Opposite effects of glucocorticoid on hepatic 11 β-hydroxysteroid dehydrogenase mRNA and activity in fetal and adult sheep

1994 ◽  
Vol 143 (1) ◽  
pp. 121-126 ◽  
Author(s):  
K Yang ◽  
E T M Berdusco ◽  
J R G Challis
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Reductase Activity ◽  
Mrna Level ◽  
Hydroxysteroid Dehydrogenase ◽  
Fetal Life ◽  
Mrna Levels ◽  
Fetal Sheep ◽  
Adult Sheep ◽  
Hepatic Level

Abstract The level of 11 β-hydroxysteroid dehydrogenase (11β-HSD) mRNA in the fetal sheep liver increases dramatically between day 130 and term (term=day 145), but the causal factors remain unknown. The present study was designed to determine the effects of exogenous glucocorticoid on the fetal hepatic 11 β-HSD gene expression. Dexamethasone (dex; 2 μg/min over 15 min every 2 h) or saline was infused into chronically-catheterized fetal sheep at day 130 of gestation for 4 days. At the end of infusion, the lower right lobe of the liver was collected, total cellular RNA extracted and subjected to Northern blot analysis. It was found that the level of the hepatic 11 β-HSD mRNA in dex-treated fetuses was about four times higher than that in the saline-treated controls. To examine whether changes occur in the response of hepatic 11 β-HSD gene expression to glucocorticoids in adulthood, we also treated non-pregnant ewes with dex (10 mg/day) for 4 days. By contrast, this treatment regime in adult sheep produced a small but significant decrease in hepatic 11 β-HSD mRNA levels. We also determined whether age-specific changes in the hepatic level of 11 β-HSD mRNA following dex treatment were reflected in the level of 11 β-HSD enzyme activity. Hepatic 11 β-HSD activity was determined by a standard in vitro conversion assay using cortisol and cortisone as physiological substrates. In both fetal and adult livers, 11-oxoreductase activity (cortisone→cortisol) was predominant. Following dex treatment, there was a significant increase in the fetal hepatic level of both 11β-dehydrogenase (cortisol→cortisone) and 11-oxoreductase activities. Furthermore, the C-11 activation index, an indicator of glucocorticoid net gain, was also increased in the fetal liver by dex. In marked contrast, dex treatment in the adult did not alter the C-11 activation index though it produced a significant decrease in the hepatic level of both 11 β-dehydrogenase and reductase activities. In summary, these results indicate that (1) exogenous glucocorticoid exerts opposite effects on hepatic 11 β-HSD gene expression in fetal and adult sheep; (2) dex-induced age-specific changes in the level of 11β-HSD mRNA are carried though to the level of 11β-HSD protein; and (3) since 11 β-HSD reductase activity is predominant in both fetal and adult sheep livers, the liver may be a potential extra-adrenal source of cortisol. Furthermore, we speculate that (1) the dramatic increase in the fetal hepatic 11 β-HSD mRNA level at term may be due to the elevated fetal plasma concentration of glucocorticoid; and (2) glucocorticoid-induced increases in the fetal hepatic 11β-HSD gene expression and the resultant increase in the C-11 activation index during the last days of fetal life may play a crucial role in fetal organ maturation and in the endocrine mechanisms leading to parturition. Journal of Endocrinology (1994) 143, 121–126

Developmental regulation of preproenkephalin (PENK) gene expression in the adrenal gland of the ovine fetus and newborn lamb: effects of hypoxemia and exogenous cortisol infusion

1997 ◽  
Vol 155 (1) ◽  
pp. 143-149 ◽  
Author(s):  
M Fraser ◽  
SG Matthews ◽  
G Braems ◽  
T Jeffray ◽  
Keyword(s):  
Gene Expression ◽  
Adrenal Gland ◽  
Plasma Cortisol ◽  
Late Gestation ◽  
Mrna Levels ◽  
Fetal Sheep ◽  
Adult Sheep ◽  
Organ Systems ◽  
Response To Stress ◽  
In Pregnancy

Development of the fetal adrenal gland is crucial not only for maturation of several fetal organ systems and the initiation of parturition, but also for the development of the fetal response to stress. The enkephalin-related peptides are present in the chromaffin cells of the fetal adrenal medulla and are secreted in response to stress and with sympathetic stimulation. However, changes in expression of preproenkephalin (PENK) with gestation and in response to stress have not been studied in detail. Therefore we examined the developmental pattern of PENK gene expression in the adrenal gland of fetal and newborn lambs, and of adult sheep. We also determined whether levels of PENK mRNA in the fetal adrenal gland changed in response to exogenous glucocorticoids in late gestation, or in response to hypoxemia. Adrenal glands were removed from fetal sheep, lambs and adult sheep at different stages of development for measurement of PENK mRNA. Cortisol was infused (5 micrograms/min) for 12, 24 or 96 h beginning on day 124-129 of gestation. Moderate hypoxemia was induced for 48 h beginning on day 126-130, or at day 134-136 of gestation, by lowering the maternal fractional inspired oxygen. At the end of the treatment periods, the ewes and fetuses were euthanized. Adrenal PENK mRNA were measured by Northern blot analysis. PENK mRNA levels in fetal adrenals were significantly higher (P < 0.05) on days 140-141 of gestation than earlier in pregnancy, and then decreased significantly with the onset of parturition (days 142-146). After cortisol infusion to the fetus for 96 h there was a significant reduction in adrenal PENK mRNA levels. Hypoxemia resulted in a significant increase in PENK mRNA levels in fetuses at day 126-130 of gestation, but not at the later time in pregnancy when endogenous plasma cortisol concentrations were higher. We conclude that there is a decrease in levels of PENK mRNA in the fetal adrenal gland before parturition at the time of the endogenous prepartum rise in plasma cortisol. Hypoxemia led to an elevation of PENK mRNA levels in fetuses at less than 130 days, but after that time, when the basal and stimulated cortisol responses had risen, there was no significant effect of hypoxemia on PENK mRNA. Cortisol infusion to the fetus at this stage of pregnancy resulted in a decrease in adrenal PENK mRNA levels. We suggest that cortisol may play an important role in the regulation of fetal adrenal PENK mRNA levels and enkephalin synthesis by the adrenal gland of the fetal sheep.

Alcohol exposure during late ovine gestation alters fetal liver iron homeostasis without apparent dysmorphology

2013 ◽  
Vol 304 (12) ◽  
pp. R1121-R1129 ◽  
Author(s):  
Foula Sozo ◽  
Anna M. Dick ◽  
Jonathan G. Bensley ◽  
Kelly Kenna ◽  
James F. Brien ◽  
...  
Keyword(s):  
Gene Expression ◽  
Iron Homeostasis ◽  
Ferric Iron ◽  
Fetal Liver ◽  
Alcohol Exposure ◽  
Ethanol Exposure ◽  
Fetal Life ◽  
Mrna Levels ◽  
Liver Morphology ◽  
Iron Concentrations

High levels of alcohol (ethanol) exposure during fetal life can affect liver development and can increase susceptibility to infection after birth. Our aim was to determine the effects of a moderate level of ethanol exposure in late gestation on the morphology, iron status, and inflammatory status of the ovine fetal liver. Pregnant ewes were chronically catheterized at 91 days of gestation (DG; term ∼145 DG) for daily intravenous infusion of ethanol (0.75 g/kg maternal body wt; n = 8) or saline ( n = 7) over 1 h from 95 to 133 DG. At necropsy (134 DG), fetal livers were collected for analysis. Liver weight, general liver morphology, hepatic cell proliferation and apoptosis, perivascular collagen deposition, and interleukin ( IL) -1β, IL-6, or IL-8 mRNA levels were not different between groups. However, ethanol exposure led to significant decreases in hepatic content of ferric iron and gene expression of the iron-regulating hormone hepcidin and tumor necrosis factor ( TNF) -α (all P < 0.05). In the placenta, there was no difference in transferrin receptor, divalent metal transporter 1, and ferritin mRNA levels; however, ferroportin mRNA levels were increased in ethanol-exposed animals ( P < 0.05), and ferroportin protein tended to be increased ( P = 0.054). Plasma iron concentration was not different between control and ethanol-exposed groups; control fetuses had significantly higher iron concentrations than their mothers, whereas maternal and fetal iron concentrations were similar in ethanol-exposed animals. We conclude that daily ethanol exposure during the third-trimester-equivalent in sheep does not alter fetal liver morphology; however, decreased fetal liver ferric iron content and altered hepcidin and ferroportin gene expression indicate that iron homeostasis is altered.

Differential expression of 11β-hydroxysteroid dehydrogenase 1 and 2 in the developing ovine fetal liver and kidney

1995 ◽  
Vol 147 (3) ◽  
pp. 405-411 ◽  
Author(s):  
D A Langlois ◽  
S G Matthews ◽  
M Yu ◽  
K Yang
Keyword(s):  
Dehydrogenase Activity ◽  
Fetal Liver ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Fetal Kidney ◽  
Fetal Sheep ◽  
Parallel Increase ◽  
Tissue Homogenates ◽  
Liver And Kidney ◽  
Ovine Fetal

Abstract In adult mammals, liver and kidney are the two major sites of biosynthesis for 11β-hydroxysteroid dehydrogenase (11β-HSD) 1 and 2 respectively. In the present study, the expression of these two isozymes in the developing ovine fetal liver and kidney was characterized. Livers and kidneys were obtained from fetal sheep at days 85, 100–120 and 140–143 of gestation (term=145 days). Tissue levels of 11β-HSD2 mRNA were assessed by Northern blot analysis. 11β-HSD dehydrogenase and reductase activities in tissue homogenates were determined by a radiometric conversion assay using cortisol and cortisone as physiological substrates respectively. The unidirectional 11β-HSD2 dehydrogenase activity was identified by its distinct co-factor preference (NAD), and by its unique ability to metabolize dexamethasone (Dex). In the liver, 11β-HSD1 dehydrogenase and reductase activities were present by day 85, and their levels did not change between days 85 and 100–120 but increased more than twofold at days 140–143. This was consistent with changes we reported previously in the fetal hepatic 11β-HSD1 mRNA. 11β-HSD1 reductase activity was always higher than the dehydrogenase activity. 11β-HSD2 mRNA and activity were undetectable in the fetal liver at all three ages. By contrast, 11β-HSD2 mRNA was present in the fetal kidney by day 85, and its abundance increased progressively thereafter. There was a parallel increase in the renal 11β-HSD2 activity. Dex was also converted to 11-dehydro-Dex by the fetal kidney. In keeping with the absence of the full-length 11β-HSD1 mRNA, 11β-HSD1 activity was undetectable in the kidney. These results indicate that (1) 11β-HSD1 and 2 genes are differentially expressed and regulated in the fetal liver and kidney during development, (2) since the hepatic 11β-HSD1 reductase activity is always higher than the dehydrogenase activity, the fetal liver may be a potential extra-adrenal source of cortisol, and (3) 11β-HSD2 in the kidney may play a very important role in protecting the fetus from elevated levels of bioactive glucocorticoids. Journal of Endocrinology (1995) 147, 405–411

Circulating insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs) and tissue mRNA levels of IGFBP-2 and IGFBP-4 in the ovine fetus

1995 ◽  
Vol 145 (3) ◽  
pp. 545-557 ◽  
Author(s):  
J M Carr ◽  
J A Owens ◽  
P A Grant ◽  
P E Walton ◽  
P C Owens ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Mrna Level ◽  
Common Factor ◽  
Late Gestation ◽  
Mrna Levels ◽  
Igf Binding Proteins ◽  
Fetal Sheep ◽  
Igf I ◽  
Igf Binding ◽  
Igfbp 3

Abstract The IGF-binding proteins (IGFBPs) are a family of at least six structurally related proteins, which bind the IGFs and modulate their actions, including the regulation of preand postnatal growth. In this study we have examined the relationship between circulating and tissue mRNA levels of IGFBPs and related this to circulating IGFs in the fetal sheep over the gestational period when rapid growth and development occurs. Circulating IGFBP-2, as measured by Western ligand blot (WLB), increases between early and mid gestation, remains high, then declines throughout late gestation (P=0·0002). Circulating IGFBP-3 increases throughout gestation, as measured by WLB or RIA (P=0·04 and P=0·0001 respectively), as does circulating IGFBP-4 (P=0·004). These ontogenic changes in circulating IGFBPs-2 and -4 are paralleled by changes in liver mRNA for these proteins and, for IGFBP-2, by those in kidney IGFBP-2 mRNA also. This suggests that liver and kidney may be the primary contributors to circulating IGFBP-2 and the liver to circulating IGFBP-4. IGFBP-2 mRNA is present in the heart and lung in early gestation but barely detectable in these tissues after approximately 60 days gestation. IGFBP-4 mRNA is also present in the heart in early but not late gestation, but is abundant in the lung throughout gestation. These results demonstrate tissue specific and developmental regulation of IGFBPs-2 and -4 at the mRNA level. To assess any role the circulating IGFs may play in mediating these changes in IGFBPs, or vice versa, both plasma IGF-I and IGF-II were measured by RIA. Circulating IGF-I increases as gestation progresses (P=0·0001), while circulating IGF-II increases between early and mid gestation, remains high (P=0·01), then declines. Circulating IGF-I is positively correlated with fetal weight (r=0·66, P=0·03), circulating IGFBP-3 (r=0·54, P=0·01) and IGFBP-4 (r=0·52, P=0·01). Circulating IGF-II positively correlates with circulating IGFBP-2 (r=0·48, P=0·02) throughout gestation and at 1 day postnatally. These relationships are consistent with circulating IGF-I influencing IGFBPs-3 and -4, and similarly, IGF-II determining IGFBP-2, or vice versa. Alternatively, these correlations may reflect coordinate regulation of IGF and IGFBP by a common factor. Journal of Endocrinology (1995) 145, 545–557

Specificity of a placental factor inhibiting breathing in fetal sheep

1996 ◽  
Vol 8 (3) ◽  
pp. 423 ◽  
Author(s):  
RE Alvaro ◽  
V Rehan ◽  
Almeida V de ◽  
Z Haider ◽  
M Robertson ◽  
...  
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Fetal Liver ◽  
Fetal Life ◽  
Krebs Solution ◽  
Fetal Sheep ◽  
Electrocortical Activity ◽  
Fetal Breathing ◽  
Pregnant Ewe ◽  
Placental Extract

We have found previously that the infusion of a placental extract inhibits breathing induced by 100% O2 plus umbilical cord occlusion in the fetal sheep, suggesting that a placental factor is responsible for the inhibition of fetal breathing. To test whether this factor is specific to the placenta and whether it also inhibits spontaneous fetal breathing (occurring in the absence of cord occlusion), we administered extracts from the placenta, muscle and liver of the pregnant ewe, extracts of fetal liver, and Krebs solution to 16 chronically instrumented fetal sheep at 135 +/- 5 days of gestation. Infusions were made during low-voltage electrocortical activity, 5 to 15 min after a switch from high voltage, when breathing was well established. Within 90 s of the infusion of the placental extract in the carotid artery of the fetus, breathing decreased in 79% (33/42) of the experiments and was completely abolished in 71% (30/42) of them (P < 0.0001 compared with the other infusates). No apnoeas were observed with the Krebs solution (0/19) and the maternal muscle (0/20). Extracts of maternal and fetal liver abolished breathing in only 17% (4/23) and 21% (6/29) of the experiments respectively (NS compared with Krebs solution). There were no significant changes in blood gas tensions, pH, blood pressure and heart rate associated with the infusion of the extracts. The electrocortical activity (ECoG) switched from low to high voltage in 50% of the experiments using placental extract compared with 0% with Krebs solution and maternal muscle, and with 9% and 17% with maternal and fetal liver respectively (P < 0.005). Breathing output (integral of EMGdi x f) during and after the infusions significantly decreased only with the placental extract. These findings indicate the presence of a factor produced by the placenta which inhibits fetal breathing and may be responsible for the normal inhibition of breathing observed in fetal life.

Altered corticosteroid metabolism differentially affects pituitary corticotropin response

2002 ◽  
Vol 282 (2) ◽  
pp. E466-E473 ◽  
Author(s):  
Junko Hanafusa ◽  
Tomoatsu Mune ◽  
Tetsuya Tanahashi ◽  
Yukinori Isomura ◽  
Tetsuya Suwa ◽  
...  
Keyword(s):  
Glycyrrhizic Acid ◽  
Mrna Level ◽  
Hydroxysteroid Dehydrogenase ◽  
Corticotropin Releasing Factor ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Basal Plasma ◽  
Corticosterone Response ◽  
Pituitary Adrenal Axis

To evaluate the effects of altered corticosteroid metabolism on the hypothalamic-pituitary-adrenal axis, we examined rats treated with glycyrrhizic acid (G rats) or rifampicin (R rats) for 7 days. The half-life of exogenously administered hydrocortisone as a substitute for corticosterone was longer in G rats and shorter in R rats, with no differences in basal plasma levels of ACTH or corticosterone. The ACTH responses to human corticotropin-releasing factor (CRF) or insulin-induced hypoglycemia were greater in G rats and tended to be smaller in R rats compared with those in the control rats, whereas the corticosterone response was similar. No difference was observed in the content and mRNA level of hypothalamic CRF among the groups. The number and mRNA level of CRF receptor and type 1 11β-hydroxysteroid dehydrogenase (11-HSD1) mRNA level in the pituitary were increased in G rats but not changed in R rats, suggesting that chronically increased intrapituitary corticosterone upregulates pituitary CRF receptor expression. In contrast, CRF mRNA levels in the pituitary were increased in R rats. Our data indicate novel mechanisms of corticosteroid metabolic modulation and the involvement of pituitary 11-HSD1 and CRF in glucocorticoid feedback physiology.

Changes in lung expansion alter pulmonary DNA synthesis and IGF-II gene expression in fetal sheep

1993 ◽  
Vol 265 (4) ◽  
pp. L403-L409 ◽  
Author(s):  
S. B. Hooper ◽  
V. K. Han ◽  
R. Harding
Keyword(s):  
Gene Expression ◽  
Dna Synthesis ◽  
Fetal Lung ◽  
Liquid Volume ◽  
Mrna Levels ◽  
Pulmonary Tissue ◽  
Fetal Sheep ◽  
Tracheal Obstruction ◽  
Lung Expansion ◽  
Lung Liquid

Our aim was to determine the effect of short-term (7 days) alterations in fetal lung liquid volume on pulmonary DNA synthesis rates and insulin-like growth factor-II (IGF-II) mRNA levels. Fifteen chronically catheterized fetal sheep were divided into three groups. In one, the trachea was obstructed, in another lung liquid was drained by gravity, and the third group served as controls. After 7 days, [3H]thymidine was injected into each fetus and 8 h later fetal tissues were collected. Fetal lung-to-body weight ratios and total lung DNA contents were greatly increased in fetuses with tracheal obstruction compared with control fetuses, whereas the drainage of lung liquid did not affect these measurements. DNA synthesis rates in pulmonary tissue were significantly reduced from a mean control value of 153.3 +/- 25.1 disintegrations per minute (dpm)/microgram DNA to 57.2 +/- 8.6 dpm/microgram DNA by lung liquid drainage (P < 0.05) and were significantly increased to 236.0 +/- 24.0 dpm/microgram DNA by tracheal obstruction (P < 0.05). Following tracheal obstruction, lung IGF-II mRNA levels were increased to 177.0 +/- 18.2% (P < 0.05) of the mean value for control fetuses, whereas they were reduced to 56.1 +/- 7.1% of control in lung liquid-drained fetuses. We conclude that altering fetal lung expansion has a potent and rapid effect on pulmonary DNA synthesis and that this effect may, in part, be mediated by an alteration in IGF-II gene expression.

scholarly journals Differential Gene Expression of Steroid 5α-Reductase 2 in Core Needle Biopsies from Malignant and Benign Prostatic Tissue1

1997 ◽  
Vol 82 (7) ◽  
pp. 2210-2214
Author(s):  
Catarina Bjelfman ◽  
Torbjörn G. Söderström ◽  
Einar Brekkan ◽  
Bo Johan Norlén ◽  
Lars Egevad ◽  
...  
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Mrna Level ◽  
Transrectal Ultrasound ◽  
Mrna Levels ◽  
Prostate Hyperplasia ◽  
Noncancerous Tissue ◽  
Core Needle ◽  
Total Rna ◽  
Prostate Diseases

Androgens are implicated in the development of prostate cancer (CAP) and benign prostate hyperplasia. The conversion of testosterone to the more potent metabolite dihydrotestosterone by prostate-specific steroid 5α-reductase type 2 (5α-red2) is a key mechanism in the action of androgens in the prostate and is important in the promotion and progression of prostate diseases. Manipulation of the turnover of androgens is thus fundamental in the pharmacological treatment strategy. We have developed a sensitive solution hybridization method for quantification of the gene expression of 5α-red2 in core needle biopsies of the prostate. The 5α-red2-specific messenger RNA (mRNA) levels were measured in 50 human prostate transrectal ultrasound-guided core biopsies obtained from 31 outpatients (median age 72, range 57–88 yr) undergoing biopsy for diagnostic purposes. Significant differences were observed in the gene expression of 5α-red2 between cancerous and noncancerous tissue. In the 14 biopsies judged cancerous, the median 5α-red mRNA levels were 3.5 amol/ng total RNA compared with 12.0 amol/ng total RNA in the biopsies showing no cancer (P = 0.0018). The median 5α-red2 mRNA level in noncancerous tissue was thus 3.4 times higher than in the cancerous specimens.

Developmental expression of pIgR gene in sheep mammary gland and hormonal regulation

2002 ◽  
Vol 69 (1) ◽  
pp. 13-26 ◽  
Author(s):  
AURORE RINCHEV-ALARNOLD ◽  
LUCETTE BELAIR ◽  
JEAN DJIANE
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Hormonal Regulation ◽  
Mrna Level ◽  
Immunohistochemical Analysis ◽  
Developmental Expression ◽  
Secretory Iga ◽  
Mrna Levels ◽  
Immunoglobulin Receptor ◽  
Pregnancy And Lactation

Secretory IgA found in external secretions are constituted by polymeric IgA (pIgA) bound to the extra-cellular part of the polymeric immunoglobulin receptor (pIgR). The receptor mediates transcytosis of pIgA across epithelial cells. The aim of the present study was to analyse the evolution of pIgR expression in the sheep mammary gland during the development of the mammary gland and to analyse its hormonal regulation. Gene expression of the pIgR was analysed in sheep mammary gland during pregnancy and lactation. By Northern Blot analysis, we observed that low levels of pIgR mRNA are expressed until day 70 of pregnancy. Accumulation of pIgR mRNA started during the third part of pregnancy and intensified 3 d after parturition to reach highest levels during established lactation (day 70). In situ hybridization analysis was used to confirm the increase in pIgR gene expression per mammary epithelial cell. In order to examine the hormonal regulation of the pIgR expression, virgin ewes were hormonally treated. Treatment with oestradiol and progesterone increased pIgR mRNA levels slightly. Subsequent addition of glucocorticoids induced a significant accumulation of pIgR mRNA in the mammary gland of the treated animals. Immunohistochemical analysis was performed to verify that the increase of pIgR mRNA level was associated with enhancement of the pIgR protein in mammary cells. No increase of pIgR mRNA levels were observed if PRL secretion was blocked by bromocryptine injections throughout the hormonal procedure. In conclusion, the present experiments suggest that the enhancement of pIgR levels during lactation result from combined effects of both prolactin and glucocorticoids.

scholarly journals Enhancement of Cortisol-Induced 11β-Hydroxysteroid dehydrogenase Type 1 Expression by Interleukin 1β in Cultured Human Chorionic Trophoblast Cells

Endocrinology ◽  
2006 ◽  
Vol 147 (5) ◽  
pp. 2490-2495 ◽  
Author(s):  
Wenjiao Li ◽  
Lu Gao ◽  
Yan Wang ◽  
Tao Duan ◽  
Leslie Myatt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phospholipase A2 ◽  
Mrna Expression ◽  
Reporter Gene ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Cytosolic Phospholipase A2 ◽  
Trophoblast Cells ◽  
Cytosolic Phospholipase

Chorion is the most abundant site of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) expression within intrauterine tissues. It is important to study the regulation of 11β-HSD1 expression in the chorion in terms of local cortisol production during pregnancy. Using real-time PCR and enzyme activity assay, we found that cortisol (1 μm) and IL-1β (10 ng/ml) for 24 h significantly increased 11β-HSD1 mRNA expression and reductase activity in cultured human chorionic trophoblasts. A further significant increase of 11β-HSD1 mRNA expression and reductase activity was observed with cotreatment of cortisol and IL-1β. To explore the mechanism of induction, 11β-HSD1 promoter was cloned into pGL3 plasmid expressing a luciferase reporter gene. By transfecting the constructed vector into WISH cells, an amnion-derived cell line, we found that cortisol (1 μm) or IL-1β (10 ng/ml) significantly increased reporter gene expression. Likewise, an additional increase in reporter gene expression was observed with cotreatment of cortisol and IL-β. To explore the physiological significance of 11β-HSD1 induction in the chorion, we studied the effect of cortisol on cytosolic phospholipase A2 and cyclooxygenase 2 expression. We found that treatment of chorionic trophoblast cells with cortisol (1 μm) induced both cytosolic phospholipase A2 and cyclooxygenase 2 mRNA expression. We conclude that cortisol up-regulates 11β-HSD1 expression through induction of promoter activity, and the effect was enhanced by IL-1β, suggesting that more biologically active glucocorticoids could be generated in the fetal membranes in the presence of infection, which may consequently feed forward in up-regulation of prostaglandin synthesis.

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