| Adverse intrauterine environment during pregnancy could cause fetal a variety of adverse pregnant outcomes, such as premature delivery and intrauterine growth retardation (IUGR). IUGR is one of the most common developmental toxicity, which cause children detriment in the near future (increased the perinatal fetus mortality) and the harm will also continue to after birth, manifest as physical and mental development retardation as well as increased susceptibility to adult metabolic syndrome after birth. More and more researches suggest that programming alteration of the hypothalamic-pituitary-adrenal (HPA) axis may be the key mechanism of IUGR offspring susceptible to the metabolic syndrome in adults. As the terminal effect organ of HPA axis, adrenal is the earliest and fastest development part in fetal HPA axis, which is responsible for the steroidogenesis. Studies suggest that IUGR offspring induced by adverse intrauterine environment exposure during pregnancy had adrenal dysplasia, and increased risk of postnatal metabolic syndrome. Therefore, fetal adrenal function development status and the basal glucocorticoid (GC) level during intrauterine growth period is the key to decide the fetal tissue maturity and its fate after birth.Currently, caffeine is widespread in coffee, tea and soft drinks and caffeine consumption through various means is a common life behavior for human. It has been shown that prenatal caffeine exposure (PCE) exist serious developmental toxicity, and is one of the unequivocal causes of IUGR. Furthermore, PCE could cause a variety of adverse fetal outcomes, including morphological abnormalities and fetal growth retardation. We have previously demonstrated that PCE can cause IUGR fetal over-exposure to the maternal GC, resulting in the HPA axis growth inhibition and the serum glucose and lipid metabolism changes. Meanwhile, the IUGR HPA axis showed low based activity and high stress sensitivity, as well as the GC-dependent change of the serum glucose and lipid metabolism phenotype. Furthermore, PCE could inhibit the steroidogenic factor 1 (SF-1), steroidogenic acute regulation protein (StAR) and cytochrome P450 cholesterol side chain cleavage (P450scc) of fetal adrenal steroidogenesis, and change their epigenetic modification. As a result, we propose the HPA axis related "neuroendocrine metabolism programming" mechanism induced by PCE, which could lead to the offspring with high risk of developing metabolic syndrome. And, the inhibition of fetal adrenal steroid synthesis function caused by PCE-induced fetal over-exposure to the maternal GC may be an important mechanism.Literature reported that the role of GC not only depends on the level of GC in the local organizations or circulation, and also is related to the GC metabolic enzymes activity of the 11 beta hydroxy steroid dehydrogenase (11β-HSDs) system (including type 1 and type 2 isoforms) in fetal tissues, 11β-HSD1 reductively activated GC and 11β-HSD2 oxidative inactivated GC. Meanwhile, corticoid receptor (CR) are ligand-dependent nuclear transcriptional factors that comprises the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR). There are literatures reported that GC has higher affinity with MR, and low levels of GC would bind with MR firstly and only a high level of GCs could bind to GR after the MR was completely occupied. Many studies showed that GC/CR could induce 11β-HSD1 expression and suppress 11β-HSD2 expression, and the change of 11β-HSDs/CR system expression could cause viscera dysplasia. CCAAT/enhancer-binding proteins (C/EBPs) family act as one of the important transcription factors in coordinating with 11β-HSDs/CR to regulate the downstream gene expressions, which include C/EBPa and C/EBPβ.Insulin-like growth factor 1 (IGF1) signaling pathway is the core of endocrine regulation system, participating in the proliferation, differentiation and metabolism process of adrenal gland cells in different periods before and after birth. Numerous studies have shown that the IGF1 is closely associated with fetal growth and development, and the spontaneous lack of IGF1 gene will lead to IUGR in human. Although the body’s serum IGF1 mainly comes from the liver, adrenal glands could express IGF1 gene by autocrine or paracrine. The study found that IGF1 and its receptor IGF1R are widely expressed in adrenal cortex, and could modulate the adrenal local SF-1 expression and related steroid synthetase expression to promote the steroid synthesis of adrenal through phosphorylating the PI3K/Akt pathway. The above studies suggest that IGF 1 signal pathway may play important role in adrenal steroid synthesis function. The research suggest that high GC level can inhibit the IGF1 expression in a variety of tissues or cells, and the C/EBP{ knockout in mice liver could lead to the circulation IGF1 levels decreased and C/EBPa also inhibits the IGF1R gene expression. These studies suggest that GC-activation system (11β-HSDs/CR/C/EBPs) might get involved in IGF1 related adrenal intrauterine programming mechanism of PCE offspring.Environmental factors (such as excess nutrients and high stress) can aggravate the viscera developmental toxicity changes in offspring caused by adverse environment during pregnancy, which can increase the risk of adult metabolic syndrome and related disease. Basing on the above, we propose a series of questions as follow:May caffeine induced fetal over-exposure to maternal GC, as well as the consequent change of GC activation system and peripheral IGF 1 signaling pathway result in abnormal morphogenesis and inhibited functional differentiation of adrenal in fetus? Is there any functional change of adrenal steroid hormone synthesis in adulthood for these IUGR offspring with impaired adrenal development when experiencing normal diet after birth? Is there any underlying intrauterine programming mechanism for the changes? Furthermore, could high-fat diet/chronic stimulation induce the GC related metabolic disorders and the final development of diabetes? These questions are of great interest and significance to be elucidated, yet without relevant reports.Therefore, the present study firstly aimed to investigate the effects of PCE on adrenal morphological and functional differentiation in IUGR fetal rats in vivo, and combine with the in vitro experiments to address the roles of GC exposure, adrenal GC activation system and IGF1 signaling pathway in regulation of adrenal function development from molecular aspect. Secondly, by observing the growth and development condition and adrenal function change in adult offspring rats, we expect to verify that adrenal gland development exists intrauterine programming in IUGR offspring induced by PCE. Finally, we expect to verify that PCE induced IUGR offspring show the increased risk of diabetes and adrenal dysfunction after birth via observing the adrenal steroid synthesis and glucose metabolism index change in adult rats under the high-fat diet/chronic stimulation.PART ONEPrenatal caffeine exposure-induced adrenal function developmental abnormality and its mechanism in fetal ratsObjective:To investigate the effects of prenatal caffeine exposure on the serum CORT and IGF1 concentrations, as well as adrenal tissue morphology, steroidogenesis, IGF1 signaling pathway, and GC-activation system changes in vivo, and to confirm the fetal adrenal dysplasia and "GC-IGF1 axis" intrauterine programming phenomenon caused by PCE.Methods:Divide wistar pregnant rats randomly into three groups, control group, small and high dose of PCE groups. From gestational day 9 (GD 9) to GD 20, PCE pregnant rats were respectively administered 30 and 120 mg/kg of caffeine per day by the lavage to establish stable IUGR rat models. The control group rats received the same volume of distilled water. On GD20, the pregnant rats were sacrificed by isoflurane anesthesia and the live fetuses were quickly removed to weigh and distinguish gender, as well as IUGR rates were also calculated. Serum IGF1 and corticosterone (CORT) levels were measured by enzyme-linked immune sorbent assay (ELISA) kit, as well as the adrenal CORT. Hematoxylin-eosin (H&E) staining and transmission electron microscope (TEM) were applied to the adrenal histopathological and cytopathological examination, as well as immunohistochemistry (IHC) was employed to test the Ki67 expression of fetal adrenal. Real-time quantitative PCR was used to quantify fetal adrenal mRNA expressions of genes, including SF-1, StAR, P450scc,3β-hydroxysteroid dehydrogenase (3β-HSD), steroid 21-hydroxylase (P450c21), steroid 11β-hydroxylase (P450c11), IGF1 signaling pathway (IGF1, IGF1R and AKT1), GC metabolic activation system (11β-HSD1,11β-HSD2, MR, GR, C/EBPa, C/EBPβ).Results:① Fetal rats weight and IUGR rates:Compared with control, the mean bodyweights of both male and female fetuses in caffeine group were dose-dependent lower than control groups while corresponding IUGR rates were increased with dose-dependent way (P<0.05, P<0.01). Meanwhile, the male and female fetal IUGR rates in high dose of caffeine groups reached to 93.7% and 97.4% (P<0.01), respectively. ②Serum caffeine concentrations: Fetal blood caffeine concentration in high doses of PCE group increases, accounted for 59.8% of maternal blood caffeine concentration. ③Fetal adrenal morphology and cell proliferation: when compared with control, the cytoplasmic swelling deformation were observed in the male fetus adrenal cortex, and its entire cross-sectional area deceased in high-dose PCE group (P<0.01). IHC result showed that the number of Ki67-stained nuclei was reduced in male fetal adrenal cortical cells compared with the control (P<0.01). TEM results revealed that, in male adrenal cortex cells from high-dose PCE group, the mitochondrial tubular cristae structure were disordered. The PCE female fetal rats had the similar results.④Adrenal steroid synthesis function:When compared with control groups, the mRNA expression levels of SF-1,3β-HSD, P450c21 and P450c11 decreased as well as SF-1 and P450c11 had a dose-dependent way in male PCE fetal rats (P<0.05, P<0.01). For female fetal rats, the mRNA expression levels of StAR,3β-HSD, P450c21 and P450c11 decreased with StAR and P450c21 had a dose-dependent way (P<0.05, P<0.01). Both male and female fetal adrenal local CORT were decreased (P<0.05). ⑤IGF1 signaling pathway change of fetal rats:When compared to control, both male and female fetal serum IGF1 concentrations were basically decreased or had decline tendency in the PCE groups (P<0.05, P<0.01). Furthermore, male and female fetal IGF1 signaling pathway (IGF1, IGF1R, AKT1) in PCE groups were both decreased (P<0.05, P<0.01), presenting a dose-dependent way. ⑥Fetal serum CORT level and adrenal GC-metabolic system:When compared to control, the serum CORT level of male fetal increased with a dose-dependent way while it was increased only in low-dose PCE group for female fetal rats (P<0.05, P<0.01). Besides, for male fetal rats of PCE groups, the adrenal mRNA expression levels of 11β-HSD1, 11β-HSD1/11β-HSD2 expression ratio, MR, GR, C/EBPa and C/EBPa/C/EBPβ expression ratio increased or had rising tendency, as well as the mRNA expression of 11β-HSD2 and C/EBPβ were decreased with a dose-dependent way (P=0.08, P=0.06, P<0.05, P<0.01). For female fetal rats of PCE groups, only 11β-HSD1/11β-HSD2 expression ratio, C/EBPa/C/EBPβ expression ratio and C/EBPa mRNA expression were significantly increased in high dose PCE group (P<0.01), but C/EBPβ expression showed a decline tendency (P=0.06).Conclusion:Prenatal caffeine exposure could cause fetal rat adrenal gland function dysplasia. The activation of adrenal local GC activation system (11β-HSDs/CR/CEBPs) during intrauterine period caused by fetal over-exposure to the maternal GC may be involved in mediating the inhibition of circulating IGF1 level and adrenal IGF1 signaling pathway (GC-IGF1 axis programming) induced by PCE, and result in abnormal cell proliferation and differentiation in fetal rat adrenal.PART TWOCortisol exposure induced steroid hormones synthesis function suppression and its potential mechanism in human fetal adrenal cellsObjective:To investigate the effects of different cortisol concentrations on GC activation system, IGF1 signaling pathways and steroidogenic function in fetal adrenal NCI-H295A cells in vitro, and to explore the specific action mechanism of "GC-IGF1 axis" in fetal adrenal cells function developmental disorders caused by cortisol.Methods:Conventional methods to cultivate the human fetal adrenal cortical cell line-NCI-H295A cell line and to establish the cell proliferation model. The human fetal adrenal cortex cells were dealt with cortisol with different concentrations (0,150,300,600 and 1200 nM) for 48 h, and with 300 and 1200 nM of cortisol for different times (12,24, and 48 h). Furthermore, cortisol (300,1200 nM) and Mifepristone (10 nM) were also used together to treat the NCI-H295A cell line. Cell viability was evaluated by MTS assay, as well as the levels of cortisol in the NCI-H295A cells were measured by ELISA. Western blotting and PCR were used to detect the protein and mRNA expression of genes, including StAR, P450scc, "GC-IGF1 axis" (11β-HSD1, 11β-HSD2, MR, GR, C/EBPa, C/EBPp, IGF1 and IGF1R). At the same time, using confocal laser scanning microscope (CLSM) to observe the nuclear translocation change of GR in adrenal gland cell after cortisol treatment.Results:(DCell proliferation test:Compared with control, cortisol (0,150,300,600 and 1200 nM) treatment for 2 days had no significant effect on cell viability, while treatment for 3 d and 5 d had no significant inhibition on number of cells. ②Time-effect relationship of steroid hormones synthesis:Compared with control, after the NCI-H295A cells were dealt with small doses cortisol (300 nM) for 12,24 and 48 h, the GC within cells increased or presented an increase trend (P<0.05), and the results for 48 h were more significantly. Besides, after dealt with high doses cortisol (1200 nM) for 12,24 and 48 h, the GC within cells were decreased (P<0.05), and the results for 12 and 48 h were both more significantly. ③ Dose-dependent relationship of steroid hormones synthesis:Compared with control, after dealt with high doses of cortisol, the GC within NCI-H295A cells firstly present increase and then decrease, which specific showed increased in 300 nM and significantly decreased in 1200 nM cortisol (P<0.05, P<0.01). Although, the corresponding steroid synthetase (StAR and P450scc) are dose-dependent decreased (P0.05). ④GC-activation system and IGF1 signaling pathway changes:Compared with control, different concentrations of cortisol treatment could increase the expression of 11βHSD1、CR、CEBPa in NCI-H295A cells, decrease the expression of 11βHSD2, CEBPβ, IGF1 and IGF1R in a dose-dependent way, and the effect of high-dose cortisol was the most significantly (P<0.05, P<0.01). Meanwhile, we found that protein level results were consistent with the results of genetic level. However, the effects of small dose of cortisol (150 and 300 nM) on GR and CEBPβ gene expression were opposite to the large dose. ⑤GR participate in adrenal function inhibition caused by cortisol: When compared with control, after the NCI-H295A cells were dealt with 1200 nM cortisol for 48 h, the gene expression of StAR and P450scc were both decreased, and the GR antagonist mifepristone can obviously reverse the effect (P<0.05, P<0.01). However, the treatment with 300 nM cortisol and mifepristone in NCI-H295A cells had no significant effect. ⑥GR participate in adrenal GC-IGF1 axis changes caused by cortisol:Compared with control group, the gene expressions of 11βHSD1、CR、CEBPα were enhanced, and the gene expressions of 11βHSD2、CEBPβ、IGF1 and IGF1R were decreased; as well as the GR antagonist mifepristone can obviously reverse the effect (P<0.05, P<0.01). However, the treatment with 300 nM cortisol and mifepristone in NCI-H295A cells had no such effect. ⑦GR nuclear translocation mediated the effects of cortisol on NCI-H295A cells:In NCI-H295A cells of control and GR antagonist mifepristone group, GR distributed in both cytoplasm and nuclei, and when dealt with 1200 nM cortisol, GR were mainly distributed in the nucleus. However, treatment with mifepristone made the GR distributed in both cytoplasm and nuclei again.Conclusion:The activation of GC system metabolism in adrenal cells induced by cortisol could inhibit the IGF1 signaling pathway expressions. This "GC-IGF1 axis" could further inhibit the expression of steroid synthetase in fetal adrenal gland and reduce the adrenal function. Furthermore, the GR nuclear translocation mediated the regulation to "GC-IGF1 axis" in adrenal gland cells induced by cortisol.PART THREEPrenatal caffeine exposure-induced changes of adrenal foundation and its intrauterine programming mechanismObjective:On the previous basis that PCE could cause the structure and function developmental anomalies of fetal adrenal, we observe the changes of the body weights, serum phenotypes, adrenal steroidogenic enzyme system, IGF1 signaling pathway, and GC-activation system in prenatal caffeine exposure-induced IUGR offspring at different time after birth fed by normal diet. So clarify the programming alteration of adrenal steroid hormone synthesis function in IUGR offspring induced by PCE.Methods:Wistar pregnant rats were randomly divided into two groups, control group and caffeine group, and the treatment was the same as the first part. All the pregnant rats were allowed to deliver spontaneously at term, when it was postnatal day (PD) 1 of the fetal rat after birth, screen out pregnant rats with litter size between 10 and 16 fetal rats, adjust the young rats to 10 per litter and try to balance the gender ratio of male and female fetal rats. After weaned at postnatal week (PW) 4, male and female offspring were separated. Then, all the offspring were fed by standard laboratory diet until PW24, and the weights of offspring were recorded every 4 weeks after birth, as well as the weights gain rates were also calculated. At the same time, the offspring rats were sacrificed by isoflurane anesthesia to collect blood and adrenal tissue according to the different mature point time (PD1, PD7, PD35 and PD168) after growth. At PD100 the blood samples were collected through tail vein blood and used to test the blood phenotype changes. In order to obtain enough samples, the average of 4,3 and 2 littermates from each dam were decapitated at PD1, PD7 and PD35 respectively, and these serum and adrenal samples of littermates were pooled to count as one independent sample for subsequent detection. The adrenal histopathological and cytopathological change was based on H&E, and IHC was employed to detect the Ki67 expression. ELISA kit was used to detect the serum IGF1, CORT, and adrenal CORT. Furthermore, real-time PCR was used to determine the mRNA expressions of steroidogenic enzymes, GC-activation system and IGF1 signaling pathway.Results:①Body weight and its gain rate in offspring:Compared with their own control groups, the male and female offspring rats in the PCE group showed significantly low body weights at PW 1 (P<0.01). After weaning, body weights of male offspring in PCE group were lower than control at PW 12, PW 16, PW 20 and PW 24, but the gain rates at all time points showed significant increase (P<0.05, P<0.01). Besides, the female offspring rats showed significantly decreased body weights from PW 8 to PW 24, and increased gain rates at all time points (P<0.05, P<0.01). ②Adrenal pathological and cell proliferation changes:There were no significant changes in the morphology of adult adrenal between control and PCE groups. The entire cross-sectional area and Ki 67-stained nuclei of adult adrenal cells showed no obvious change. ③Adrenal steroid synthesis function:Compared with control group, adrenal steroid synthetase mRNA expression of StAR, P450scc and 3(3-HSD in PCE male offspring significantly decreased or showed the decreased trend at all time points (P<0.05, P<0.01); and the P450c21 and P450c11 expression decreased or showed the decreased trend from PD 1 to PD 35 (P=0.06, P<0.01), then gradually increased and surpassed the control group, as well as transcription factors SF-1 only significantly decreased at PD 1 after birth (P<0.01). For PCE female offspring, the adrenal steroid synthetase mRNA expression (including StAR, P450scc,3β-HSD, P450c21 and P450c11) decreased or showed the decreased trend (P=0.06, P<0.05, P<0.01) at all time points after birth. Furthermore, ELISA results showed that the male and female adrenal CORT levels in the PCE adult offspring were 93.1% and 78.1% of that in control groups. ④Serum CORT and IGF1 correlation change: Compared with control, the serum CORT level of PCE male offspring rats increased from PD 1 to PD 35, decreased at PD 60, and gradually were close to the control groups after that (P<0.05, P<0.01), and the corresponding serum IGF1 concentrations significantly reduced from PD 1 to PD 35, then gradually increased and surpassed the control group (P=0.09, P<0.05, P<0.01). Moreover, there was significant negative correlation between serum CORT and IGF1 levels (P<0.05). For PCE female offspring, the serum CORT level increased at PD 1 and decreased at PD 100 and PD 168, the corresponding serum IGF1 concentrations significantly reduced at PD 1 and PD 168 (P<0.05, P<0.01), as well as there was no significant correlation between serum CORT and IGF1 levels. ⑤Adrenal GC-activation system and IGF1 signal pathway:Compared with the control groups, the levels of 11β-HSD2, MR and C/EBPβ expression increased, 11β-HSD1/11β-HSD2 and C/EBPα/C/EBPβ expression ratio decreased for the male offspring in PCE groups rats (P<0.01). Meanwhile, the expression of key genes (IGF1, IGF1R, AKT1) of the IGF1 signaling pathway increased (P<0.01). Meanwhile, for the female offspring in PCE groups rats, the levels of 11β-HSD2 and C/EBPβ expression decreased, CR expression and C/EBPα/C/EBPβ expression ratio increased in the adrenal (P<0.05, P<0.01). And there is only IGF1R expression increased on the IGF1 pathways (P<0.05).Conclusion:In the present study, we demonstrated that PCE caused adrenal function developmental abnormality in offspring rats, which may be related to a "two-programming mechanisms". The intrauterine lower-functional programming of adrenal steroidogenesis is "the first programming", which result in fetal adrenal dysplasia; on the other hand, GC-activation system-mediated GC-IGF1 axis programming is "the second programming" which is involved in prenatal adrenal structural and functional abnormality and postnatal compensatory enhancement of adrenal structure and function induced by the catch-up growth.PART FOURThe high sensitivity of adrenal function and insulin resistance in prenatal caffeine exposure-induced IUGR offspringObjective:After confirmed the two kinds of mechanism programming of adrenal function dysplasia in PCE offspring rats, by combining high fat diet (to mimic the high nutritional status) with chronic stress (to mimic the high social pressure) models, and further observing the change of adrenal steroid synthesis function and glycometabolism in the caffeine-induced IUGR offspring under chronic stress fed by high-fat diet after birth, to confirm the phenomenon that IUGR adult offspring susceptible to metabolic disease and explore the mechanism.Methods:Wistar pregnant rats were randomly divided into two groups, control group and caffeine group, and the treatment was the same as the first part. All the pregnant rats were allowed to deliver spontaneously at term, when it was postnatal day (PD) 1 of the fetal rat after birth, screen out pregnant rats with litter size between 10 and 16 fetal rats, adjust the young rats to 10 per litter and try to balance the gender ratio of male and female fetal rats. All the offspring rats were fed by high-fat diet (HFD) (containing 89.5% of corn flour,10% of lard and 0.5% of cholesterol) from PW4, and the weights of offspring were recorded every 4 weeks after birth, and the weights gain rates were also calculated. On PW21, randomly selected 10 rats from the control group and PCE group and dealt as the first batch groups, which were exposed to the unpredictable chronic stress (UCS) procedure for 21 days. UCS including that:food deprivation for 24 h; water deprivation for 24 h; tail pinch for 5 min (with 2 cm distance to tail); hot stress at 45℃ for 5 min; swimming at 4-8℃ cold water for 4 min, and they were dried with towel; then reversed day and night cycles; followed by the social isolation (only one rat per cage) for 24 h. Each stressor was administered randomly at an interval of 7 days and given totally 3 times within 3 weeks. On PW24, oral glucose tolerance test (OGTT) was performed with these rats. At the last day of stress after 12 h fasting, all rats swim at 4-8℃ cold water for 4 min and were towel dried. The rats were anesthetized with isoflurane and decapitated to collect the blood and adrenal samples one hour after swimming, and saved as the samples after chronic stimulation. The second batch of offspring was also performed with OGTT without the UCS, followed by the same deal as the first batch groups. Biochemical methods and ELISA techniques were used to detect the serum glucose and CORT concentrations, and radioimmunoassay was used to detect serum adrenocorticotropic hormone (ACTH) and insulin levels. Real-time PCR was performed to determine the mRNA expressions of steroidogenic enzymes system, GC-activation system and IGF1 signaling pathway.Results: ①Body weight and its gain rates:Compared with control, PCE resulted in decreased body weights of both male and female offspring at PW1 (P<0.01). After weaning fed by HFD, the body weights of male offspring rats in PCE group were lower than the control from PW4 to PW20, but the corresponding body weight growth rate were significant higher than the control from PW16 to PW24 (P<0.01, P<0.05). For the female offspring rats, the body weights decreased at PW4 and PW16 in PCE group, and the gain rates increased at all time points (P<0.01, P<0.05). ②Serum ACTH and CORT levels:Compared with control, ACTH level in female PCE group was decreased (P<0.05), and the CORT level in female and male PCE group were decreased or presented a decreasing trend before stress (P=0.09, P<0.01). While under UCS, the ACTH and CORT levels of female in PCE group were increased (P<0.01) (the male PCE offspring showed an increasing trend). The corresponding gain rate of ACTH and CORT were both increased in male and female offspring (P<0.01). ③ Adrenal steroidogenic enzyme system changes:Compared with control group before UCS, the mRNA expression of adrenal StAR, P450scc,3β-HSD, P450c11 were all decreased in male PCE group (P<0.01); for the female PCE group, the mRNA expression of StAR and P450c11 were decreased while P450c21 was increased (P<0.05, P<0.01). After the UCS, the mRNA expression of adrenal StAR, P450scc and P450c11 were all increased in male PCE group (P<0.05, P<0.01); as well as the mRNA expression of SF-1, P450scc and P450c11 were increased in the PCE group (P<0.05, P<0.01). ④hange of GC-IGF1 axis:Compared with control, in male PCE group before UCS, the expression of 11β-HSD2, IGF1, IGF1R and AKT1 were markedly increased relative to the control (P<0.05, P<0.01), and expression of 11β-HSD1, MR and 11β-HSD1/11β-HSD2 expression ratio were decreased (P<0.05, P<0.01); after UCS, the expression of 11β-HSD2, IGF1 and IGF1R decreased (P<0.05, P<0.01), and the expression of 11β-HSD1, MR and 11β-HSD1/11β-HSD2 expression ratio were increased (P<0.05, P<0.01). Accordingly for female PCE offspring, before UCS the expression of MR, IGF1, AKT1 and 11β-HSD1/11β-HSD2 expression ratio were increased (P<0.05, P<0.01); after UCS,11β-HSD1, MR expression and 11β-HSD1/11β-HSD2 expression ratio were increased (P<0.05), and the IGF1 signal pathway showed inhibition. ⑤ Serum glucose, insulin and quantitative insulin sensitivity check index (QUICKI):Compared with the control group, before UCS the level of serum glucose in female were significantly increased and the insulin level decreased (P<0.01), and in the male PCE group there were no obvious changes. After UCS, serum glucose and insulin in male PCE group were significantly increased while the QUICKI were decreased (P<0.05, P<0.01). ⑦OGTT glycometabolism changes: Compared with control, under the glucose challenge before UCS, the relative serum glucose and the area under the curve (AUC) of PCE male offspring had no change, the serum insulin level at 30,60 and 90 min as well as the AUC all increased (P<0.05, P<0.01); and after UCS, the serum glucose level continued to decline, presented by the serum glucose at 30,60 and 90 min as well as AUC all lower than the control groups (P<0.05, P<0.01), while there was no change in the serum insulin levels. However, in female, relative serum glucose, insulin and AUC were not changed.Conclusion:PCE could cause adrenal developmental abnormality in offspring rats under UCS fed by HFD after birth, mainly presented by adrenal high sensitivity and abnormal serum GC levels, which may be resulted from intrauterine "two-programming" changes of adrenal. Furthermore, the abnormal serum GC level caused by adrenal high sensitivity could reduce the insulin sensitivity index and further induce diabetic-like changes for IUGR offspring.Summary:1. In the present study, PCE could inhibit fetal adrenal corticosterone synthesis. This activation status of GC-activation system might be involved in that circulating high maternal GC inhibited the adrenal IGF1 signaling pathway, and resulted in the abnormal cell proliferation and functional differentiation in fetal adrenal.2. In cell and molecular level, cortisol could directly activate the GC-activation system, and inhibit the IGF1 signaling pathway, which could lead to fetal adrenal steroid synthesis inhibition. The GR nuclear translocation after activation may mediate the steroid synthesis function inhibition of fetal adrenal cell.3. PCE induced adrenal function inhibition could last until adult offspring rats, obviously in female offspring fed by normal diet, which may have intrauterine programming effect. Meanwhile, the male offspring showed compensatory increase in adrenal function, which caused by the "GC-IGF1 axis" programming.4. PCE induced IUGR showed adrenal dysfunction under HFD/UCS after birth, and the GC-IGF1 axis could involve in the high level of adrenal function to maintain the high GC synthetic function of adrenal, which lead to insulin resistance and further induce diabetic-like changes for IUGR offspring. |
PDF Full Text Request