Epidermal growth factor and basic fibroblast growth factor: effects on an overlapping population of neocortical neurons in vitro - ScienceDirect

Brain Research

Volume 535, Issue 2, 10 December 1990, Pages 255-263

Brain Research

https://doi.org/10.1016/0006-8993(90)91608-J Get rights and content

Abstract

Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) have trophic effects on rat neocortical neurons in vitro. Concentration-response studies reveal that EGF maximally stimulates neuronal survival and process outgrowth at approximately 10 ng/ml, while the maximal effect of bFGF is seen at 10–30 ng/ml. Treatment with maximal concentrations of bFGF results in cultures containing a greater number of neurons with long processes, as well as greater branching of processes, than does treatment with EGF. When EGF and bFGF are added together to cultures the effects are not additive. In addition, bFGF is capable of supporting the survival of neurons previously treated with EGF. These findings indicate that EGF and bFGF affect a largely overlapping population of neocortical neurons, but that bFGF may be a more effective trophic agent for these cells.

Reference (29)

BairdA. et al.
Molecular characterization of fibroblast growth factor: distribution and biological activities in various tissues
Recent Prog. Horm. Res.
(1986)
BergeyG.K. et al.
Neuronal maturation in mammalian cell culture is dependent on spontaneous electrical activity
Brain Research
(1981)
FerrariG. et al.
Basic fibroblast growth factor promotes the survival and development of mesencephalic neurons in culture
Dev. Biol.
(1989)
GospodarowiczD. et al.
Fibroblast growth factor
Mol. Cell. Endocrinol.
(1986)
GrotheC. et al.
Basic fibroblast growth factor promotes in vitro survival and cholinergic development of rat septal neurons: comparison with the effects of nerve growth factor
Neuroscience
(1989)
HattenM.E. et al.
In vitro neurite extension by granule neurons is dependent upon astroglial-derived fibroblast growth factor
Develop. Biol.
(1988)
HerkenhamM.
Mismatches between neurotransmitter and receptor localizations in brain: observations and implications
Neuroscience
(1987)
SavageC.R. et al.
Epidermal growth factor and a new derivative
J. Biol. Chem.
(1972)
SchaudiesR.P. et al.
Epidermal growth factor immunoreactive material in rat brain
J. Biol. Chem.
(1989)
ThomasK.A. et al.
Fibroblast growth factors: broad spectrum mitogens with potent angiogenic activity
Trends Biochem. Sci.
(1986)

WalickeP. et al.

Neurotrophic effects of basic and acidic fibroblast growth factors are not mediated through glial cells

Develop. Brain Res.

(1988)

AhmedZ. et al.

Properties of neurons from dissociated fetal rat brain in serum-free culture

J. Neurosci.

(1983)

AndersonK.J. et al.

Basic fibroblast growth factor prevents the death of lesioned cholinergic neurons in vitro

Nature

(1988)

CarpenterG.J. et al.

Epidermal growth factor

Ann. Rev. Biochem.

(1979)

Cited by (73)

Serum epidermal growth factor, clinical illness course, and limbic brain volumes in early-stage bipolar disorder
2020, Journal of Affective Disorders
Citation Excerpt :
Animal models show that peripheral EGF is transported across the blood-brain barrier in a saturable, likely receptor-mediated process (Pan and Kastin, 1999). Administration of EGF prolongs the lifespans of cortical neurons in vitro and dopaminergic neurons in vivo (Kornblum et al., 1990; Ventrella, 1993). Mice deficient in EGFRs experience hippocampal neuronal disorganization and cortical and thalamic neurodegeneration (Sibilia et al., 1998).
Epidermal growth factor (EGF) belongs to a family of growth factors implicated in the etiology of psychiatric illnesses. We conducted this cross-sectional case-control study to determine whether (1) serum EGF levels differ between bipolar disorder (BD) patients and non-BD comparison subjects, (2) EGF levels in patients are influenced by mood illness related factors (number of past mood episodes, medication treatment) and non-mood illness related factors (body mass index), and (3) lower EGF levels predict lower limbic brain volumes in BD.
We measured serum EGF in 51 early-stage BD patients and 22 healthy comparison subjects (HS). A subset of 25 patients underwent cerebral magnetic resonance imaging (MRI). Participants were assessed at the University of British Columbia Mood Disorders Centre between June 2004 and June 2012.
A general linear model with diagnosis and BMI category (overweight/obese vs normal weight) as factors showed that patients had lower mean log(e)-transformed EGF (LnEGF) than HS (4.99 vs 5.47, p = .011). There was no effect of BMI and no diagnosis x BMI interaction. Multiple linear regression models showed that in patients, more past mood episodes predicted lower LnEGF (β = −0.358, t = −2.585, p = .013) and lower LnEGF predicted lower bilateral temporal lobe volumes (left: β = 0.560, p = .011; right: β = 0.543, p = .009).
Our cross-sectional study design limits our ability to make inferences about the causal directions of the relationships between EGF, diagnosis, mood episodes, and brain volumes.
These findings provide preliminary evidence that EGF is a novel biomarker that may play a role in the pathophysiology of BD.
Controlled release of dextrin-conjugated growth factors to support growth and differentiation of neural stem cells
2018, Stem Cell Research
Citation Excerpt :
Based on these results, it is envisaged that the use of dextrin-conjugated growth factors could significantly improve the efficiency of not only stem cell maintenance and expansion (reducing the necessity for growth factor supplementation by up to 7-fold), but also could be employed clinically at inflamed sites. It is well known that EGF and bFGF are essential for the proliferation and expansion of neural stem cells (Gritti et al., 1996; Kornblum et al., 1990; Morrison et al., 1988; Morrison et al., 1987; Kojima and Tator, 2002). Recent studies have shown that sustained growth factor levels decrease spontaneous differentiation and increase proliferation, yet this is not achieved in routine stem cell maintenance, even with daily culture medium replacement (Lotz et al., 2013).
An essential aspect of stem cell in vitro culture and in vivo therapy is achieving sustained levels of growth factors to support stem cell survival and expansion, while maintaining their multipotency and differentiation potential. This study investigated the ability of dextrin (~74,000 g/mol; 27.8 mol% succinoylation) conjugated to epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF; or FGF-2) (3.9 and 6.7% w/w protein loading, respectively) to support the expansion and differentiation of stem cells in vitro via sustained, controllable growth factor release. Supplementation of mouse neural stem cells (mNSCs) with dextrin-growth factor conjugates led to greater and prolonged proliferation compared to unbound EGF/bFGF controls, with no detectable apoptosis after 7 days of treatment. Immunocytochemical detection of neural precursor (nestin) and differentiation (Olig2, MAP2, GFAP) markers verified that controlled release of dextrin-conjugated growth factors preserves stem cell properties of mNSCs for up to 7 days. These results show the potential of dextrin-growth factor conjugates for localized delivery of bioactive therapeutic agents to support stem cell expansion and differentiation, and as an adjunct to direct neuronal repair.
EGFR signaling upregulates surface expression of the GluN2B-containing NMDA receptor and contributes to long-term potentiation in the hippocampus
2015, Neuroscience
Citation Excerpt :
To confirm that the immunofluorescence signals do actually represent endogenous EGFRs, we treated DIV14 cultured hippocampal neurons with recombinant EGF for 15 min and observed the changes in EGFR staining pattern. In responsive neurons (Kornblum et al., 1990), a significant increase in EGFR clusters (cluster count per 100-μm dendrite; before EGF treatment, 9.44 ± 1.63, n = 33; after EGF treatment, 32.94 ± 2.13, n = 34; P < 0.0001) was observed in dendrites upon EGF treatment (Fig. 2A), while the density of PSD95 (cluster count per 100-μm dendrite; before EGF treatment, 60.19 ± 3.06, n = 18; after EGF treatment, 58.67 ± 3.42, n = 20; P > 0.05) and gephyrin (cluster count per 100-μm dendrite; before EGF treatment, 25.52 ± 2.42, n = 15; after EGF treatment, 29.37 ± 3.48, n = 14; P > 0.05) clusters were unchanged (Fig. 2D). EGFR has been shown to dimerize with other members of the EGFR family such as ErbB4 (Riese et al., 1996; Yarden and Sliwkowski, 2001).
N-methyl-d-aspartate receptors (NMDARs) have been known to be regulated by various receptor tyrosine kinases. Activation of epidermal growth factor receptor (EGFR) specifically increases NMDAR-mediated currents and enhances long-term potentiation (LTP) in the hippocampus. However, the mechanism through which EGFR regulates NMDARs remains to be elucidated. In this study we found that EGFR was highly expressed in the hippocampus and mainly localized in the non-synaptic region including the soma and neurites of cultured hippocampal neurons. EGFR activation led to an increase in ifenprodil-sensitive NMDAR currents. Consistent with this, we also observed that surface expression of GluN2B-containing NMDAR was upregulated. Our biochemical data from hippocampal slices and hippocampal cultured neurons demonstrated that EGF treatment in vitro significantly increased phosphorylation of the GluN2B subunit at Y1472 with a coincidental activation of Src family kinases (SFKs). EGFR blockade with a specific antagonist BIBX-1382 attenuated an increase of GluN2B in the postsynaptic density during high-frequency stimulation (HFS)-induced LTP. Moreover, BIBX blockade significantly impaired HFS-induced LTP. In conclusion, our findings suggest that EGFR signaling upregulates NMDARs through modification of the GluN2B subunit, and is required for HFS-induced LTP in the hippocampus.
Loss of function genetic screens reveal MTGR1 as an intracellular repressor of β1 integrin-dependent neurite outgrowth
2009, Journal of Neuroscience Methods
Integrins are transmembrane receptors that promote neurite growth and guidance. To identify regulators of integrin-dependent neurite outgrowth, here we used two loss of function genetic screens in SH-SY5Y neuroblastoma cells. First, we screened a genome-wide retroviral library of genetic suppressor elements (GSEs). Among the many genes identified in the GSE screen, we isolated the hematopoetic transcriptional factor MTGR1 (myeloid translocation gene-related protein-1). Treatment of SH-SY5Y cells with MTGR1 siRNA enhanced neurite outgrowth and concurrently increased expression of GAP-43, a protein linked to neurite outgrowth. Second, we transduced SH-SY5Y with a genome-wide GFP-labeled lentiviral siRNA library, which expressed 40,000 independent siRNAs targeting 8500 human genes. From this screen we isolated GFI1 (growth factor independence-1), which, like MTGR1, is a member of the myeloid translocation gene on 8q22 (MTG8)/ETO protein complex of nuclear repressor proteins. These results reveal novel contributions of MTGR1 and GFI1 to the regulation of neurite outgrowth and identify novel repressors of integrin-dependent neurite outgrowth.
PC12 cell activation by epidermal growth factor receptor: Role of autophosphorylation sites
2003, International Journal of Developmental Neuroscience
Citation Excerpt :
EGF can act as a neurotrophic factor towards postmitotic neurons of the CNS (Morrison, 1993; Plata-Salamán, 1991). Furthermore, EGF can induce neuronal processes and enhance survival of cultured rat cerebellar cortical neurons (Kornblum et al., 1990; Morrison et al., 1988). PC12 cells have been used extensively to study the neurotrophic actions of NGF and FGF.
PC12 cells have been used as a model system for neuronal differentiation due to their ability to alter their phenotype to a sympathetic neuron-like cell in response to nerve growth factor or fibroblast growth factor. Under some conditions, epidermal growth factor (EGF) can also induce PC12 cells to differentiate. To study signaling from the EGF receptor without the confounding effects of endogenous EGF receptors we generated a chimeric receptor comprised of the ectodomain of platelet-derived growth factor (PDGF) receptor in-frame with the transmembrane and cytoplasmic domains of EGF receptor, termed PER. Expression of PER in PC12 cells confers the ability of PDGF to induce differentiation whereas PDGF has no effect on untransfected PC12 cells. This response is kinase activity-dependent since a kinase-deficient mutant (K721M) fails to induce differentiation in response to PDGF. Mutation of five tyrosine residues that are autophosphorylated in response to EGF either individually or in combination had minimal effects on the ability of these receptors to induce morphological PC12 cell differentiation. The PER mutant with all five autophosphorylation sites mutated to phenylalanine (5YF) was equivalently capable of interacting with several important signaling molecules, including Shc, Grb2, Gab1, phospholipase Cγ, and Cbl. Furthermore, both the phosphatidylinositol 3-kinase (PI3K)/Akt and Ras/Erk pathways were activated in a sustained manner when PER or 5YF-expressing cells were stimulated with PDGF. Our results show that the five autophosphorylation sites in the extra-kinase C-terminal domain of EGFR are not required for the ability of EGFR to induce morphological differentiation of PC12 cells.
What role(s) for TGFα in the central nervous system?
2000, Progress in Neurobiology
Transforming growth factor α (TGFα) is a member of the epidermal growth factor (EGF) family with which it shares the same receptor, the EGF receptor (EGFR or erbB1). Identified since 1985 in the central nervous system (CNS), its functions in this organ have started to be determined during the past decade although numerous questions remain unanswered. TGFα is widely distributed in the nervous system, both glial and neuronal cells contributing to its synthesis. Although astrocytes appear as its main targets, mediating in part TGFα effects on different neuronal populations, results from different studies have raised the possibility for a direct action of this growth factor on neurons. A large array of experimental data have thus pointed to TGFα as a multifunctional factor in the CNS. This review is an attempt to present, in a comprehensive manner, the very diverse works performed in vitro and in vivo which have provided evidences for (i) an intervention of TGFα in the control of developmental events such as neural progenitors proliferation/cell fate choice, neuronal survival/differentiation, and neuronal control of female puberty onset, (ii) its role as a potent regulator of astroglial metabolism including astrocytic reactivity, (iii) its neuroprotective potential, and (iv) its participation to neuropathological processes as exemplified by astroglial neoplasia. In addition, informations regarding the complex modes of TGFα action at the molecular level are provided, and its place within the large EGF family is precised with regard to the potential interactions and substitutions which may take place between TGFα and its kindred.

View all citing articles on Scopus

⁺: Present address: Cortex Pharmaceuticals, Irvine, CA 92718, U.S.A.

^*: Present address: H.I. Kornblum. Present address: Department of Pediatrics, UCLA Medical Center, 10833 Le Conte Avenue, Los Angeles, CA 90024, U.S.A.

Copyright © 1990 Published by Elsevier B.V.