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The Journal of Neuroscience, April 1, 1998, 18(7):2570-2580
Distinct Ontogeny of Glucocorticoid and Mineralocorticoid
Receptor and 11 -Hydroxysteroid Dehydrogenase Types I and II mRNAs in
the Fetal Rat Brain Suggest a Complex Control of Glucocorticoid
Actions
Rochellys
Diaz,
Roger W.
Brown, and
Jonathan R.
Seckl
Molecular Medicine Centre, Western General Hospital, University of
Edinburgh, Edinburgh EH4 2XU, United Kingdom
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ABSTRACT |
Glucocorticoids (GCs) act via intracellular mineralocorticoid (MR)
and glucocorticoid receptors (GR). However, it has recently been
recognized that GC access to receptors is determined by the presence of
tissue-specific 11 -hydroxysteroid dehydrogenases (11 -HSDs) that
catalyze the interconversion of active corticosterone and inert
11-dehydrocorticosterone. 11 -HSD type 1 (11 -HSD1) is a
bidirectional enzyme in vitro that acts predominantly as a reductase (regenerating corticosterone) in intact neurons. In contrast, 11 -HSD type 2 (11 -HSD2) is a higher affinity exclusive dehydrogenase that excludes GCs from MR in the kidney, producing aldosterone-selectivity in vivo. We have examined the
ontogeny of 11 -HSD mRNAs and enzyme activity during prenatal brain
development and correlated this with GR and MR mRNA development. These
data reveal that (1) 11 -HSD2 mRNA is highly expressed in all CNS
regions during midgestation, but expression is dramatically reduced
during the third trimester except in the thalamus and cerebellum; (2) 11 -HSD2-like activity parallels closely the pattern of mRNA
expression; (3) 11 -HSD1 mRNA is absent from the CNS until the the
third trimester, and activity is low or undectectable; and (4) GR mRNA
is highly expressed throughout the brain from midgestation, but MR gene expression is absent until the last few days of gestation. High 11 -HSD2 at midgestation may protect the developing brain from activation of GR by GCs. Late in gestation, repression of 11 -HSD2 gene expression may allow increasing GC activation of GR and MR, permitting key GC-dependent neuronal and glial maturational events.
Key words:
11 -hydroxysteroid dehydrogenases; glucocorticoid
receptor; mineralocorticoid receptor; ontogeny; fetal brain; rats
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INTRODUCTION |
A wealth of studies suggest that
early life environment influences brain development and subsequent
adult CNS function. In particular, maternal stress during pregnancy
produces persisting neuroendocrine and behavioral abnormalities in the
offspring, altering motor development, enhancing emotionality,
amplifying amphetamine self-administration, and increasing locomotor
responses to novelty (Ader and Blackman, 1971 ; Barlow et al., 1978 ;
Demeniere et al., 1992 ). Prenatal stress also modifies the offspring
hypothalamic-pituitary-adrenal (HPA) axis, a key neuroendocrine
effector of the stress response (Meaney et al., 1996 ; Weinstock et al.,
1997 ). Clinically, HPA axis dysregulation is associated with
psychiatric syndromes including depression, eating disorders, anxiety,
and age-related cognitive dysfunction (Holsboer et al., 1994 ; Seckl and
Olsson, 1995 ), and neurodevelopmental factors may be etiologically
important in several of these syndromes. Indeed, HPA axis activity in
elderly men correlates with birth weight, which is a measure of the
prenatal environment (Phillips et al., 1997 ). Together, these data
suggest that maternal stress during pregnancy could increase the
vulnerability of the offspring to behavioral brain-related pathologies.
These changes could be mediated by in utero exposure of the
developing brain to elevated levels of maternal glucocorticoids (GCs)
secreted during HPA axis activation by stress that can cross the
placenta barrier and reach the developing fetal brain (Zarrow et al.,
1970 ). Prenatal GC exposure permanently "programs" several central
functions, including dopamine sensitivity (Diaz et al., 1997 ),
serotonergic activity (Slotkin et al., 1996 ), and HPA axis parameters
(Levitt et al., 1996 ).
GC actions are primarily mediated via intracellular glucocorticoid
receptor (GR) and mineralocorticoid receptor (MR) (de Kloet, 1991 ). MRs
bind both physiological GCs (cortisol, corticosterone) and
mineralocorticoids (aldosterone) with an equally high affinity (Kd, 0.5 nM), whereas GR
preferentially binds cortcosterone but with a lower affinity (2.5-5.0
nM). However, it has recently been recognized that the
effects of GCs on their target cells are not only regulated by plasma
steroid levels, corticosteroid-binding globulin (CBG), and receptor
density, but also by the presence of 11 -hydroxysteroid
dehydrogenases (11 -HSDs) (Seckl, 1997a ). 11 -HSDs catalyze the
interconversion of physiological GCs (cortisol and corticosterone) and
inert 11-keto metabolites (cortisone and 11-dehydrocorticosterone).
Recently two isozymes have been characterized, encoded by distinct
genes (White et al., 1997 ). 11 -HSD type 1 (11 -HSD1) is a widely
expressed NADPH-dependent oxidoreductase (Agarwal et al., 1989 ). In
intact cells, including neurons, 11 -HSD1 is a predominant
11 -reductase that regenerates active corticosterone from inert
11-dehydrocorticosterone (Hundertmark et al., 1995 ; Jamieson et al.,
1995 ; Rajan et al., 1996 ). In contrast, 11 -HSD type 2 (11 -HSD2)
is a nicotinamide adenine dinucleotide (NAD)-dependent high-affinity
isozyme and is an exclusive 11 -dehydrogenase that rapidly
inactivates GCs, thus protecting otherwise nonselective MR from GCs in
aldosterone target tissues (e.g., distal nephron) (White et al., 1997 ).
Administration of 11 -HSD inhibitors during rat pregnancy adversely
programs peripheral systems, producing hypertension and hyperglycemia
in adult offspring (Lindsay et al., 1996a ,b ). Although 11 -HSD
bioactivity has been previously demonstrated in adult and perinatal
brain (Moisan et al., 1990 ; Lakshmi et al., 1991 ; Moisan et al., 1992 ),
these studies predated the identification of the two isozymes and their
distinct reaction directions. We therefore investigated the detailed
ontogeny of 11 -HSD mRNAs and enzyme activity and correlated this
with GR and MR expression during rat brain prenatal development to
identify potential time- and locus-dependent "windows" for GC
action.
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MATERIALS AND METHODS |
Subjects. Female Sprague Dawley rats were put into
the home cages of individually housed male rats at 5:00 P.M. and were
removed the next morning. Coitus was determined by vaginal smear. The morning of sperm detection was designated embryonic day 0.5 (E0.5). At
least two dams were decapitated at each of successive gestational days
between 11:00 A.M. and 12:00 P.M., and the embryos were removed by
cesarean section. Embryos aged E11.5-E14.5 were immediately frozen
in toto into a 20°C isopentane bath. From E15.5, embryos were decapitated before freezing. All tissues were stored at
80°C.
11 -HSDs and GR and MR probes. The MR cRNA was prepared
from a 513 bp EcoRI fragment of rat mineralocorticoid
receptor cDNA (representing parts of the steroid-binding domain and 3'
untranslated region) and was subcloned into the vector pGEM4 (Arriza et
al., 1988 ). The plasmid was linearized with either HindIII
or EcoRI and used as a template for SP6 or T7 RNA polymerase
to generate the antisense and sense, respectively. The GR cRNA was
prepared from a 674 bp PstI-EcoRI fragment of
the rat glucocorticoid receptor cDNA corresponding to the 3' portion of
the coding region (steroid-binding domain) and was subcloned into the
vector pGEM3 (Seckl et al., 1990 ). The antisense and sense probes were
generated using AvaI (T7) and EcoRI (SP6),
respectively. The 11 -HSD2 was prepared from a 613 bp fragment
obtained by reverse transcription-PCR from rat kidney RNA using primers
to conserved regions of the 11 -HSD2 and subcloned into a pGEM-T
vector (Leckie et al., 1995 ). The antisense and sense probes were
generated using NcoI (SP6) and NotI (T7),
respectively. The 11 -HSD1 was prepared from a 1.2 kb
EcoRI fragment of the rat 11 -HSD1 cDNA and subcloned into the vector pBluescript SKII (Agarwal et al., 1989 ). The antisense and
sense probes were generated using StyI (T3) and
PstI (T7), respectively. 35S-Uridine
5'-triphospate (UTP)-labeled RNA antisense and sense probes were
transcribed in vitro using the appropriate template and
phage RNA polymerase, purified using Nensorb Columns (DuPont, Billerica, MA), and checked on denaturing acrylamide gels.
In situ hybridization. Sagittal (in relation to the
head) 20 µm cryostat sections were thaw-mounted on
3-aminopropyltriethoxysilane-coated slides and stored at 80°C.
Tissue sections were fixed, prehybridized, hybridized (hybridization
was made with ~3 × 106 cpm/section
35S-UTP-labeled RNA probe at 50°C for 12-14 hr), and
washed essentially as described previously (Belluardo et al., 1997 ).
After RNase A washing, treated slides were hydrated, dried, placed
against -Max (Hyperfilm -film; Amersham, Arlington Heights, IL),
and stored at room temperature for 1-2 weeks. Films were developed in
D19 developer for 2 min and fixed in a 1:5 dilution of Amfix fixative
for 2 min. Adjacent sections were stained with cresyl violet to allow
neuroanatomical localization of the specifically labeled CNS regions
(data not shown). The atlas of prenatal rat brain development by Altman
and Bayer (1995) was consulted. Nonspecific hybridization was
determined by incubating adjacent sections with the respective
35S-UTP-labeled sense cRNA probe for the above cDNAs under
identical conditions. Nonspecific background was very low in all
sections analyzed from all fetal ages (data not shown).
11 -HSD activity. 11 -Reductase and 11 -dehydrogenase
activity was determined from homogenates of rat brain tissue at ages E12.5, E14.5, E17.5, and E20.5. The assays were performed according to
a standard protocol described elsewhere (Brown et al., 1996 ) and
included 100 µM cofactor (NAD or NADP for dehydrogenase
or NADPH for reductase) and 12 nM final
3H-labeled steroid ([3H]corticosterone
for dehydrogenase and [3H]11-dehydrocorticosterone
for reductase). In addition, we assayed samples of liver (for
reductase) and placenta (for dehydrogenase) from each fetus as an
internal control to demonstrate that 11 -HSD1 and 11 -HSD2 were
detectable in tissues outside the brain at each gestational age.
Preliminary experiments showed that 0.25 mg/ml homogenate protein was
the optimal concentration in the curve describing the relationship
between protein concentration and enzyme activity. All assays used 0.25 mg/ml; two time points (10 and 40 min) were used for dehydrogenase and
three time points were used for reductase (10, 40, and 90 min). Because
the results for the dehydrogenase were similar at the two time points,
only the 10 min data are presented.
Corticoterone levels. Plasma corticosterone levels were
measured by radioimmunoassay at ages E12.5, E14.5, E17.5, and E20.5, as
described previously (Holmes et al., 1997 ), but modified for microtiter
scintillation plate assay (SPA, Amersham). Briefly, the incubation
volume was 120 µl, consisting of 20 µl of 10× diluted plasma,
50 µl of antiserum
(1:10,000)/[3H]corticosterone mix (12,000 cpm/tube
1,2,6,7-[3H]corticosterone, Amersham), and 50 µl
of SPA beads. After an overnight incubation at room temperature, the
microtiter plates were counted on a Wallac microbeta liquid
scintillation counter.
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RESULTS |
Ontogeny of 11 -HSD2 mRNA
High 11 -HSD2 gene expression is observed throughout the CNS
neuroepithelium, including the pituitary gland primordium at E11.5
(Fig. 1) (brain areas are labeled in
Figs.
1-5).
11 -HSD2 mRNA expression remains high until E13.5. By E14.5, the
expression starts to decrease in the neocortex, pallidal area, and
spinal cord (data not shown). By E15.5, 11 -HSD2 expression is
restricted to several discrete areas that include thalamus (although
Fig. 1 only shows anterior and posterior areas, its expression is more widely distributed), cerebellum, midbrain (superior colliculus differentiating field), various pontine regions (e.g., locus coeruleus and precerebellar area), septum, hypothalamus (preoptic area and anterior and ventral hypothalamus), medulla, pallidum (data not shown),
and strianuclear complex. At E16.5, 11 -HSD2 mRNA expression is still
high in several areas that include the straitum, midbrain (superior and
inferior tectal neuroepithelium, inferior colliculus, and pretectum),
thalamus, preoptic area, and ventral hypothalamus (e.g., arcuate
nucleus), cerebellum (external granular layer), and low to moderate in
septum (data not shown) (Fig. 3). 11 -HSD2 mRNA expression remains
similar from E16.5 until E19.5, when expression ceases in the midbrain
and is low in the septum. However, 11 -HSD2 mRNA is still present in
preoptic area and ventral hypothalamus (e.g., arcuate nucleus). By
E20.5, 11 -HSD2 gene expression is restricted to the external
granular layer of the cerebellum, precerebellar area, and thalamus, and
at E22.5 (the day of birth) 11 -HSD2 mRNA is only found in the
external granular layer of the cerebellum and thalamus (Figs. 3,
5).

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Figure 1.
Expression of 11 -HSD type 2 and 11 -HSD type
1 in the rat brain from E11.5 to E15.5. Results of in
situ hybridization for 11 -HSD TYPE 2 and
11 -HSD TYPE 1 are shown from left to
right, respectively, for each gestation. The following
are labeled in Figures 1-5: 1, extraembryonic membrane;
2, hippocampal (Ammon's horn) and subicular regions;
3, neocortex; 4, septum;
5, liver; 6, dorsal mesencephalon;
7, pontine area; 8, intermediate,
mammillary, and posterior hypothalamic areas; 9,
hypothalamus and anterior hypothalamus; 10, tegmental
area; 11, intermediate thalamus; 12, medulla; 13, spinal cord; 14, dorsal
diencephalon; 15, cerebellum; 16,
pituitary; 17, uterine wall; 18, taenia
tecta; 19, indesium griseum; 20,
cingulate cortex; 21, lamina terminalis;
22, epithalamus; 23, pretectum;
24, ventral hypothalamus; 25, preoptic
area; 26, thalamus; 26a, posterior
thalamus and epithalamus; 26b, thalamus and
anterior-medial area; 27, mammillary area;
28, posterior hypothalamus; 29, ventral
isthmal area; 30, inferior colliculus;
31, superior colliculus; 32, dorsal
isthmal area; 33, precerebellar area; 34, basal ganglia and strionuclear area; 35, pallidum;
36, arcuate nucleus and ventral medial hypothalamus;
37, posterior thalamus; 38, anterior
thalamus; 39, olfactory bulb; 40, locus
coerulus; 41, anterior pontine area; 42,
posterior pontine area; 43, dorsal raphe;
44, pineal gland; 45, choroid plexus and
lateral ventricle; 46, skin; 47,
precerebellar area and above choroid plexus; and 48,
dorsal periaqueductal gray and superior colliculus.
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Figure 2.
Expression of GR and MR in the rat brain from
E11.5 to E15.5. Results of in situ hybridization for
GR and MR are shown from left to right, respectively, for each
gestation. For labeling of regions see text of Figure 1.
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Figure 3.
Expression of 11 -HSD type 2 and 11 -HSD type
1 in the rat brain from E16.5 to E20.5. Results of in
situ hybridization for 11 -HSD TYPE 2 and
11 -HSD TYPE 1 are shown from left to
right, respectively, for each gestation. For labeling of
regions see text of Figure 1.
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Figure 4.
Expression of GR and MR in the rat brain from
E16.5 to E20.5. Results of in situ hybridization for
GR and MR are shown from left to right, respectively, for each
gestation. For labeling of regions see text of Figure 1.
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Figure 5.
Expression of GR,
MR, 11 -HSD TYPE 2, and 11 -HSD
TYPE 1 mRNAs in the rat brain at E22.5. For labeling of
regions see text of Figure 1.
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Ontogeny of 11 -HSD1 mRNA
11 -HSD1 mRNA expression is clearly very low or absent before
E15.5 (Figs. 1, 3). Moderate 11 -HSD1 mRNA expression is first seen
at E16.5 in hippocampus, precerebellar area, and medulla (data not
shown). From E17.5 to E22.5, there is a gradual increase in expression
throughout the CNS, including the pituitary gland primordium. At E17.5,
there is also expression in the tegmental area (data not shown). The
pattern of 11 -HSD1 gene expression is similar between E18.5 and
E22.5 (date of birth) (Figs. 3, 5). High 11 -HSD1 mRNA expression is
observed in thalamus, neocortex, hypothalamus (particularly in the
anterior and ventral parts), pituitary gland (primordium), brainstem
(both pons and medulla areas), dorsal periaqueductal gray area,
tegmental area, spinal cord, and hippocampus (Fig.
6).

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Figure 6.
Expression of GR,
MR, 11 -HSD TYPE 2, and 11 -HSD
TYPE 1 mRNAs in the rat hippocampus at E22.5. The
following regions are labeled in the figure: striatum
(st); lateral ventricle (lv); hippocampus
(hr); dorsal hippocampus (dh); ventral
hippocampus (vh); and piriform cortex
(pc). Arrows indicate skin
tissue.
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11 -HSD activity
NAD+-dependent 11 -dehydrogenase activity
(11 -HSD2) is clearly detectable in whole brain and placental
extracts at all gestational ages examined (Fig.
7). 11 -HSD2 activity in the brain is
high at E12.5 and E14.5 but by E17.5 is dramatically reduced to ~24% of the levels observed during midgestation. 11 -HSD2 enzyme activity remains low at E20.5. The overall pattern of placental 11 -HSD2 activity was similar to that in the brain. In contrast,
NADP+-dependent 11 -dehydrogenase (11 -HSD1) was
very low in brain extracts at all gestational ages (Fig. 7).
NADPH+-dependent 11 -reductase (11 -HSD1) was
undetectable in brain extracts at all ages. However, in the liver there
was an increase in 11 -reductase activity at E17.5 (10.65 ± 1.95%) and E20.5 (29.05 ± 0.75%) (90 min incubation).

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Figure 7.
11 -Dehydrogenase activity from homogenates of
rat brain tissue (A) and placenta
(B) at ages E12.5, E14.5, E17.5, and E20.5. Cosubstrates were added at 100 µM. Note the predominant
NAD+-dependent reaction, typical of
11 -HSD2.
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Ontogeny of GR mRNA
GR mRNA expression is first seen at E12.5 in the neuroepithelium
(high levels are already present in the periphery, e.g., liver 1 d
earlier) (Fig. 2). At this stage, there is an overall increase in GR
mRNA expression throughout the body. In the CNS, high expression is
only seen in the pons (mainly posterior area), medulla (both ventral
and dorsal parts), anterior hypothalamus, spinal cord, and pituitary
gland (primordium). At E13.5, high expression of GR mRNA is also
detected in septum, preoptic area, and hippocampus (data not shown). By
E14.5, GR mRNA expression dramatically increases in the ventral part of
the spinal cord and to a lesser extent in the thalamus. GR mRNA is also
seen in the ventral isthmal area. By E15.5, there is increased GR mRNA expression in neocortex, olfactory bulb, precerebellar area,
cerebellum, choroid plexus, tegmentum, and basal glanglia (striatal and
pallidal neuroepithelia). In contrast, GR mRNA expression dramatically decreases in spinal cord and moderately decreases in the thalamus and
septum. At E16.5, GR gene expression appears in the locus coeruleus and
superior colliculus and continues to increase in septum, olfactory
bulb, neocortex, and hippocampus (Fig. 4). Expression of GR mRNA is
similar at E17.5. At E19.5, GR mRNA expression is also seen in the
pineal gland and periaqueductal gray area. Moreover, there is an
increase of GR mRNA in cerebellum. This pattern of expression persists
until E22.5. However, during this period there is a clear increase in
the level of GR expression throughout all the CNS-differentiating
fields (Figs. 4, 5).
Ontogeny of MR mRNA
MR mRNA expression is clearly absent in the CNS during
midgestation (Fig. 2). Moderate MR mRNA expression is first seen at E15.5 in pituitary gland (primordium), brainstem (medulla area), facial
motor nucleus, tegmentum, and neuroepithelium of the septum and
pallidum (data not shown). At E16.5, low expression can also be
detected in hippocampal neuroepithelium. MR mRNA expression moderately
increases by E17.5 and is first seen in the anterior hypothalamus (Fig.
4). At E19.5, MR mRNA expression dramatically increases in hippocampus,
septum, rhinencephalon (data not shown), anterior hypothalamus,
periaqueductal gray area, and brainstem (pontine and medulla)
neuroepithelium. There is also clear MR mRNA expression in the amygdala
and piriform cortex. This pattern of expression persists until E22.5
(see Fig. 6).
Plasma corticosterone levels
It was not possible for plasma corticosterone levels to be assayed
at E12.5 because of insufficient blood volume. At E14.5, corticosterone
levels were <3 nM. On E17.5 there was a clear increase in
corticosterone levels (161 nM). By E20.5 corticosterone
levels increased further to double the levels observed on E17.5 (333 nMol). The intra-assay variation was well <10%, and the
figures were consistently indicated by different dilutions of the
plasma that was pooled from at least 5 fetuses (12 for E14.5).
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DISCUSSION |
This study represents the first description of the ontogeny of
11 -HSD isozymes during prenatal rat brain development. The results
clearly demonstrate a distinct pattern of expression for each enzyme.
11 -HSD2, which potently inactivates GCs, is widely expressed in the
neuroepithelium until the beginning of the third trimester, when the
expression falls dramatically. In contrast, 11 -HSD1 mRNA (encoding
an enzyme that largely reactivates GCs in vivo) is low or
absent until late gestation. There are also precise temporal and
spatial changes in expression of GR, and later MR, during prenatal rat
brain development. The data clearly show potential time- and
locus-dependent windows for adrenal steroid hormone action on fetal
brain development via changes in both receptor expression and enzymatic
control of GC access to receptors.
GR and MR expression in fetal brain
The data confirm and extend previous findings on
corticosteroid receptor gene expression in fetal brain (Cintra et al.,
1993 ; Rene et al., 1994 ; Yi et al., 1994 ; Kitraki et al., 1996 ). In agreement with Cintra et al. (1993) , GR mRNA was found highly expressed
in the neuroepithelium of multiple brain areas (including hippocampus,
cerebellum, hypothalamus, raphe nuclei, locus coeruleus, and olfactory
bulb) during the last trimester of gestation. In addition, we found GR
mRNA expression within the septal, pallidal, and strionuclear complex
neuroepithelia during this period. The present data also extend to
earlier stages of development to reveal high GR mRNA expression during
midgestation (starting at E12.5). Previous findings have demonstrated
that GR mRNA is translated to an adult-like protein in fetal tissue,
suggesting that GR is functional and participates in developmental
processes such as cell birth, migration, differentiation, and
maturation (Meaney et al., 1985 ). Another important observation is that
toward the end of the third trimester GR mRNA expression increases
throughout the brain, including within the differentiating fields,
which coincides with the activation of the fetal HPA axis (Milkovic et
al., 1973 ). These observations support the notion that endogenous GCs
acting via GR may play a role in differentiation and maturational events during late fetal brain development. GCs may promote the transition between a proliferative and a differentiating stage by
directly inhibiting cell division as well as activating the expression
of specific genes characteristic of the differentiated mature
phenotype. Indeed, GCs have been reported in vitro to
decrease the rate of cell proliferation by preventing progression
through the cell cycle and extending the G1 phase or
G2 and M phases in non-neuronal cells (Fanger et al., 1987 ;
Vintermyr et al., 1989 ; Hatakeyama et al., 1991 ; Sanchez et al.,
1993 ).
In contrast to widespread GR gene expression, MR mRNA expression was
confined to the neuroepithelium of the septal-hippocampal system and a
few discrete areas of the anterior hypothalamus, pituitary, deep layers
of the superior colliculus, piriform cortex, and brainstem. Also in
contrast to GR mRNA expression, MR mRNA expression was very low or
absent until the last 3 d of gestation, when it became more
prominent in the hippocampus and lateral septum. Indeed, at the end of
gestation, MR was higher than GR mRNA expression in the hippocampus and
septum, confirming previous observations (Bohn et al., 1994 ). MR
binding sites have been reported in both neurons and glia in fetal
hippocampal cell cultures (Bohn et al., 1991 ), suggesting that MR mRNA
is likely to be translated. Physiological MR agonists, such as
aldosterone, affect neuronal and glial cell birth and death rates in
early postnatal dentate gyrus (see Gould and Cameron, 1996 ), and MR, as
well as GR, may regulate similar processes in the developing fetal
brain. The mechanisms of MR induction late in gestation are unknown.
Possible factors include (1) activation of the fetal HPA axis, although
MR is slightly regulated by GCs during adult life (Seckl, 1997a ), and
dexamethasone in the last trimester reduces MR gene expression in adult
life (Levitt et al., 1996 ); and (2) more likely, the contemporaneous development of neurotransmitter inputs (e.g., 5-hydroxytryptamine) that
potently controls hippocampal GR and MR expression in perinatal and
adult life (see Meaney et al., 1996 ).
11 -HSD expression in fetal brain
Previous studies suggested that the high 11 -HSD bioactivity in
whole fetal brain extracts (Burton et al., 1968 ) is comparable to the
levels in the adult kidney. Limited human studies suggest that high
11 -HSD is confined to early or midgestation and falls in the third
trimester in many tissues, including brain (Murphy, 1981 ; Stewart et
al., 1994 ). Our results demonstrate the predominance of the
NAD-dependent 11 -HSD2 isozyme throughout the midgestation fetal rat
brain, with 11 -dehydrogenase bioactivity paralleling the pattern of
11 -HSD2 mRNA expression. The high levels of 11 -HSD2 in the
neuroepithelium during midgestation are likely to profoundly attenuate
GC effects during the stage of CNS development. Similarly, abundant
11 -HSD2 in placenta during midgestation is thought to protect the
fetus from the deleterious effects of high maternal GCs by ensuring
that most maternal glucocorticoids are inactivated on crossing to the
fetus (see Seckl, 1997b ). Low plasma corticosterone levels in the fetus
during midgestation may reflect rapid inactivation of GCs by widespread
11 -HSD2 in placenta and fetal tissues. However, there is no evidence
available indicating that 11 -HSD2 is so effective as to abolish GR
activation by GCs during this period. Thus, further studies are
required to determine the relationship between brain corticosterone
levels, GR occupancy, and 11 -HSD2 activity during early fetal
development.
The present data do not support the notion that 11 -HSD2 protects
MR during brain development, because MR mRNA is not expressed when
11 -HSD2 is most abundant. Given that GR gene expression is seen from
early stages of development, and exposure of the developing fetus to
excess GCs can result in fetal death (Yang et al., 1969 ), 11 -HSD2
may be protecting the developing CNS from the adverse effects of
endogenous GCs acting via GR. Although severe brain abnormalities are
not prominent in humans with the syndrome of apparent mineralocorticoid
excess caused by deleterous mutations of the 11 -HSD2 gene (Mune et
al., 1995 ; Wilson et al., 1995 ), more subtle CNS abnormalities have not
been sought in these exceptional patients who rarely survive childhood.
certainly, poor 11 -HSD2 substrate GCs, such as dexamethasone, have
distinct programming effects on CNS maturation before birth (Levitt et al., 1996 ; Slotkin et al., 1996 ). It is also conceivable, although unlikely, that the function of 11 -HSD2 differs during development, perhaps catalyzing metabolism of putative alternative
11 -hydroxysteroid substrates. The mechanism downregulating
11 -HSD2 in fetal brain at midgestation is unclear, although
widespread silencing may be related to C and G-rich sequences reported
in the 5' region of the 11 -HSD2 gene (Brown et al., 1996 ).
Recently, Rajan et al. (1996) demonstrated 11 -HSD1 gene expression
and activity in fetal hippocampal cells in culture. The present work
confirms this observation and also demonstrates 11 -HSD1 gene
expression in other brain regions, including the thalamus, hypothalamus, pituitary, brainstem, and cortex. However, 11 -HSD1 gene expression was much lower than that of 11 -HSD2 mRNA and was
restricted to late gestation, when 11 -HSD2 mRNA expression was
declining. Interestingly, both 11 -HSD1 and MR expression increase
after fetal adrenocortical activation has occurred and circulating
fetal corticosterone levels are rising (Dupouy et al., 1975 ; Milkovic
et al., 1973 ). Previous studies have demonstrated that dexamethasone
administration, or stress, increase 11 -HSD1 mRNA expression and
enzyme bioactivity in the adult rat hippocampus (Low et al., 1994 ).
Similar GC induction of 11 -HSD1 occurs in primary rat hippocampal
cultures from E18 (Rajan et al., 1996 ). Moreover, there is a putative
glucocorticoid response element in the promoter of the rat 11 -HSD1
gene (Voice et al., 1996 ). It is thus possible that the rise in fetal
corticosterone levels during the last part of the third trimester may
induce 11 -HSD1 mRNA expression in fetal brain. 11 reduction is
clearly the predominant reaction in intact cells from a variety of
tissues, including brain, liver, and lung (Hundertmark et al., 1995 ;
Jamieson et al., 1995 ; Rajan et al., 1996 ). However, any physiological
role for the 11 -HSD1 in modulating exposure of the developing brain to GCs (either protecting against or increasing exposure to GCs) remains unclear, because 11 -HSD1 activity is barely, if at all, detected in the rat fetal brain. Because these studies were performed in homogenates of whole fetal brain, it is possible that regional differences in 11 -HSD1 activity could have been masked. Thus, at
this early point in the investigation, the presence of 11 -HSD1 in
the fetal brain seems likely, but requires further investigation.
The importance of the intrauterine environment has been emphasized by
studies showing that prenatal stress exerts long-lasting effects on a
variety of neuroendocrine and behavioral parameters (see Weinstock et
al., 1997 ). It has been postulated that these changes could be mediated
by direct effects on the developing brain after in utero
exposure to elevated levels of maternal or fetal GCs. Our data suggest
exquisite time and region-specific windows for GC action within
the developing CNS.
 |
FOOTNOTES |
Received June 23, 1997; revised Dec. 18, 1997; accepted Jan. 1, 1998.
This work was supported by grants from the Wellcome Trust/Royal Society
of Edinburgh, the Scottish Hospital Endowments Research Trust, and the
Sir Stanley and Lady Davidson Research Fund (J.R.S.), a Medical
Research Council Training Fellowship (R.W.B.), and a Karolinska
Institute Training Fellowship (R.D.). We thank Dr. Megan Holmes for
generously measuring the plasma corticosterone levels and Dr. Tommy
Olsson for kindly providing R.D. with photographic facilities.
Correspondence should be addressed to Dr. Rochellys Diaz, Department of
Medicine, Umeå University Hospital, S-901 85 Umeå, Sweden.
 |
REFERENCES |
-
Ader R,
Blackman DE
(1971)
Prenatal psychological stress and offspring behavior in rats and mice.
Science
125:698-699.
-
Agarwal A,
Monder C,
Eckstein B,
White PC
(1989)
Cloning and expression of rat cDNA encoding corticosteroid 11-dehydrogenase.
J Biol Chem
264:18939-18943[Abstract/Free Full Text].
-
Altman J,
Bayer SA
(1995)
In: Atlas of prenatal rat brain development. London: CRC.
-
Arriza JL,
Simerly RB,
Swanson LW,
Evans RM
(1988)
The neuronal mineralocorticoid receptor as a mediator of glucocorticoid response.
Neuron
1:887-900[Web of Science][Medline].
-
Barlow SM,
Knight AF,
Sullivan FM
(1978)
Delay in postnatal growth and development of offspring produced by maternal restraint stress during pregnancy in the rat.
Teratology
18:211-218[Web of Science][Medline].
-
Belluardo N,
Wu G,
Mudo G,
Hansson AC,
Pettersson R,
Fuxe K
(1997)
Comparative localization of fibroblast growth factor receptor-1,-2, and -3 mRNAs in the rat brain: in situ hybridization analysis.
J Comp Neurol
379:226-246[Web of Science][Medline].
-
Bohn MC,
Howard E,
Vielkind U,
Krozowski Z
(1991)
Glial cells express both mineralocorticoid and glucocorticoid receptors.
J Steroid Biochem Mol Biol
40:105-111[Web of Science][Medline].
-
Bohn MC,
Dean D,
Hussain S,
Giuliano R
(1994)
Development of mRNAs for glucocorticoid and mineralocorticoid receptors in rat hippocampus.
Dev Brain Res
77:157-162[Medline].
-
Brown RW,
Kotelevtsev Y,
Leckie C,
Lindsay RS,
Lyons V,
Murad P,
Mullins JJ,
Chapman KE,
Edwards CRW,
Seckl JR
(1996)
Isolation and cloning of human placental 11
-hydroxysteroid dehydrogenase-2 cDNA.
Biochem J
313:1007-1017. -
Burton AF,
Turnell RW
(1968)
11-dehydrocorticosteroids in tissues of mice.
Can J Biochem
46:497-502[Web of Science][Medline].
-
Cintra A,
Solfrini V,
Bunneman B,
Okret S,
Bortolotti F,
Gustafsson J-Å,
Fuxe K
(1993)
Prenatal development of glucocorticoid receptor gene expression and immunoreactivity in the rat brain and pituitary gland: a combined in situ hybridization and immunocytochemistry analysis.
Neuroendocrinology
57:1133-1147[Web of Science][Medline].
-
de Kloet ER
(1991)
Brain corticosteroid receptor balance and homeostatic control.
Front Neuroendocrinol
12:95-164[Web of Science].
-
Demeniere JM,
Piazza PV,
Guegan G,
Abrous N,
Maccari S,
Le Moal M,
Simon H
(1992)
Increased locomotor response to novelty and propensity to intravenous amphetamine self-administration in adult offspring of stressed mothers.
Brain Res
586:135-139[Web of Science][Medline].
-
Diaz R,
Fuxe K,
Ögren SV
(1997)
Prenatal cortcosterone treatment induces long-term changes in spontaneous and apomorphine-mediated motor activity in male and female rats.
Neuroscience
81:129-140[Web of Science][Medline].
-
Dupouy JP,
Coffigny H,
Magre S
(1975)
Maternal and fetal corticosterone levels during late pregnancy in rats.
J Endocrinol
65:347-352[Abstract/Free Full Text].
-
Fanger BO,
Schreifer J,
Cidlowski JA
(1987)
Glucocorticoids increase the length of the G2 and M phases of the HeLa S3 cell cycle.
J Steroid Biochem Mol Biol
28:345-347.
-
Gould E,
Cameron HA
(1996)
Regulation of neuronal birth, migration, and death in the rat dentate gyrus.
Dev Neurosci
18:22-35[Web of Science][Medline].
-
Hatakeyama S,
Susuki A,
Yoshizumi N,
Sato M,
Nishiya I
(1991)
Glucocorticoid-induced G1 arrest and the release effect of epidermal growth factor on human salivary gland adrenocarcinoma cell.
Cell Biol Int Rep
15:55-65[Web of Science][Medline].
-
Holmes Mg,
French K,
Seckl JR
(1997)
Dysregulation of serotonin 5-HT2C and corticosteroid receptor gene expression in the hippocampus with food restriction and glucocorticoids.
J Neurosci
17:4046-4065.
-
Holsboer F,
Grasser A,
Friess E,
Wiedemann K
(1994)
Steroid effects on central neurons and implications for psychiatric and neurological disorders.
Ann NY Acad Sci
746:345-359[Web of Science][Medline].
-
Hundertmark S,
Buhler H,
Ragosch V,
Dinkelborg L,
Arabin B,
Weitzel HK
(1995)
Correlation of surfactant phosphatidylcholine synthesis and 11
-hydroxysteroid dehydrogenase in fetal lung.
Endocrinology
136:2573-2578[Abstract]. -
Jamieson PM,
Chapman KE,
Edwards CRW,
Seckl JR
(1995)
11
-Hydroxysteroid dehydrogenase is an exclusive 11-reductase in primary cultures of rat hepatocytes: effect of physicochemical and hormonal manipulations.
Endocrinology
136:4754-4760[Abstract]. -
Kitraki E,
Alexis MN,
Stylianopoulou F
(1996)
Glucocorticoid receptor gene expression in the embryonic rat brain.
Neuroendocrinology
63:305-317[Web of Science][Medline].
-
Lakshmi V,
Sakai RR,
McEwen BS
(1991)
Regional distribution of 11
-hydroxysteroid dehydrogenase in rat brain.
Endocrinology
128:1741-1748[Abstract/Free Full Text]. -
Leckie C,
Chapman KE,
Edwards CRW,
Seckl JR
(1995)
LLC-PK1 cells model 11-hydroxysteroid dehydrogenase type 2 regulation of glucocorticoid access to renal mineralocorticoid receptors.
Endocrinology
136:5561-5569[Abstract].
-
Levitt N,
Lindsay RS,
Holmes MC,
Seckl JR
(1996)
Dexamethasone in the last week of pregnancy attenuates hippocampal glucocorticoid receptor gene expression and elevates blood pressure in the adult offspring in the rat.
Neuroendocrinology
64:412-418[Web of Science][Medline].
-
Lindsay RS,
Lindsay RM,
Edwards CRW,
Seckl JR
(1996a)
Inhibition of 11
-hydroxysteroid dehydrogenase in pregnant rats and the programming of blood pressure in the offspring.
Hypertension
27:1200-1204[Abstract/Free Full Text]. -
Lindsay RS,
Lindsay RM,
Waddel B,
Seckl JR
(1996b)
Programming of glucose tolerance in the rat: role of placental 11
-hydroxysteroid dehydrogenase.
Diabetologia
39:1299-1305[Web of Science][Medline]. -
Low SC,
Moisan M-P,
Edwards CRW,
Seckl JR
(1994)
Glucocorticoids and chronic stress upregulate 11
-hydroxysteroid dehydrogenase activity and gene expression in the hippocampus.
J Neuroendocrinol
6:275-290[Web of Science][Medline]. -
Meaney Mj,
Sapolsky RM,
Aiteken DH,
McEwen BS
(1985)
3H- Dexamethasone binding in the limbic brain of the fetal rat.
Dev Brain Res
23:297-300.
-
Meaney MJ,
Diorio J,
Francis D,
Widdowson J,
La Plante P,
Caldji C,
Sharma S,
Seckl JR,
Plotsky PM
(1996)
Early environmental regulation of forebrain glucocorticoid receptor gene expression: implications for adrenocortical responses to stress.
Dev Neurosci
18:49-72[Web of Science][Medline].
-
Milkovic S,
Milkovic K,
Paunovic J
(1973)
The initiation of fetal adrenocortrophic activity in the rat.
Endocrinology
92:380-384[Abstract/Free Full Text].
-
Moisan M-P,
Seckl JR,
Edwards CRW
(1990)
11
-Hydroxysteroid dehydrogenase bioactivity and messenger RNA expression in rat forebrain: localization in hypothalamus, hippocampus, and cortex.
Endocrinology
127:1450-1455[Abstract/Free Full Text]. -
Moisan M-P,
Edwards CRW,
Seckl JR
(1992)
Ontogeny of 11
-hydroxysteroid dehydrogenase in rat brain and kidney.
Endocrinology
130:400-444[Abstract/Free Full Text]. -
Mune T,
Rogerson FM,
Nikkilä H,
Agarwal AK,
White PC
(1995)
Human hypertension caused by mutations in the kidney isozyme of 11
-hydroxysteroid dehydrogenase.
Nat Genet
10:394-399[Web of Science][Medline]. -
Murphy BE
(1981)
Ontogeny of cortisol-cortisone interconversion in humans tissues: a role for cortisone in human fetal development.
J Steroid Biochem Mol Biol
14:811-817[Web of Science].
-
Phillips DIW,
Barker DJP,
Fall CHD,
Whorwood CB,
Walker BR,
Wood PJ
(1997)
Low birth weight and raised plasma concentrations in adult life.
Diabetologia
40:830[Web of Science][Medline].
-
Rajan V,
Edwards CRW,
Seckl JR
(1996)
11
-Hydroxysteroid dehydrogenase in cultured hippocampal cells reactivates inert 11-dehydrocorticosterone, potentiating neurotoxicity.
J Neurosci
16:65-70[Abstract/Free Full Text]. -
Rene F,
Hindelang C,
Stoeckel ME,
Felix JM
(1994)
Ontogeny of glucocorticoid and D2 receptors in the rat pituitary: an in situ hybridization study.
Mol Cell Endocrinol
105:65-75[Web of Science][Medline].
-
Sanchez I,
Goya L,
Vallerga AK,
Firestone GL
(1993)
Glucocorticoids reversibly arrest rat hepatoma cell growth by inducing an early G1 block in cell cycle progression.
Cell Growth Differ
4:215-225[Abstract].
-
Seckl JR
(1997a)
11
-hydroxysteroid dehydrogenase in the rat brain: a novel regulator of glucocorticoid action.
Front Neuroendocrinol
18:49-99[Web of Science][Medline]. -
Seckl JR
(1997b)
Glucocorticoids, feto-placental 11
-hydroxysteroid dehydrogenase type 2, and the early life origins of adult diseases.
Steroids
62:89-94[Web of Science][Medline]. -
Seckl JR,
Olsson T
(1997)
Glucocorticoid hypersecretion and the age-impaired hippocampus: cause or effect?
J Endocrinol
145:201-211.
-
Seckl JR,
Dickson KL,
Fink G
(1990)
Central 5,7-dihydroxytryptamine lesions decrease hippocampal glucocorticoid and mineralocorticoid receptor messenger ribonucleic acid expression.
J Neuroendocrinol
2:911-916[Web of Science][Medline].
-
Slotkin TA,
Barnes GA,
McCook EC,
Seidler FJ
(1996)
Programming of brainstem serotonin transporter development by prenatal glucocorticoids.
Dev Brain Res
93:155-161[Medline].
-
Stewart PM,
Murry BA,
Mason JI
(1994)
Type 2 11
-hydroxysteroid dehydrogenase in human tissues.
J Clin Endocrinol Metab
78:1529-1532[Abstract]. -
Vintermyr OK,
Doskeland SO
(1989)
Characterization of inhibitory effect of glucocorticoids on the DNA replication of adult rat hepatocytes growing at various cell densities.
J Cell Physiol
138:29-37[Web of Science][Medline].
-
Voice MW,
Seckl JR,
Edwards CRW,
Chapman KE
(1996)
11
-Hydroxysteroid dehydrogenase Type I expression in 2S FAZA hepatoma cells is hormonally regulated; a model system for the study of hepatic glucocorticoid metabolism.
Biochem J
317:621-625. -
Weinstock M
(1997)
Does prenatal stress impair coping and regulation of hypothalamic-pituitary-adrenal axis?
Neurosci Behav Rev
21:1-10[Web of Science][Medline].
-
White PC,
Mune T,
Agarwal AK
(1997)
11
-hydroxysteroid dehydrogenase and the syndrome of apparent mineralocorticoid excess.
Endocr Rev
18:135-156[Abstract/Free Full Text]. -
Wilson RC,
Harbison MD,
Krowski ZS,
Funder JW,
Shackleton CHL,
HanauskeAbel HM,
Wei JQ,
Hertecant J,
Moran A,
Neiberger RE,
Balfe JW,
Fattah A,
Daneman D,
Licholai T,
New MI
(1995)
Several homozygous mutations in the gene for 11beta-hydroxysteroid dehydrogenase type 2 in patients with apparent mineralocorticoid excess.
J Clin Endocrinol Metab
80:3145-3150[Abstract].
-
Yang WH,
Yang WP,
Lin LL
(1969)
Interruption of pregnancy in the rat by administration of ACTH.
Endocrinology
84:1282-1285[Abstract/Free Full Text].
-
Yi SY,
Masters JN,
Baram TZ
(1994)
Glucocorticoid receptor mRNA ontogeny in fetal and postnatal rat forebrain.
Mol Cell Neurosci
5:385-393[Web of Science][Medline].
-
Zarrow MX,
Philpott JE,
Denenberg VH
(1970)
Passage of 14C-4-corticosterone from the rat mother to the fetus and neonate.
Nature
226:1058-1059[Medline].
Copyright © 1998 Society for Neuroscience 0270-6474/98/1872570-11$05.00/0
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