that it suppressed focal contacts, induced extensive close contacts, and increased the strength of adhesion. The latter effect, while counterintuitive, can be explained by the close contacts comprising labile bonds but in large numbers. In addition, the lability of bonds in close contacts would permit fast locomotion. An interesting and novel finding is that Y-27632 treatment of MEFs releases them from contact inhibition of locomotion, as evidenced by the invasion of a cell's underside by the thin lamellae and filopodia of a cell in close apposition.
Collapse
Affiliation(s)
- Arthur Czarnowski
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario Canada M5S 1A8
| | - Sylvia Papp
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario Canada M5S 1A8
| | - Peter Szaraz
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario Canada M5S 1A8
| | - Michal Opas
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario Canada M5S 1A8
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King’s College Circle, Medical Sciences Building, room 6326, Toronto, Ontario M5S 1A8 Canada
| |
Collapse
|
7
|
Applications of snake venom components to modulate integrin activities in cell-matrix interactions. Int J Biochem Cell Biol 2013; 45:1974-86. [PMID: 23811033 DOI: 10.1016/j.biocel.2013.06.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/29/2013] [Accepted: 06/12/2013] [Indexed: 01/23/2023]
Abstract
Snake venom proteins are broadly investigated in the different areas of life science. Direct interaction of these compounds with cells may involve a variety of mechanisms that result in diverse cellular responses leading to the activation or blocking of physiological functions of the cell. In this review, the snake venom components interacting with integrins will be characterized in context of their effect on cellular response. Currently, two major families of snake venom proteins are considered as integrin-binding molecules. The most attention has been devoted to the disintegrin family, which binds certain types of integrins through specific motifs recognized as a tri-peptide structurally localized on an integrin-binding loop. Other snake venom integrin-binding proteins belong to the C-type lectin family. Snake venom molecules bind to the cellular integrins resulting in a modulation of cell signaling and in consequence, the regulation of cell proliferation, migration and apoptosis. Therefore, snake venom research on the integrin-binding molecules may have significance in biomedicine and basic cell biology.
Collapse
|
8
|
Abstract
The family of insulin receptor substrates (IRS) consists of four proteins (IRS-1-IRS-4), which were initially characterized as typical cytosolic adaptor proteins involved in insulin receptor (IR) and insulin-like growth factor I receptor (IGF-IR) signaling. The first cloned and characterized member of the IRS family, IRS-1, has a predicted molecular weight of 132 kDa, however, as a result of its extensive serine phosphorylation it separates on a SDS gel as a band of approximately 160-185 kDa. In addition to its metabolic and growth-promoting functions, IRS-1 is also suspected to play a role in malignant transformation. The mechanism by which IRS-1 supports tumor growth is not fully understood, and the argument that IRS-1 merely amplifies the signal from the IGF-1R and/or IR requires further investigation. Almost a decade ago, we reported the presence of nuclear IRS-1 in medulloblastoma clinical samples, which express viral oncoprotein, large T-antigen of human polyomavirus JC (JCV T-antigen). This first demonstration of nuclear IRS-1 was confirmed by several other laboratories. Nuclear IRS-1 was also detected by cells expressing the SV40 T-antigen, v-Src, in immortalized fibroblasts stimulated with IGF-I, in hepatocytes, 32D cells, and in an osteosarcoma cell line. More recently, nuclear IRS-1 was detected in breast cancer cells in association with estrogen receptor alpha (ERα), and in JC virus negative medulloblastoma cells expressing estrogen receptor beta (ERβ), further implicating nuclear IRS-1 in cellular transformation. Here, we discuss how nuclear IRS-1 acting on DNA repair fidelity, transcriptional activity, and cell growth can support tumor development and progression.
Collapse
Affiliation(s)
- Krzysztof Reiss
- Neurological Cancer Research, Stanley S. Scott Cancer Center, School of Medicine, LSU Health Sciences Center, New Orleans, LA 70112, USA.
| | | | | | | |
Collapse
|
9
|
Walsh EM, Marcinkiewicz C. Non-RGD-containing snake venom disintegrins, functional and structural relations. Toxicon 2011; 58:355-62. [PMID: 21801741 DOI: 10.1016/j.toxicon.2011.07.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 05/25/2011] [Accepted: 07/12/2011] [Indexed: 01/16/2023]
Abstract
Snake venom disintegrins are present in a variety of species and are functionally divided into three families: RGD, MLD and R/KTS. The RGD family of disintegrins, which bind and inhibit the physiological functions of RGD-dependent integrins, constitute the largest and most investigated family. This review will be focused on characterization of two relatively new families of snake venom disintegrins, expressing in their active site MLD and R/KTS motifs. The MLD motif, present only in heterodimeric disintegrins, mediates binding of these disintegrins to α4β1, α4β7 and α9β1 integrins, whereas the presence of a KTS or RTS sequence in the active site selectively directs activity of disintegrins to the collagen receptor α1β1 integrin. Structurally, KTS-disintegrins are short, monomeric molecules containing 41 amino acids in its polypeptide chain. Biological activities of MLD and KTS-disintegrins were investigated in many systems in vitro and in vivo. Purified disintegrins are non-toxic in therapeutic doses in rodent and avian models. Their modulatory properties were observed in investigations of cancer angiogenesis and metastasis, immunosuppression of IDDM (insulin-dependent diabetes mellitus) and asthma, as well as in neurodegenerative assays and cell apoptosis.
Collapse
Affiliation(s)
- Erin M Walsh
- Temple University, College of Science and Technology, Department of Biology, Philadelphia, PA 19122, United States
| | | |
Collapse
|
10
|
Central insulin resistance and synaptic dysfunction in intracerebroventricular-streptozotocin injected rodents. Neurobiol Aging 2011; 33:430.e5-18. [PMID: 21256630 DOI: 10.1016/j.neurobiolaging.2010.12.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 11/22/2010] [Accepted: 12/07/2010] [Indexed: 11/24/2022]
Abstract
To better understand the role of insulin signaling in the development of Alzheimer's disease (AD), we utilized an animal model (intracerebroventricular injection of streptozotocin-ic-streptozotocin (STZ)) that displays insulin resistance only in the brain and exhibits AD pathology. In this model, deficits in hippocampal synaptic transmission and long-term potentiation (LTP) were observed. The decline in LTP correlated with decreased expression of NMDAR subunits NR2A and NR2B. The deficits in LTP were accompanied by changes in the expression and function of synaptic AMPARs. In ic-STZ animals, an alteration in integrin-linked kinase (ILK)-glycogen synthase kinase 3 beta (GSK-3-β) signaling was identified (p < 0.05). Similarly, there was decreased expression (p < 0.05) of brain derived neurotropic factor (BDNF) and stargazin, an AMPAR auxiliary subunit; both are required for driving AMPA receptors to the surface of the postsynaptic membrane. Our data illustrate that altered ILK-GSK-3β signaling due to impaired insulin signaling may decrease the trafficking and function of postsynaptic glutamate receptors; thereby, leading to synaptic deficits contributing to memory loss.
Collapse
|
11
|
Wilk A, Urbanska K, Yang S, Wang JY, Amini S, Del Valle L, Peruzzi F, Meggs L, Reiss K. Insulin-like growth factor-I-forkhead box O transcription factor 3a counteracts high glucose/tumor necrosis factor-α-mediated neuronal damage: implications for human immunodeficiency virus encephalitis. J Neurosci Res 2010; 89:183-98. [PMID: 21162126 DOI: 10.1002/jnr.22542] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/29/2010] [Accepted: 10/04/2010] [Indexed: 12/17/2022]
Abstract
In HIV patients, antiretroviral medications trigger metabolic abnormalities, including insulin resistance. In addition, the inflammatory cytokine tumor necrosis factor-α (TNFα), which is elevated in human immunodeficiency virus encephalitis (HIVE), also induces insulin resistance and inflicts neuronal damage in vitro. In differentiated PC12 cells and rat cortical neurons, high glucose (HG; 25 mM) triggers reactive oxygen species (ROS) accumulation, contributing to the retraction of neuronal processes, with only a minimal involvement of neuronal apoptosis. In the presence of TNFα, HG-treated neurons undergo massive apoptosis. Because mammalian homolog of the Forkhead family of transcription factors, Forkhead box O transcription factor 3a (FOXO3a), controls ROS metabolism, we asked whether FOXO3a could affect the fate of differentiated neurons in the paradigm of HIVE. We observed FOXO3a nuclear translocation in HG-treated neuronal cultures, accompanied by partial loss of mitochondrial potential and gradual retraction of neuronal processes. Addition of TNFα to HG-treated neurons increased expression of the FOXO-dependent proapoptotic gene Bim, which resulted in extensive apoptotic death. Insulin-like growth factor-I (IGF-I) significantly lowered intracellular ROS, which was accompanied by IGF-I-mediated FOXO3a nuclear export and decrease in its transcriptional activity. The clinical relevance of these findings is supported by detection of nuclear FOXO3a in TUNEL-positive cortical neurons from HIVE, especially in brain areas characterized by elevated TNFα.
Collapse
Affiliation(s)
- Anna Wilk
- Neurological Cancer Research, Stanley S. Scott Cancer Center, LSU Health Sciences Center, New Orleans, Louisianna 70112, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Canonici A, Steelant W, Rigot V, Khomitch-Baud A, Boutaghou-Cherid H, Bruyneel E, Van Roy F, Garrouste F, Pommier G, André F. Insulin-like growth factor-I receptor, E-cadherin and alpha v integrin form a dynamic complex under the control of alpha-catenin. Int J Cancer 2008; 122:572-82. [PMID: 17955485 DOI: 10.1002/ijc.23164] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dynamic crosstalk between cell adhesion molecules, extracellular matrix and soluble informative factors is essential for cancer cell migration and invasion. Here, we investigated the mechanisms by which the E-cadherin/catenin complex and alpha v integrin can modulate insulin-like growth factor-I (IGF-I)-induced cell migration. Human colon mucosa, human colon cancer cell lines, HT29-D4 and HCT-8 derivatives that differ in their expression of alpha-catenin, were used as models. Interactions between E-cadherin, alpha v integrin and IGF-I receptor (IGF-IR) were analyzed by coimmunoprecipitation and immunolocalization experiments. The impact of these interactions on cell mobility was determined by haptotaxis assays. We report that alpha v integrin, E-cadherin and IGF-IR form a ternary complex in both cultured cancer cells and human normal colonic mucosa. alpha-Catenin regulates the scaffolding of this complex. IGF-IR ligation by IGF-I induces the disruption of the complex and the relocalization of alpha v integrin from cell-cell contacts to focal contact sites. This perturbation is correlated with the observed increase in cell migration. These results suggest that regulation of the alpha v integrin/E-cadherin/IGF-IR scaffolding is essential for the modulation of cell mobility. Its alteration could be of major importance to sustain alterations in cell adhesion that occur during cancer cell invasion and metastasis.
Collapse
Affiliation(s)
- Alexandra Canonici
- CISMET, FRE CNRS 2737, Universités d'Aix-Marseille I et II, Marseille, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|