antidepressants modulate human hippocampal neurogenesis by
TRANSCRIPT
Antidepressants increase adult hippocampal neurogenesis and promote
neuronal differentiation in rodents, but the underlying molecular mechanisms
are unknown.
Here we treated human embryonic hippocampal progenitor cells with the
antidepressant, sertraline, and investigated changes in cell proliferation and
neuronal differentiation. We find that antidepressants increase neuronal
differentiation and decrease cell proliferation by activating the glucocorticoid
receptor (GR), and by increasing GR-mediated gene transcription of the cell
cycle inhibitors p27Kip1 and p57Kip2.
� Chronic stress and depression are associated with elevated levels of
glucocorticoid hormones and with decreased hippocampal neurogenesis. (Gould et al.,1992; David et al., 2009; Boldrini et al., 2009).
� Antidepressants increase adult hippocampal neurogenesis, and thereby
possibly contribute to the resolution of some of the behavioural deficits in
depression (Santarelli et al., 2003; David et al., 2009).
� Glucocorticoids and antidepressants both activate the glucocorticoid
receptor (GR). The GR is a nuclear transcription factor, and GR–
transactivation (GR binding to DNA) induces transcription of the cyclin-
dependent kinase 2 (CDK2)-inhibitors p27Kip1 and p57Kip2, which have been
implicated in early neuronal development (Pariante et al., 1997; Shin et al., 2009; Ye et
al., 2009).
Antidepressants modulate human hippocampal neurogenesis by
activating the glucocorticoid receptorChristoph Anacker, Patricia A. Zunszain, Annamaria Cattaneo, Livia A. Carvalho, Sandrine Thuret, Jack Price, Carmine M. Pariante
Centre for the Cellular Basis of Behaviour, Institute of Psychiatry, King’s College London, United Kingdom
email.: [email protected]
BACKGROUND
ABSTRACT
• Adult neurogenesis & Depression
MAP2+,
NeuN+,
tuj1+
Dcx+, PSA-
NCAM+
� Antidepressants enhance neuronal
differentiation of hippocampal
progenitor cells (Wang et al., 2008)
� Antidepressants increase progenitor
cell proliferation in depressed
patients or in mice which are co-
treated with glucocorticoids (Boldrini et al., 2009; David et al., 2009).
HYPOTHESIS
� Antidepressants enhance neuronal differentiation, but increase progenitor
cell proliferation only in the presence of glucocorticoids
� The effect of antidepressants on neurogenesis is dependent on the
glucocorticoid receptor (GR)
� GR-dependent expression of the CDK2-inhibtiors p27Kip1 and p57Kip2 mediates
the effect of antidepressants on proliferation and neuronal differentiation
RESULTS
• Antidepressants modulate hippocampal progenitor cell
proliferation by activating the GR
Figure 1. BrdU immunocytochemistry (a). Sertraline (SERT 1uM, red bars) and the
glucocorticoid dexamethasone (DEX 1uM, black bars) decrease cell proliferation. Only DEX
and SERT co-treatment increases cell proliferation (green bars). These effects are abolished
by the GR-antagonist RU486 (50nM) (b). *p<0.05, **p<0.01, n=5
a.
-30
-20
-10
0
10
20
RU486 (50nM) + + +__
SERT 1uM
DEX 1uM
DEX 1uM +SERT 1uM
*_**
***
**
Brd
U+
cells
(%
ch
ang
e fr
om
veh
)
b.
• Antidepressants induce GR transactivation and decrease GR expression
Figure 2. Sertraline induces GR-transactivation (a) and decreases GR mRNA (b) and
protein (c) after 12h of cell proliferation. *p<0.05, **p<0.01, ***p0.001; n=3
a. b. c.
GRtotal
ACTB
veh DEX SERT D+S
Dcx & MAP2
Immunostaining
&
Cell counting
BrdU
Immunostaining
GR-DNA
binding assay
Quantitative
Real-time PCR
Western Blot
METHODS
• Proliferation assay
• Differentiation assay
7 days Differentiation
1.
2.
3.
3 days Proliferation
Treatment
TreatmentTreatment
4hrs
BrdU
Treatment
(DEX, antidepressants, DEX & antidepressants)
3days Proliferation
� Human embryonic hippocampal progenitor cell line HPC03A/07 (ReNeuron, UK)
CONCLUSIONS
• Antidepressants enhance neuronal differentiation and promote
neuronal maturation by activating the GR
Hoechst Dcx Hoechst MAP2
Figure 3. Sertraline induces differentiation into Dcx+ cells (1) and promotes neuronal
maturation into MAP2+ cells (2). This effect is absent if sertraline is not present during the
proliferation phase (3). *p<0.05, **p<0.01, ***p0.001; n=5
� Sertraline decreases progenitor cell proliferation via a GR-dependent effect;
cell proliferation is only increased in the presence of glucocorticoids (Fig 1)
� Sertraline induces GR transactivation, decreases GR expression, and increases
the CDK2-inhibitors p27Kip1 and p57Kip2 during cell proliferation (Fig 2)
� Sertraline increases neuronal differentiation and maturation via a GR-
dependent effect, but only if already present during the proliferation phase
(Fig 3)
ACKNOWLEDGEMENTS
This project was funded by the European Union Framework7, the Medical Research Council UK and an NIHR BRC studentship in Biomedical and Mental Health to C. Anacker.
• Antidepressants induce expression of p27Kip1 and p57Kip2
2.
3.
1.
Treatment
Lie et al. 2004
BrdUHoechst
RU486 (50nM)
+
0.0
0.5
1.0
1.5
2.0
2.5SERT 1uM
veh
fold
cha
nge
from
con
trol
0.0
0.5
1.0
1.5
2.0
2.5
*
fold
cha
nge
from
con
trol
*
p57Kip2
expression
6h 12h 24h 48h 72h0.0
0.5
1.5
2.0
2.5SERT 1uM
DEX 1uM
DEX 1uM +SERT 1uM
*
fold
cha
nge
from
con
trol
p57Kip2
expressionp27Kip1
expression
6h 12h 24h 48h 72h
0.0
0.5
1.5
2.0
2.5SERT 1uM
DEX 1uM
DEX 1uM+SERT 1uM*
fold
ch
ang
e f
rom
co
ntr
ol
p27Kip1
expression
RU486 (50nM)
SERT 1uM
veh
***
***
GR proteinGR mRNA
6h 12h 24h 48h 72h
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
SERT 1uMDEX 1uMDEX 1uM+SERT 1uM
**fold
cha
nge
VEH DEX SERT D+S
0.00
0.25
0.50
0.75
1.00 Dex 1uMSERT 1uMDex+SERT
fold
indu
ctio
n
1h 6h 12h 24h 72h
-30
-20
-10
0
10
20
30
GR transactivation
*SERT 1uM
% c
hang
e in
GR
-DN
A b
indi
ng
__ +__
-45
-35
-25
-15
-5
5
15
25
* SERTDEX
+
Dcx+ neuroblasts
SERT+DEX
_***+_+_RU486 (50nM)
Dcx
+ ce
lls (
% c
han
ge)
-45
-35
-25
-15
-5
5
15
25
RU486 (50nM) + +__ +
MAP2+ neurons
_
SERTDEXSERT+DEX
**
Dcx
+ ce
lls (
% c
han
ge)
Dcx+ neuroblasts
-30
-20
-10
0
10
RU486 (50nM) + +_ _ +*** _
SERTDEXSERT+DEX
Dcx
+ c
ells
(%
cha
nge)
MAP2+ neurons
-50
-25
0
25
50
RU486 (50nM) + +_ _ +
**
**
SERTDEXSERT+DEX
_
MA
P2+
cel
ls (
% c
hang
e)
-45
-35
-25
-15
-5
5
15
25SERT
SERT+ DEX
Dcx+ neuroblasts
DEX
Dcx
+ ce
lls (
% c
han
ge)
-45
-35
-25
-15
-5
5
15
25SERT
SERT+ DEX
MAP2+ neurons
DEX
MA
P2+
cel
ls (
% c
han
ge)
CONFLICT OF INTEREST
J. Price acts as a consultant for ReNeuron Group