Glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis programming mediated hepatic lipid-metabolic in offspring caused by prenatal ethanol exposure

Glucocorticoids and intrauterine programming of nonalcoholic fatty liver disease

Accumulating epidemiological and experimental evidence indicates that nonalcoholic fatty liver disease (NAFLD) has an intrauterine origin. Fetuses exposed to adverse prenatal environments (e.g., maternal malnutrition and xenobiotic exposure) are more susceptible to developing NAFLD after birth. Glucocorticoids are crucial triggers of the developmental programming of fetal-origin diseases. Adverse intrauterine environments often lead to fetal overexposure to maternally derived glucocorticoids, which can program fetal hepatic lipid metabolism through epigenetic modifications. Adverse intrauterine environments program the offspring's glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis, which contributes to postnatal catch-up growth and disturbs glucose and lipid metabolism. These glucocorticoid-driven programming alterations increase susceptibility to NAFLD in the offspring. Notably, after delivery, offspring often face an environment distinct from their in utero life. The mismatch between the intrauterine and postnatal environments can serve as a postnatal hit that further disturbs the programmed endocrine axes, accelerating the onset of NAFLD. In this review, we summarize the current epidemiological and experimental evidence demonstrating that NAFLD has an intrauterine origin and discuss the underlying intrauterine programming mechanisms, focusing on the role of overexposure to maternally derived glucocorticoids. We also briefly discuss potential early life interventions that may be beneficial against fetal-originated NAFLD.

Prenatal ethanol exposure and changes in fetal neuroendocrine metabolic programming

Prenatal ethanol exposure (PEE) (mainly through maternal alcohol consumption) has become widespread. However, studies suggest that it can cause intrauterine growth retardation (IUGR) and multi-organ developmental toxicity in offspring, and susceptibility to various chronic diseases (such as neuropsychiatric diseases, metabolic syndrome, and related diseases) in adults. Through ethanol's direct effects and its indirect effects mediated by maternal-derived glucocorticoids, PEE alters epigenetic modifications and organ developmental programming during fetal development, which damages the offspring health and increases susceptibility to various chronic diseases after birth. Ethanol directly leads to the developmental toxicity of multiple tissues and organs in many ways. Regarding maternal-derived glucocorticoid-mediated IUGR, developmental programming, and susceptibility to multiple conditions after birth, ethanol induces programmed changes in the neuroendocrine axes of offspring, such as the hypothalamus-pituitary-adrenal (HPA) and glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axes. In addition, the differences in ethanol metabolic enzymes, placental glucocorticoid barrier function, and the sensitivity to glucocorticoids in various tissues and organs mediate the severity and sex differences in the developmental toxicity of ethanol exposure during pregnancy. Offspring exposed to ethanol during pregnancy have a "thrifty phenotype" in the fetal period, and show "catch-up growth" in the case of abundant nutrition after birth; when encountering adverse environments, these offspring are more likely to develop diseases. Here, we review the developmental toxicity, functional alterations in multiple organs, and neuroendocrine metabolic programming mechanisms induced by PEE based on our research and that of other investigators. This should provide new perspectives for the effective prevention and treatment of ethanol developmental toxicity and the early prevention of related fetal-originated diseases.

Developmental toxicity and programming alterations of multiple organs in offspring induced by medication during pregnancy

Medication during pregnancy is widespread, but there are few reports on its fetal safety. Recent studies suggest that medication during pregnancy can affect fetal morphological and functional development through multiple pathways, multiple organs, and multiple targets. Its mechanisms involve direct ways such as oxidative stress, epigenetic modification, and metabolic activation, and it may also be indirectly caused by placental dysfunction. Further studies have found that medication during pregnancy may also indirectly lead to multi-organ developmental programming, functional homeostasis changes, and susceptibility to related diseases in offspring by inducing fetal intrauterine exposure to too high or too low levels of maternal-derived glucocorticoids. The organ developmental toxicity and programming alterations caused by medication during pregnancy may also have gender differences and multi-generational genetic effects mediated by abnormal epigenetic modification. Combined with the latest research results of our laboratory, this paper reviews the latest research progress on the developmental toxicity and functional programming alterations of multiple organs in offspring induced by medication during pregnancy, which can provide a theoretical and experimental basis for rational medication during pregnancy and effective prevention and treatment of drug-related multiple fetal-originated diseases.

MiR-133a-3p/Sirt1 epigenetic programming mediates hypercholesterolemia susceptibility in female offspring induced by prenatal dexamethasone exposure

Mounting evidence indicates that adverse intrauterine conditions increase offspring's hypercholesterolemia susceptibility in adulthood. This study aimed to confirm prenatal dexamethasone exposure (PDE)-induced hypercholesterolemia susceptibility in female adult offspring rats, and elucidate its intrauterine programming mechanism. Pregnant Wistar rats were injected with dexamethasone subcutaneously (0, 0.1 and 0.2 mg/kg·d) from gestational day (GD) 9 to 20. Serum and liver of the female offspring were collected at GD21 and postnatal week (PW) 12 and 28. PDE offspring showed elevated serum total cholesterol (TCH) levels and a cholesterol phenotype of high cardiovascular disease risk at PW12 and PW28. The histone acetylation levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) and its expression were consistently increased in the PDE offspring both in utero and after birth. Moreover, PDE promoted glucocorticoid receptor (GR) nuclear translocation and miR-133a-3p expression and inhibited sirtuin-1 (Sirt1) expression in the fetal liver. In vitro, dexamethasone increased intracellular and supernatant TCH levels and miR-133a-3p expression, decreased SIRT1 expression, and promoted HMGCR histone acetylation and expression in bone marrow mesenchymal stem cells (BMSCs) hepatoid differentiated cells and HepG2 cell line. GR siRNA, miR-133a-3p inhibitor or SIRT1 overexpression reversed dexamethasone-induced downstream molecular and phenotypic changes. Furthermore, elevated TCH levels in umbilical cord blood and increased HMGCR expression in peripheral blood mononuclear cells (PBMCs) were observed in human female neonates who had received dexamethasone treatment during pregnancy. In conclusion, PDE can cause persistent enhancement of hepatic cholesterol synthesis function before and after birth through GR/miR-133a-3p/Sirt1 pathway, eventually leading to increased hypercholesterolemia susceptibility in female offspring rats.

11β-hydroxysteroid dehydrogenases and biomarkers in fetal development

It is known that basal glucocorticoid levels in utero are essential for regulating fetal development and maturation, and determine the fate of later life. Recently, more and more studies suggest that adverse prenatal environments may cause abnormal maternal glucocorticoid levels in utero. 11β-hydroxysteroid dehydrogenases (11β-HSDs) are widely distributed in the target organs of glucocorticoids (GCs) and mineralocorticoids. 11β-HSDs is involved in fetal physiological and pathological development by activating or inactivating GCs. Prenatal adverse environments (including exogenous and maternal environments) can affect the expression and activity of 11β-HSDs in the placenta and fetus via multiple pathways. It induces abnormal local glucocorticoid levels in fetal multiple tissues, fetal developmental programming and homeostasis changes, and the susceptibility to various diseases after birth. We also discuss the interventions of 11β-HSDs inhibitors on fetal developmental programming and susceptibility to multiple diseases. Finally, we propose that 11β-HSD2 can be used as a molecular target for fetal developmental toxicity, while 11β-HSD1 can be regarded as an intervention target to prevent fetal-originated diseases. This review will provide a theoretical basis for the early prevention and treatment of fetal-originated diseases.

Prenatal ethanol exposure induces dynamic changes of expression and activity of hepatic cytochrome P450 isoforms in male rat offspring

This study aimed at determining the effect of prenatal ethanol exposure (PEE) on the expression and activity of cytochrome P450 (CYP) isozymes at different life stages of male rat offspring. Pregnant Wistar rats were administered with ethanol (4 g/kg/d) intragastrically from gestational day (GD) 9-20. Male offspring's gene and activity of CYP isozymes were analyzed on GD 20 (only expression), postnatal day (PD) 84 and 196. Using aniline as probe, we compared the enzyme kinetics of hepatic CYP2E1 between two groups. Expression of CYP isozymes was examined in rat primary hepatocytes and human hepatic cell lines treated with ethanol or/and glucocorticoid. Gene level of Cyp1a2, 2b1, 2d1, 2e1, 3a1 and aryl hydrocarbon receptor were increased in PEE group on GD 20 and PD 84 and Cyp2e1 still exhibited an increasing trend on PD 196 compared with the control. PEE inhibited CYP2D1 and 2E1 activities in male offspring on PD 84. CYP activities in two groups became the same level on PD 196. PEE induced an opposite change in gene and protein level of hepatic CYP2E1 before and after birth. In consistent with lower protein level, aniline metabolism in PEE was weaker in liver microsome. Both single and combined use of ethanol or/and glucocorticoid increased CYPs expression in vitro. In conclusion, PEE programmed a higher gene and lower protein level of CYPs in male offspring, which dwindled with age. Impairment of protein levels and enzyme activities of CYPs may affect individual metabolism of endogenous and exogenous substances in early adulthood.

Intergenerational genetic programming mechanism and sex differences of the adrenal corticosterone synthesis dysfunction in offspring induced by prenatal ethanol exposure

We previously found that prenatal ethanol exposure (PEE) induced adrenal dysplasia in offspring, which was related to intrauterine maternal glucocorticoid overexposure. This study investigated the intergenerational genetic effect and sex differences of PEE-induced changes in the synthetic function of adrenal corticosterone in offspring, and to clarify the intrauterine origin programming mechanism. Wistar pregnant rats were gavaged with ethanol (4 g/kg bw/d) from gestation day (GD) 9-20, and F1 generation was born naturally. The F1 generation female rats in the PEE group were mated with normal male rats to produce F2 generation. Serum and adrenal glands of fetal rats and F1/F2 adult rats were collected at GD20 and postnatal week 28. PEE increased the serum corticosterone level, while diminishing the expression of adrenal steroid synthases of fetal rats. Moreover, PEE enhanced the mRNA expression of GR and HDAC1, but inhibited the mRNA expression of SF1 and reduced the H3K9ac level of P450scc in the fetal adrenal gland. In PEE adult offspring of F1 and F2 generation the serum corticosterone level, the H3K9ac level of P450scc and its expression were decreased in males but were increased in females. In NCI-H295R cells, cortisol reduced the production of endogenous cortisol, down-regulated SF1, and up-regulated HDAC1 expression by activating GR, and decreased H3K9ac level and expression of P450scc. In conclusion, PEE could induce adrenal dysplasia in offspring with sex differences and intergenerational genetic effects, and the adrenal insufficiency in male offspring was related to the induction of low functional genetic programming of P450scc by intrauterine high corticosterone through the GR/SF1/HDAC1 pathway.

Prenatal ethanol exposure increases maternal bile acids through placental transport pathway

High maternal serum bile acid level is common and sometimes harmful to the gravida. This study aimed to confirm the bile acid phenotypic change caused by prenatal ethanol exposure (PEE) and elucidate its placental mechanism. Pregnant Wistar rats were administered intragastrically with ethanol 4 g/kg⋅d from gestational day 9-20. Total bile acids (TBA) were detected in maternal, fetal serum and placental tissues, increasing significantly in the serum but no significant change in the placental tissues. Meta-analysis was performed and verified the efficacy of the PEE-induced model based on published data from several relevant studies. Mining of microarray data from human and rat placental sources identified the involvement of bile acid metabolism and its significant genes, which were verified by RT-qPCR and western blotting on tissues and treated BeWo cells with the administration of FXR/PXR siRNAs or FXR/PXR agonists. Our examination, consistent with microarray data and wet experiments, showed that organic anion transporter polypeptide-related protein 2B1 (Oatp2b1), multidrug resistance-associated proteins 3 (Mrp3) and breast cancer resistance protein (Bcrp) expression were increased, while nuclear receptor farnesoid X receptor (Fxr) was decreased but pregnane X receptor (Pxr) was increased. Furthermore, the interventional experiments confirmed that FXR regulated Bcrp while PXR regulated Oatp2b1 and Mrp3. In summary, PEE could induce high bile acid level in maternal serum and its mechanism is associated with the high expression of BCRP/MRP3/OATP2B1 in the placenta through up-regulating PXR and down-regulating FXR, thereby leading to an excessive bile acid transport to maternal blood via the placenta. Our study provides a novel perspective in terms of placenta, explaining the increased maternal blood bile acids under the toxicity of PEE.

The Placenta as a Target for Alcohol During Pregnancy: The Close Relation with IGFs Signaling Pathway

Alcohol is one of the most consumed drugs in the world, even during pregnancy. Its use is a risk factor for developing adverse outcomes, e.g. fetal death, miscarriage, fetal growth restriction, and premature birth, also resulting in fetal alcohol spectrum disorders. Ethanol metabolism induces an oxidative environment that promotes the oxidation of lipids and proteins, triggers DNA damage, and advocates mitochondrial dysfunction, all of them leading to apoptosis and cellular injury. Several organs are altered due to this harmful behavior, the brain being one of the most affected. Throughout pregnancy, the human placenta is one of the most important organs for women's health and fetal development, as it secretes numerous hormones necessary for a suitable intrauterine environment. However, our understanding of the human placenta is very limited and even more restricted is the knowledge of the impact of toxic substances in its development and fetal growth. So, could ethanol consumption during this period have wounding effects in the placenta, compromising proper fetal organ development? Several studies have demonstrated that alcohol impairs various signaling cascades within G protein-coupled receptors and tyrosine kinase receptors, mainly through its action on insulin and insulin-like growth factor 1 (IGF-1) signaling pathway. This last cascade is involved in cell proliferation, migration, and differentiation and in placentation. This review tries to examine the current knowledge and gaps in our existing understanding of the ethanol effects in insulin/IGFs signaling pathway, which can explain the mechanism to elucidate the adverse actions of ethanol in the maternal-fetal interface of mammals.