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Redigolo L, Sanfilippo V, La Mendola D, Forte G, Satriano C. Bioinspired Nanoplatforms Based on Graphene Oxide and Neurotrophin-Mimicking Peptides. MEMBRANES 2023; 13:membranes13050489. [PMID: 37233550 DOI: 10.3390/membranes13050489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/22/2023] [Accepted: 04/26/2023] [Indexed: 05/27/2023]
Abstract
Neurotrophins (NTs), which are crucial for the functioning of the nervous system, are also known to regulate vascularization. Graphene-based materials may drive neural growth and differentiation, and, thus, have great potential in regenerative medicine. In this work, we scrutinized the nano-biointerface between the cell membrane and hybrids made of neurotrophin-mimicking peptides and graphene oxide (GO) assemblies (pep-GO), to exploit their potential in theranostics (i.e., therapy and imaging/diagnostics) for targeting neurodegenerative diseases (ND) as well as angiogenesis. The pep-GO systems were assembled via spontaneous physisorption onto GO nanosheets of the peptide sequences BDNF(1-12), NT3(1-13), and NGF(1-14), mimicking the brain-derived neurotrophic factor (BDNF), the neurotrophin 3 (NT3), and the nerve growth factor (NGF), respectively. The interaction of pep-GO nanoplatforms at the biointerface with artificial cell membranes was scrutinized both in 3D and 2D by utilizing model phospholipids self-assembled as small unilamellar vesicles (SUVs) or planar-supported lipid bilayers (SLBs), respectively. The experimental studies were paralleled via molecular dynamics (MD) computational analyses. Proof-of-work in vitro cellular experiments with undifferentiated neuroblastoma (SH-SY5Y), neuron-like, differentiated neuroblastoma (dSH-SY5Y), and human umbilical vein endothelial cells (HUVECs) were carried out to shed light on the capability of the pep-GO nanoplatforms to stimulate the neurite outgrowth as well as tubulogenesis and cell migration.
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Affiliation(s)
- Luigi Redigolo
- Nano Hybrid Biointerfaces Lab (NHBIL), Department of Chemical Sciences, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
| | - Vanessa Sanfilippo
- Nano Hybrid Biointerfaces Lab (NHBIL), Department of Chemical Sciences, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
| | - Diego La Mendola
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, 56126 Pisa, Italy
| | - Giuseppe Forte
- Department of Drug and Health Science, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
| | - Cristina Satriano
- Nano Hybrid Biointerfaces Lab (NHBIL), Department of Chemical Sciences, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
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Emery AC, Liu XH, Xu W, Eiden MV, Eiden LE. Cyclic Adenosine 3',5'-Monophosphate Elevation and Biological Signaling through a Secretin Family Gs-Coupled G Protein-Coupled Receptor Are Restricted to a Single Adenylate Cyclase Isoform. Mol Pharmacol 2015; 87:928-35. [PMID: 25769305 DOI: 10.1124/mol.115.098087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/12/2015] [Indexed: 12/11/2022] Open
Abstract
PC12 cells express five adenylate cyclase (AC) isoforms, most abundantly AC6 and AC7. These two ACs were individually silenced using lentiviral short hairpin RNAs, which lead to a decrease (≥80%) of the protein product of each transcript. These stable PC12 sublines were then used to examine potential AC isoform preference for signaling through a family B G protein-coupled receptor (GPCR). Cells were challenged with the endogenous agonist of the pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1), pituitary adenylate cyclase-activating polypeptide (PACAP)-38, or the diterpene forskolin as an AC-proximal control. Intracellular cAMP levels were elevated by forskolin about equally in wild-type, AC6, and AC7 knockdown cells. The ability of PACAP-38 and forskolin to activate three cAMP sensors downstream of AC [protein kinase A (PKA), exchange protein activated by cAMP (Epac) 2/Rapgef4, and neuritogenic cAMP sensor (NCS)/Rapgef2] was examined by monitoring the phosphorylation status of their respective targets, cAMP response element-binding protein, p38, and extracellular signal-regulated kinase. Forskolin stimulation of each downstream target of cAMP was unaffected by knockdown of either AC6 or AC7. PACAP-38 activation of all downstream targets of cAMP was unaffected by AC7 knockdown, but abolished following AC6 knockdown. Membrane cholesterol depletion with methyl-β-cyclodextrin mimicked the effects of AC6 silencing on PACAP signaling, without attenuating forskolin signaling. These data suggest that vicinal constraint of the GPCR PAC1 and AC6 determines the exclusive requirement for this AC in PACAP signaling, but that the coupling of the cAMP sensors PKA, Epac2/Rapgef4, and NCS/Rapgef2, to their respective downstream signaling targets, determines how cAMP signaling is parcellated to physiologic responses, such as neuritogenesis, upon GPCR-Gs activation in neuroendocrine cells.
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Affiliation(s)
- Andrew C Emery
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Xiu-Huai Liu
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Wenqin Xu
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Maribeth V Eiden
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
| | - Lee E Eiden
- Sections on Molecular Neuroscience (A.C.E., X.-H.L., L.E.E.) and Directed Gene Transfer (W.X., M.V.E.), Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, Bethesda, Maryland
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Yu R, Cui Z, Li M, Yang Y, Zhong J. Dimer-dependent intrinsic/basal activity of the class B G protein-coupled receptor PAC1 promotes cellular anti-apoptotic activity through Wnt/β-catenin pathways that are associated with dimer endocytosis. PLoS One 2014; 9:e113913. [PMID: 25426938 PMCID: PMC4245242 DOI: 10.1371/journal.pone.0113913] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 11/02/2014] [Indexed: 12/23/2022] Open
Abstract
The high expression of PACAP (pituitary adenylate cyclase-activating polypeptide)-preferring receptor PAC1 is associated with nerve injury and tumors. Our previous report (Yu R, et al. PLoS One 2012; 7: e51811) confirmed the dimerization of PAC1 and found that the M-PAC1 mutation in the N-terminal first Cys/Ala lost the ability to form dimers. In this study, Chinese hamster ovary (CHO-K1) cells overexpressing wild-type PAC1 (PAC1-CHO) had significantly higher anti-apoptotic activities against serum withdrawal-induced apoptosis associated with a lower caspase 3 activity and a higher Bcl-2 level in a ligand-independent manner than those of CHO cells overexpressing the mutant M-PAC1 (M-PAC1-CHO). PAC1-CHO had significantly higher β-catenin, cyclin D1 and c-myc levels corresponding to the Wnt/β-catenin signal than did M-PAC1-CHO. In addition, the Wnt/β-catenin pathway inhibitor XAV939 significantly inhibited the anti-apoptotic activities of PAC1-CHO. Top-flash assays demonstrated that PAC1-CHO had a significantly stronger Wnt/β-catenin signal than did M-PAC1-CHO. Acetylcysteine (NAC) as an inhibitor of the dimerization of PAC1 inhibited the anti-apoptotic activities that were endowed by PAC1 and decreased the Wnt/β-catenin signal in Top-flash assays. In the PAC1 Tet (tetracycline)-on inducible gene expression system by doxycycline (Dox), higher expression levels of PAC1 resulted in higher anti-apoptotic activities that were associated with a stronger Wnt/β-catenin signal. A similar correlation was also found with the down-regulation of PAC1 in the Neuro2a neuroblastoma cell. BiFC combined with fluorescence confocal imaging indicated that during serum-withdrawal-induced apoptosis, PAC1 dimers displayed significant endocytosis. These findings indicate that PAC1 has ligand-independent and dimer-dependent intrinsic/basal activity, conferring cells with anti-apoptotic activities against serum withdrawal, which is involved in the Wnt/β-catenin signal and is associated with the endocytosis of PAC1 dimers. The discovery and study of the dimer-dependent basal activity of PAC1 not only help us understand the physiological and pathological role of PAC1 but also promote the development of drugs targeting PAC1.
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Affiliation(s)
- Rongjie Yu
- Institute of Biomedicine, Department of Cell Biology, Jinan University, Guangzhou, China
- * E-mail:
| | - Zekai Cui
- Institute of Biomedicine, Department of Cell Biology, Jinan University, Guangzhou, China
| | - Mei Li
- Institute of Biomedicine, Department of Cell Biology, Jinan University, Guangzhou, China
| | - Yanxu Yang
- Institute of Biomedicine, Department of Cell Biology, Jinan University, Guangzhou, China
| | - Jiaping Zhong
- Institute of Biomedicine, Department of Cell Biology, Jinan University, Guangzhou, China
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Mahavadi S, Bhattacharya S, Kim J, Fayed S, Al-Shboul O, Grider JR, Murthy KS. Caveolae-dependent internalization and homologous desensitization of VIP/PACAP receptor, VPAC₂, in gastrointestinal smooth muscle. Peptides 2013; 43:137-45. [PMID: 23499767 PMCID: PMC4026926 DOI: 10.1016/j.peptides.2013.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 12/18/2022]
Abstract
The main membrane proteins of caveolae (caveolin-1, -2 and -3) oligomerize within lipid rich domains to form regular invaginations of smooth muscle plasma membrane and participate in receptor internalization and desensitization independent of clathrin-coated vesicle endocytosis. We have previously shown that Gs-coupled VIP/PACAP receptors, VPAC2, predominantly expressed in smooth muscle cells of the gut, are exclusively phosphorylated by GRK2 leading to receptor internalization and desensitization. Herein, we characterized the role of caveolin-1 in VPAC2 receptor internalization and desensitization in gastric smooth muscle using three approaches: (i) methyl β-cyclodextrin (MβCD) to deplete cholesterol and disrupt caveolae in dispersed muscle cells, (ii) caveolin-1 siRNA to suppress caveolin-1 expression in cultured muscle cells, and (iii) caveolin-1 knockout mice (caveolin-1(-/-)). Pretreatment of gastric muscle cells with VIP stimulated tyrosine phosphorylation of caveolin-1, and induced VPAC2 receptor internalization (measured as decrease in (125)I-VIP binding after pretreatment) and desensitization (measured as decrease in VIP-induced cAMP formation after pretreatment). Caveolin-1 phosphorylation, and VPAC2 receptor internalization and desensitization were blocked by disruption of caveolae with MβCD, suppression of caveolin-1 with caveolin-1 siRNA or inhibition of Src kinase activity by PP2. Pretreatment with VIP significantly inhibited adenylyl cyclase activity and muscle relaxation in response to subsequent addition of VIP in freshly dispersed muscle cells and in muscle strips isolated from wild type and caveolin-1(-/-) mice; however, the inhibition was significantly attenuated in caveolin-1(-/-) mice. These results suggest that caveolin-1 plays an important role in VPAC2 receptor internalization and desensitization.
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Affiliation(s)
| | | | | | | | | | | | - Karnam S. Murthy
- Corresponding author at: Department of Physiology, Virginia Commonwealth University, Richmond, VA 23298-0551, United States. Tel.: +1 804 828 0029; fax: +1 804 827 0947. (K.S. Murthy)
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Ge X, Qiu Y, Loh HH, Law PY. GRIN1 regulates micro-opioid receptor activities by tethering the receptor and G protein in the lipid raft. J Biol Chem 2009; 284:36521-36534. [PMID: 19861419 DOI: 10.1074/jbc.m109.024109] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The lipid raft location of mu-opioid receptor (MOR) determines the receptor activities. However, the manner in which MOR is anchored within the lipid rafts is undetermined. Using the targeted proteomic approach and mass spectrometry analyses, we have identified GRIN1 (G protein-regulated inducer of neurite outgrowth 1) can tether MOR with the G protein alpha-subunit and subsequently regulate the receptor distribution within the lipid rafts. Glutathione S-transferase fusion pulldown and receptor mutational analyses indicate that GRIN1-MOR interaction involves a receptor sequence (267)GSKEK(271) within the MOR third intracellular loop that is not involved in Galpha interaction. The GRIN1 domains involved in MOR interaction are also distinct from those involved in Galpha interaction. Pertussis toxin pretreatment reduced the amount of GRIN1 co-immunoprecipitated with MOR but not the amount with Galpha. Furthermore, overexpression of GRIN1 significantly enhanced the amount of MOR in lipid raft and the receptor signaling magnitude as measured by Src kinase activation. Such increase in MOR signaling was demonstrated further by determining the GRIN1-dependent pertussis toxin-sensitive neurite outgrowth. In contrast to minimal neurite outgrowth induced by etorphine in control neuroblastoma N2A cells, overexpression of GRIN1 resulted in the increase in etorphine- and non-morphine-induced neurite outgrowth in these cells. Knocking down endogenous GRIN1 by small interfering RNA attenuated the agonist-induced neurite outgrowth. Disrupting lipid raft by methyl-beta-cyclodextrin also blocked neurite outgrowth. Hence, by tethering Galpha with MOR, GRIN1 stabilizes the receptor within the lipid rafts and potentiates the receptor signaling in the neurite outgrowth processes.
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Affiliation(s)
- Xin Ge
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455.
| | - Yu Qiu
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Horace H Loh
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455
| | - Ping-Yee Law
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455
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Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BKC, Hashimoto H, Galas L, Vaudry H. Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery. Pharmacol Rev 2009; 61:283-357. [DOI: 10.1124/pr.109.001370] [Citation(s) in RCA: 829] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Fasano C, Niel JP. The mammalian sympathetic prevertebral ganglia: Models for the study of neuronal networks and basic neuronal properties. Auton Neurosci 2009; 150:8-20. [DOI: 10.1016/j.autneu.2009.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 06/04/2009] [Accepted: 06/05/2009] [Indexed: 11/24/2022]
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Draghetti C, Salvat C, Zanoguera F, Curchod ML, Vignaud C, Peixoto H, Di Cara A, Fischer D, Dhanabal M, Andreas G, Abderrahim H, Rommel C, Camps M. Functional whole-genome analysis identifies Polo-like kinase 2 and poliovirus receptor as essential for neuronal differentiation upstream of the negative regulator alphaB-crystallin. J Biol Chem 2009; 284:32053-65. [PMID: 19700763 DOI: 10.1074/jbc.m109.009324] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This study aimed at identifying transcriptional changes associated to neuronal differentiation induced by six distinct stimuli using whole-genome microarray hybridization analysis. Bioinformatics analyses revealed the clustering of these six stimuli into two categories, suggesting separate gene/pathway dependence. Treatment with specific inhibitors demonstrated the requirement of both Janus kinase and microtubule-associated protein kinase activation to trigger differentiation with nerve growth factor (NGF) and dibutyryl cAMP. Conversely, activation of protein kinase A, phosphatidylinositol-3-kinase alpha, and mammalian target of rapamycin, although required for dibutyryl cAMP-induced differentiation, exerted a negative feedback on NGF-induced differentiation. We identified Polo-like kinase 2 (Plk2) and poliovirus receptor (PVR) as indispensable for NGF-driven neuronal differentiation and alphaB-crystallin (Cryab) as an inhibitor of this process. Silencing of Plk2 or PVR blocked NGF-triggered differentiation and Cryab down-regulation, while silencing of Cryab enhanced NGF-induced differentiation. Our results position both Plk2 and PVR upstream of the negative regulator Cryab in the pathway(s) leading to neuronal differentiation triggered by NGF.
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Affiliation(s)
- Cristina Draghetti
- Departments of Target Research, Merck Serono International S.A. 9, Chemin de Mines, 1202 Geneva, Switzerland
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Zhang W, Smith A, Liu JP, Cheung NS, Zhou S, Liu K, Li QT, Duan W. GSK3β modulates PACAP-induced neuritogenesis in PC12 cells by acting downstream of Rap1 in a caveolae-dependent manner. Cell Signal 2009; 21:237-45. [DOI: 10.1016/j.cellsig.2008.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Revised: 10/15/2008] [Accepted: 10/15/2008] [Indexed: 10/21/2022]
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Matsuzaki S, Tohyama M. Regulation of pituitary adenylyl cyclase-activating polypeptide (PACAP, ADCYAP1: adenylyl cyclase-activating polypeptide 1) in the treatment of schizophrenia. Expert Opin Ther Targets 2008; 12:1097-108. [PMID: 18694377 DOI: 10.1517/14728222.12.9.1097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Deficiency of pituitary adenylyl cyclase-activating polypeptide (PACAP) and its specific receptor, PAC1, causes a schizophrenia-like phenotype in mice. In addition, the relation of the PACAP and PAC1 genes to schizophrenia has been shown by single-nucleotide polymorphism association studies. Furthermore, PACAP is reported to be involved in the function of disrupted-in-schizophrenia 1. OBJECTIVE To summarize briefly the recent evidence relating the PACAP system and schizophrenia and discuss the application of PACAP to the treatment of schizophrenia. RESULTS/CONCLUSION The regulation of PACAPergic signals is an interesting potential treatment for schizophrenia. Further studies of PACAP signals and the association of PACAP signals with schizophrenia should shed the light on the utility of this approach in the treatment of schizophrenia.
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Affiliation(s)
- Shinsuke Matsuzaki
- Osaka University, The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Graduate School of Medicine, Department of Anatomy and Neuroscience, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Roychowdhury S, Rasenick MM. Submembraneous microtubule cytoskeleton: regulation of microtubule assembly by heterotrimeric Gproteins. FEBS J 2008; 275:4654-63. [PMID: 18754776 PMCID: PMC2782913 DOI: 10.1111/j.1742-4658.2008.06614.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heterotrimeric Gproteins participate in signal transduction by transferring signals from cell surface receptors to intracellular effector molecules. Gproteins also interact with microtubules and participate in microtubule-dependent centrosome/chromosome movement during cell division, as well as neuronal differentiation. In recent years, significant progress has been made in our understanding of the biochemical/functional interactions between Gprotein subunits (alpha and betagamma) and microtubules, and the molecular details emerging from these studies suggest that alpha and betagamma subunits of Gproteins interact with tubulin/microtubules to regulate the assembly/dynamics of microtubules, providing a novel mechanism for hormone- or neurotransmitter-induced rapid remodeling of cytoskeleton, regulation of the mitotic spindle for centrosome/chromosome movements in cell division, and neuronal differentiation in which structural plasticity mediated by microtubules is important for appropriate synaptic connections and signal transmission.
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Affiliation(s)
- Sukla Roychowdhury
- Department of Biological Sciences, University of Texas, El Paso, TX, USA.
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Kilian P, Campbell S, Bilodeau L, Guimond MO, Roberge C, Gallo-Payet N, Payet MD. Angiotensin II type 2 receptor stimulation increases the rate of NG108-15 cell migration via actin depolymerization. Endocrinology 2008; 149:2923-33. [PMID: 18326001 DOI: 10.1210/en.2007-0313] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Angiotensin II (Ang II) has been reported to induce migration in neuronal cell types. Using time-lapse microscopy, we show here that Ang II induces acceleration in NG108-15 cell migration. This effect was antagonized by PD123319, a selective AT2 receptor antagonist, but not by DUP753, a selective AT1 receptor antagonist, and was mimicked by the specific AT2 receptor agonist CGP42112. This Ang II-induced acceleration was not sensitive to the inhibition of previously described signaling pathways of the AT2 receptor, guanylyl cyclase/cyclic GMP or p42/p44 mapk cascades, but was abolished by pertussis toxin treatment and involved PP2A activation. Immunofluorescence studies indicate that Ang II or CGP42112 decreased the amount of filamentous actin at the leading edge of the cells. This decrease was accompanied by a concomitant increase in globular actin levels. Regulation of actin turnover in actin-based motile systems is known to be mainly under the control of the actin depolymerizing factor and cofilin. Basal migration speed decreased by 77.2% in cofilin-1 small interfering RNA-transfected NG108-15 cells, along with suppression of the effect of Ang II. In addition, the Ang II-induced increase in cell velocity was abrogated in serum-free medium as well as by genistein or okadaic acid treatment in a serum-containing medium. Such results indicate that the AT2 receptor increases the migration speed of NG108-15 cells and involves a tyrosine kinase activity, followed by phosphatase activation, which may be of the PP2A type. Therefore, the present study identifies actin depolymerization and cofilin as new targets of AT2 receptor action, in the context of cellular migration.
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Affiliation(s)
- Peter Kilian
- Département de Physiologie et Biophysique, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke 3001, 12 Avenue Nord, Sherbrooke, Québec, Canada J1H 5N4
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Pool M, Thiemann J, Bar-Or A, Fournier AE. NeuriteTracer: a novel ImageJ plugin for automated quantification of neurite outgrowth. J Neurosci Methods 2007; 168:134-9. [PMID: 17936365 DOI: 10.1016/j.jneumeth.2007.08.029] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 08/10/2007] [Accepted: 08/30/2007] [Indexed: 01/06/2023]
Abstract
In vitro assays to measure neuronal growth are a fundamental tool used by many neurobiologists studying neuronal development and regeneration. The quantification of these assays requires accurate measurements of neurite length and neuronal cell numbers in neuronal cultures. Generally, these measurements are obtained through labor-intensive manual or semi-manual tracing of images. To automate these measurements, we have written NeuriteTracer, a neurite tracing plugin for the freely available image-processing program ImageJ. The plugin analyzes fluorescence microscopy images of neurites and nuclei of dissociated cultured neurons. Given user-defined thresholds, the plugin counts neuronal nuclei, and traces and measures neurite length. We find that NeuriteTracer accurately measures neurite outgrowth from cerebellar, DRG and hippocampal neurons. Values obtained by NeuriteTracer correlate strongly with those obtained by semi-manual tracing with NeuronJ and by using a sophisticated analysis package, MetaXpress. We reveal the utility of NeuriteTracer by demonstrating its ability to detect the neurite outgrowth promoting capacity of the rho kinase inhibitor Y-27632. Our plugin is an attractive alternative to existing tracing tools because it is fully automated and ready for use within a freely accessible imaging program.
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Affiliation(s)
- Madeline Pool
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, BT-109, 3801 Rue University, Montreal, Quebec, Canada H3A 2B4
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