Deferoxamine-induced neurite outgrowth and synapse formation
in postnatal rat dorsal root ganglion (DRG) cell cultures
Marcin Nowickia, Joanna Kosackaa, Katharina Spanel-Borowskia and Jürgen Borlakb, ,
aUniversity of Leipzig, Institute of Anatomy, Liebigstraße 13, D-04103 Leipzig, Germany
bFraunhofer Institute of Toxicology and Experimental Medicine, Nikolai-Fuchs-Straße 1, D-30625 Hannover, Germany
Received 11 March 2009; revised 22 May 2009; accepted 25 May 2009. Available online 5 July 2009.

Abstract
Deferoxamine (DFO) was granted orphan drug status for the
treatment of traumatic spinal cord injury but its
neuroprotective mechanism is not well understood.
We therefore investigated the mode of action of DFO in
serum-starved and/or iron-stressed cultures of rat dorsal
root ganglion (DRG) cells.
We probed for redox signaling by determining hemeoxygenase-1
activity and by measuring expression of intracellular iron
metabolism-related proteins under pro-oxidative conditions.
We also employed DNA microarrays to better understand the
genomic response of DRG cultures to treatment with DFO thereby
enabling the generation of hypotheses.
Essentially, DFO treatment resulted in outgrowth of
neurofilament 200-positive neurites and induction of synapse
formation as determined by immunoblotting, transmission
electron microscopy and immunofluorescence confocal microscopy.
Furthermore, DFO treatment of DRG cell cultures activated
neuroprotective and antioxidative programs such as matrix
metallopeptidase 2 and apolipoprotein D to promote neurite
regeneration.
Indeed, DFO reduced markedly reactive oxygen species formation,
increased the expression of hemeoxygenase-1 and improved iron
management through regulation of transferrin receptor and ferritin.
We propose DFO treatment of DRG cell cultures to completely
abolish the oxidative effect of ferrous iron (Fe2+).
Taken collectively, DFO reduced oxidative stress and induced
synthesis of neuroprotective and antioxidative molecules to foster
nerve repair and functional recovery.
Our findings help to better understand the therapeutic benefit
of DFO in the treatment of spinal cord injury.

“Iron is only toxic when elevated inside cells.”
“Only neurons and oligodendrocytes were injured by this elevation”
“Erythropoietin promotes regeneration of adult central nervous system
neurons”

Those three phrases coincidentally coincide with a well known
treatment.

Iron reduction therapy.

Iron injures neurons and oligodendrocytes.
Erythropoietin promotes regeneration of neurons.
Iron LOWERS erythropoietin production.
Iron reduction therapy INCREASES erythropoietin production.

J Neurosci 2002 Jul 15;22(14):5848-55

The Relationship between Intracellular Free Iron and Cell Injury in
Cultured
Neurons, Astrocytes, and Oligodendrocytes.

Kress GJ, Dineley KE, Reynolds IJ
Department of Pharmacology, University of Pittsburgh, Pittsburgh,
Pennsylvania
15261.

Iron is an essential element for cells but may also be an important
cytotoxin.
However, very little is known about iron transport, redox status, or
toxicity specifically inside cells.
In this study, we exploited the sensitivity of fura-2 to quenching by
ferrous iron (Fe(2+)) to detect intracellular free iron ([Fe(2+)](i))
in neurons, astrocytes, and oligodendrocytes in primary culture.
All cell types exposed to Fe(2+) in the presence of the ionophore
pyrithione rapidly accumulated Fe(2+) to a similar extent.
The heavy-metal chelators bipyridyl and N,N,N’,N’-tetrakis(2-
pyridalmethyl)ethyl-enediamine rapidly reversed the increase in
[Fe(2+)](i), whereas desferrioxamine had little effect.
Interestingly, the Fe(2+)-mediated quenching of fura-2 fluorescence
was reversed in a concentration-dependent manner by hydrogen
peroxide.
This was likely caused by the oxidation of Fe(2+) to Fe(3+) inside the
cell.
Acute exposure of cells to Fe(2+) was only toxic when the metal was
applied together with pyrithione, showing that Fe(2+) is only toxic
when elevated inside cells.
Interestingly, only neurons and oligodendrocytes were injured by this
elevation in [Fe(2+)](i), whereas astrocytes were unaffected, although
[Fe(2+)](i) was elevated to the same degree in each cell type.
These studies provide a novel approach for detecting [Fe(2+)](i) in a
manner sensitive to the redox state of the metal.
These studies also provide a model system for the study of the toxic
consequences of elevated [Fe(2+)](i) in neural cells.

PMID: 12122047, UI: 22117891

“Erythropoietin promotes regeneration of adult central nervous system
neurons”

HEPATOLOGY
Erythropoietin promotes hepatic regeneration after extended liver
resection in rats
Maximilian Schmeding,* Sabine Boas-Knoop,* Steffen Lippert,* Martin
Ruehl, † Radjan Somasundaram, † Tarkan Dagdelen, † Peter Neuhaus* and
Ulf P Neumann*
*Department of General, Visceral and Transplantation Surgery at
Charité, Campus Virchow Klinikum, Universitaetsmedizin Berlin, and
†
Department of Gastroenterology and Hepatology, Charité, Campus
Benjamin Franklin, Universitaetsmedizin, Berlin, Germany
Correspondence to Dr Maximilian Schmeding, Department of General,
Visceral and Transplantation Surgery, Charité, Campus Virchow
Klinikum, Universitaetsmedizin Berlin, Augustenburger Platz 1, 13353
Berlin, Germany. Email: maximilian.schmed…@charite.de
Copyright Journal compilation © 2008 Blackwell Publishing Asia Pty
Ltd
and Journal of Gastroenterology and Hepatology Foundation
KEYWORDS
erythropoietin (EPO) • hepatic regeneration • liver resection
ABSTRACT
Background and Aim: It has been proven in various animal studies that
recombinant human erythropoietin (rHuEPO) protects renal, cardiac and
neuronal, as well as hepatic, tissue from ischemia, and promotes
regeneration of adult central nervous system neurons. To date, no
data
are available as to whether rHuEPO has the ability to stimulate liver
regeneration after liver resection.

Methods: Rats undergoing 70% or 90% hepatectomy received an
intraportalvenous administration (i.p.) of rHuEPO prior to resection
or a subcutaneous injection (s.c.) for 3 days postoperatively,
control
animals were treated with surgery and saline injection only.
Regeneration capacity of remnant livers was studied over 7 days by
histology and immunohistochemistry (Ki-67, proliferating cell nuclear
antigen [PCNA]). Polymerase chain reaction was carried out to measure
transforming growth factor β (TGF-β), hypoxia induced factor (HIF),
signal transducing activator 3 and vascular endothelial growth
factor.

Results: Ten-day survival in rats undergoing 90% hepatectomy
significantly increased in i.p.-pretreated animals. After 70%
hepatectomy the mitotic index was significantly increased in both
rHuEPO-treated groups. These data were confirmed by PCNA and Ki-67
expression, which was significantly increased in the treated groups
24
h and 2 days after liver resection. TGF-β and HIF mRNA both were
upregulated in control animals 3 h after surgery.

Conclusion: rHuEPO effectively increased liver regeneration in rats
after 70% liver resection and enhanced survival after 90%
hepatectomy.
Thus, rHuEPO may increase the regenerative capacity after major
hepatectomy.

Accepted for publication 16 October 2007.

DIGITAL OBJECT IDENTIFIER (DOI)
10.1111/j.1440-1746.2007.05265.x About DOI