Low miR-92a-3p in oocytes mediates the multigenerational and transgenerational inheritance of poor cartilage quality in rat induced by prenatal dexamethasone exposure.

An adverse environment during pregnancy leads to intrauterine programming changes in multiple generations, resulting in the multigenerational inheritance of abnormal phenotype. Here, we reported the multigenerational inheritance of poor articular cartilage quality induced by prenatal dexamethasone exposure (PDE) with 0.2 mg/kg·d dexamethasone from gestational day (GD) 9 to GD20 in Wistar rats and investigated its intrauterine epigenetic programming mechanism. For the F1 female offspring at GD20, we found that the matrix synthesis of cartilage was suppressed, the histone 3 lysine 9 acetylation (H3K9ac) level and mRNA expression of the TGFß signaling pathway were decreased, and the expression of histone deacetylase (HDAC) 2 was increased in the cartilage. Meaningfully, the similar changes were also found in the F1-F3 female adult offspring. Furthermore, PDE decreased the expression of miR-92a-3p in the oocytes of the F1-F2 offspring and in the cartilage of the F1-F3 generations. In vitro, the effect of dexamethasone on chondrocytes revealed that it inhibited the expression of miR-92a-3p through activating and binding glucocorticoid receptor, and reduced the H3K9ac level in the promoter of the TGFß signaling pathway through the increased HDAC2. In conclusion, PDE induces the multigenerational inheritance of poor articular cartilage quality in female adult offspring; the potential mechanism involves the intergenerational effect of low miR-92a-3p expression in oocytes and low functional programming of TGFß signaling pathway induced by decreased H3K9ac level via upregulating HDAC2. This study provides a new perspective to explain the multi-generation inheritance of PDE-induced organ dysplasia in adult offspring.

Activation of α-7 Nicotinic Acetylcholine Receptor Attenuates Cardiac Inflammation Through NLRP3/Caspase-1/IL-18 Pathway.

Activation of α-7 nicotinic acetylcholine receptor (α7nAChR) receptor might induce cardiac inflammation, cardiac remodeling, and dysfunction. In this regard, this study aims to clarify the role and mechanism of α7nAChR in the process of cardiac inflammation and damage. Normal male C57BL/6J and NLRP3-knockout mice were used to evaluate the effect of PHA-543613, a selective agonist of α7nAChR, on cardiac inflammation and possible involvement of NLRP3/Caspase-1/IL-18 using western blotting and ELISA. Activation of α7nAChR using PHA-543613 (NE), at the doses of 0.5 mg/kg and 1 mg/kg, induced cardiac inflammation. In addition, both in vivo and in vitro studies showed higher expression of NLRP3 and higher activation of Caspase-1 and IL-18 after treating animals with NE. On the other hand, we did not observe any significant changes in inflammatory cytokines and cardiac inflammation after administration of NE in NLRP3-knockout mice. It could be concluded that blocking the NLRP3/Caspase-1/IL-18 pathway can simultaneously inhibit the inflammatory response mediated by α7nAChR and it would a novel target for inhibiting cardiac inflammation and remodeling.

Prenatal dexamethasone exposure programs the decreased testosterone synthesis in offspring rats by low level of endogenous glucocorticoids.

Prenatal dexamethasone exposure (PDE) can decrease maternal endogenous glucocorticoid level and induce testicular dysplasia in male offspring rats. In this study we investigated low level endogenous glucocorticoid-mediated testicular dysplasia in PDE offspring and elucidated the intrauterine epigenetic programming mechanisms. Pregnant rats were injected with dexamethasone (0.2 mg·kg-1·d-1, sc) on gestational day (GD) 9-20. The offspring rat blood and testis were collected after euthanasia on GD20, postnatal week (PW) 12 or PW28. We showed that PDE induced abnormal morphology of testis and significantly decreased the expression of testosterone synthesis-related genes as well as testosterone production before and after birth. Meanwhile, serum corticosterone, the expression and histone 3 lysine 14 acetylation (H3K14ac) of testicular insulin-like growth factor 1 (IGF1) were significantly decreased. After the pregnant rats were subjected to chronic stress for 2 weeks (PW10-12), serum corticosterone level was increased in the adult PDE offspring, and the above-mentioned other indicators were also improved. Cultured Leydig cells (TM3) were treated with corticosterone (62.5-500 nM) in vitro. We showed that corticosterone concentration-dependently inhibited glucocorticoid receptor α (GRα) and miR-124-3p expression, increased histone deacetylase 5 (HDAC5) expression, and decreased IGF1 H3K14ac level and the expression of IGF1/steroidogenic acute regulatory protein (StAR), suggesting that corticosterone at lower than physiological level (<500 nM) inhibited testosterone synthesis by reducing H3K14ac and the expression level of IGF1 through GRα/miR-124-3p/HDAC5 pathway. In conclusion, PDE can cause persistent inhibition of testosterone synthesis before and after birth in the offspring rats by low level of endogenous glucocorticoids.

[Effects of curcumol on liver function and fibrosis in rats of nonalcoholic fatty liver disease and its mechanism].

Objective: To investigate the effects and mechanism of curcumol (CC) on liver function and fibrosis in rats of nonalcoholic fatty liver disease (NAFLD). Methods: The rat models of nonalcoholic steatohepatitis (NASH) combined with liver fibrosis were constructed by high-fat diet. Sixty SD rats were randomly divided into blank control group, model group (NASH), NASH + Compound Biejiarangan Troche (CBT) group (positive control group), and NASH + CC groups (25, 50, 100 mg/kg) , 10 rats in each group. The percentage of liver to body weight, and the levels of high density lipoprotein (HDL), triglyceride (TG), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. The liver fibrosis was observed by HE staining. The expressions of α-smooth muscle actin (α-SMA) and positive staining of nuclear factor κB p65 (NF-κB p65) were detected by immunohistochemistry. The expression levels of α-SMA, matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and toll-like receptor-4 (TLR4), transforming growth factor-activated kinase-1 (TAK1), NF-κB p65 and vascular cell adhesion molecule-1 (VCAM-1) were detected by Western blot. The expression levels of interleukin (IL-6, IL-10, IL-1ß) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay (ELISA). Results: Compared with blank control group, the contents of HDL and IL-10 and the expression level of MMP-1 protein were decreased in model group significantly (P＜0.05), while the levels of TG, ALT and AST, the positive rate of P65, α-SMA, TIMP-1, TLR4, TAK1, NF-κB p65, VCAM-1, IL-6, TNF-α and IL-1ß were increased significantly (P＜0.05). Compared with model group, the levels of HDL, IL-10 and MMP-1 protein were significantly increased after treatment with CBT and CC (P＜0.05), while the levels of TG, ALT, and AST, the positive rate of P65, α-SMA, TIMP-1, TLR4, TAK1, NF-κB p65, VCAM-1, IL-6, TNF-α and IL-1ß were decreased significantly (P＜0.05). The improvement in model+high- concentration CC group was the most significant, and which in all concentration groups was lower than that in model+CBT group (P＜0.05). Conclusion: CC can reduce inflammation response and improve liver function by regulating TLR4, TAK1 and NF-κB/p65 signaling pathway, and thus alleviating liver fibrosis, showing concentration-dependence within certain range.

Articular damages in multi-generational female offspring due to prenatal caffeine exposure correlates with H3K9 deacetylation of TGFß signaling pathway.

Adverse environment during pregnancy could lead to maternal glucocorticoid overexposure in utero, and then induce the intrauterine growth retardation (IUGR) and the programmed change in cartilage development. The transforming growth factor ß (TGFß) signaling pathway plays a crucial role in the process of chondrogenesis, cartilage growth, development, maturation, and phenotype maintenance. Our previous results had shown that prenatal caffeine exposure (PCE) could result in the damaged articular cartilage in offspring rats. However, whether this change could transmit to multiple generations was still unknown. In this study, pregnant Wistar rats received either saline or caffeine (120 mg/kg, i.g.) once daily from gestational day 9-20 (GD9-20). The female offspring mated with normal male rats to generate the following generations. We obtained the articular cartilages in subsequent F1 to F3 female offspring. The H3K9 acetylation and expression of the TGFß signaling pathway were detected; the content of the cartilage matrix was detected. The results showed that PCE reduced the H3K9 acetylation and the expression of the TGFß signaling pathway, then reduced the extracellular matrix in F1, F2, and F3 generations. in vitro, corticosterone could induce the H3K9 deacetylation of the TGFß signaling pathway, thus inhibiting the expression of the TGFß signaling pathway and extracellular matrix. The overall results revealed that PCE induced a multi-generational damaged articular cartilage in female offspring rats, which was partially related to the maternal high glucocorticoid-induced H3K9 hypoacetylation of TGFß signaling pathway.

Prenatal ethanol exposure induced disorder of hypothalamic-pituitary-adrenal axis-associated neuroendocrine metabolic programming alteration and dysfunction of glucose and lipid metabolism in 40-week-old female offspring rats.

This study was designed to demonstrate disorder of hypothalamic-pituitary-adrenal (HPA) axis-associated neuroendocrine metabolic programming alteration and dysfunction of glucose and lipid metabolism induced by prenatal ethanol exposure (PEE) in postnatal week 40 (PW40) female offspring rats. Pregnant Wistar rats were administrated 4  g/kg·d ethanol intragastrically from gestational day 11 until term delivery. After weaning, the female offspring were fed with high-fat diet until PW24, and suffered to unpredictable chronic stress (UCS) during PW38-40. Animal serum was collected to examine the changes in hypothalamic-pituitary-adrenal (HPA) axis activity, glucose and lipid metabolic phenotypes before and after UCS. We found that pups in the PEE group manifested a low birthweight at PW1 and an early catch-up growth pattern. Furthermore, a low basal activity of HPA axis continued to PW38 in the PEE group. On the basal condition, serum low-density lipoprotein-cholesterol (LDL-C) level was significantly increased and high-density lipoprotein-cholesterol (HDL-C) level was significantly decreased in the PEE group, while serum triglyceride, total cholesterol (TCH), glucose and insulin levels were not significantly changed. Under unpredictable chronic stress, serum insulin in the PEE group was significantly decreased, while the levels of serum triglyceride, TCH, LDL-C, and the ratio of LDL-C/HDL-C were significantly higher than those in the control. These results suggest that PEE increases the dysfunction of glucose and lipid metabolism in PW40 female offspring, which is related to the disorder of HPA axis-associated neuroendocrine metabolic programming alteration.

Reduced testicular steroidogenesis in rat offspring by prenatal nicotine exposure: Epigenetic programming and heritability via nAChR/HDAC4.

Prenatal nicotine exposure (PNE) may lead to offspring's testicular dysplasia. Here, we confirmed the intergenerational effect of PNE on testosterone synthetic function and explored its epigenetic programming mechanism. Pregnant Wistar rats were injected subcutaneously with nicotine (2 mg/kg.d) from gestational day 9-20. Some dams were anesthetized to obtain fetal rats, the rest were allowed to spontaneous labor to generate F1 and F2 generation. In utero, PNE impaired testicular development and testosterone production. Meanwhile, the expression of steroidogenic acute regulatory protein (StAR) and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) were decreased both in F1 and F2 generations. Furthermore, PNE enhanced the expression of fetal testicular nicotinic acetylcholine receptors (nAChRs) and histone deacetylase 4 (HDAC4), while obviously weakened histone 3 lysine 9 acetylation (H3K9ac) level of StAR/3ß-HSD promoter from GD20 to postnatal week 12 and even in F2 generation. In vitro, nicotine increased nAChRs and HDAC4 expression, and decreased the StAR/3ß-HSD H3K9ac level and expression, as well as the testosterone production in Leydig cells. Antagonism of nAChRs and inhibition of HDAC4 reversed the aforementioned changes. In conclusion, PNE programmed testicular low steroidogenesis and its heritability in male offspring rats. The underlying mechanism was associated to the low-level programming of StAR/3ß-HSD H3K9ac via nAChR/HDAC4.

Prenatal ethanol exposure induces susceptibility to premature ovarian insufficiency.

Prenatal ethanol exposure (PEE) adversely affects the offspring reproductive system. We aimed to confirm the susceptibility to premature ovarian insufficiency (POI) in female PEE offspring and elucidate its intrauterine programming mechanism. The pregnant Wistar female rats were intragastrically administered with 4 g/kg×d of ethanol from gestational day (GD) 9 to 20. Offspring reproductive parameters were detected on GD20, postnatal week (PW) 6, and PW12. The PEE foetuses showed a decreased number of oocytes, increased ovarian cell apoptosis, and upregulated expression levels of ovarian insulin-like growth factor 1 (IGF1) signaling pathway and steroidogenic enzymes. The proportion of atretic follicles in adult rats was increased, while the number of anti-Müllerian hormone-positive antral follicles was decreased. The serum oestradiol (E2) levels were decreased, but the follicle stimulation hormone levels were elevated. The ovarian Igf1 signaling pathway was transformed from activation during puberty to relative inhibition in adulthood, and the expression levels of ovarian steroidogenic enzymes were inhibited in adulthood. Furthermore, we treated the human granulosa cell line KGN with different ethanol concentrations (15, 30, 60, 120 mM) and found that the expression of IGF1 signaling pathway components, 3ß-HSD, and P450arom, as well as the production of E2, was increased. After IGF1 siRNA transfection, P450arom expression and E2 production were downregulated. These results suggest that PEE induces POI susceptibility in adult females, which may be caused by over-activation of the foetal ovarian Igf1 signaling pathway and steroidogenesis under PEE, resulting in accelerated early development of folliculogenesis and depletion of primordial follicles.

The GC-IGF1 axis-mediated testicular dysplasia caused by prenatal caffeine exposure.

Prenatal caffeine exposure (PCE) can induce testicular developmental toxicity. Here, we aimed to explore the underlying mechanism of this process in reference to its intrauterine origin. Pregnant rats were intragastrically administrated caffeine (30 and 120 mg/kg/day) from gestational days 9 to 20. The results showed that the male fetuses exposed to high dose of caffeine (120 mg/kg/day) had a decreased bodyweight and inhibited testosterone synthetic function. Meanwhile, their serum corticosterone concentration was elevated and their testicular insulin-like growth factor 1 (Igf1) expression was decreased. Moreover, the histone 3 lysine 14 acetylation (H3K14ac) level in the Igf1 promoter region was reduced. Low-dose (30 mg/kg/day) caffeine exposure, however, increased steroidogenic enzymes expression in male fetuses. After birth, the serum corticosterone concentration gradually decreased in the PCE (120 mg/kg/day) offspring rats, whereas the expression and H3K14ac level of Igf1 gradually increased, with obvious catch-up growth and testicular development compensation. Intriguingly, when we subjected the offspring to 2 weeks of chronic stress to elevate the serum corticosterone concentration, the expression of Igf1 and testosterone synthesis were inhibited again in the PCE (120 mg/kg/day) group, accompanied by a decrease in the H3K14ac level in the Igf1 promoter region. In vitro, corticosterone (rather than caffeine) was proved to inhibit testosterone production in Leydig cells by altering the H3K14ac level and the expression of Igf1. These observations suggested that PCE-induced testicular developmental toxicity is related to the negative regulation of corticosterone on H3K14ac levels and the expression of Igf1.

Corticosterone rather than ethanol epigenetic programmed testicular dysplasia caused by prenatal ethanol exposure in male offspring rats.

Prenatal ethanol exposure (PEE) could affect offspring's testicular development. This study aimed to illuminate its intrauterine origin and the programming mechanism caused by PEE. Pregnant Wistar rats were given ethanol (4 g/kg.d) by gavage administration during gestational days (GD) 9-20. Serum samples and testes of male offspring rats were collected on GD20, postnatal week (PW) 6, and PW12. We found that PEE induced testicular morphological abnormality, low serum testosterone levels, expressive suppression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD), and low acetylation levels of histone 3 lysine 14 (H3K14ac) of 3ß-HSD before and after birth. In utero, when fetal rats were overexposed to corticosterone by PEE, the expression levels of testicular glucocorticoid receptor (GR) and histone deacetylase 2 (HDAC2) were increased, while that of steroidogenic factor 1 (SF1) was decreased. In vitro, corticosterone (rather than ethanol) at 500 to 2,000 nM concentration decreased testosterone production and 3ß-HSD expression in a concentration-dependent manner. Moreover, corticosterone downregulated SF1 and upregulated HDAC2 via activating GR, accompanied by a low H3K14ac level of 3ß-HSD; SF1 overexpression could reverse the increased HDAC2 expression, and knockdown of HDAC2 could partially reverse the inhibitory effects of corticosterone on H3K14ac level and 3ß-HSD expression but not on SF1 expression. Taken together, PEE caused testicular dysplasia in male offspring rats, which was associated with corticosterone-induced low-functional programming of 3ß-HSD through the GR/SF1/HDAC2/H3K14ac pathway. This study provides new academic perspectives to illuminate the theory of 'Developmental Origins of Health and Disease.'

Excitotoxicity and compensatory upregulation of GAD67 in fetal rat hippocampus caused by prenatal nicotine exposure are associated with inhibition of the BDNF pathway.

Prenatal nicotine exposure (PNE) can cause hypersensitivity of hypothalamic-pituitary-adrenal (HPA) axis in offspring with intrauterine growth retardation. The purpose of this study was to explore the original mechanism of intrauterine development that mediates hypersensitivity of the HPA axis in offspring due to PNE. Pregnant Wistar rats were injected subcutaneously with 2 mg/kg·d of nicotine on the 9th to the 20th gestational day (GD9-GD20) and the fetuses were extracted at GD20. Compared with the control group, fetal rats by PNE showed increased hippocampal apoptosis, reduced synaptic plasticity and downregulation of the brain-derived neurotrophic factor (BDNF) pathway, whereas glutamic acid decarboxylase 67 (GAD67) expression was upregulated. Rat fetal hippocampal H19-7/IGF1R cell lines were treated with different concentrations of nicotine (1, 10 and 100 µM) for 3 days, the extracellular fluid glutamate (Glu) level increased and similar effects were observed as in vivo. Intervention treatments caused the opposite results. These results indicated that PNE downregulates the BDNF pathway and mediates the hippocampal excitotoxicity; then, the compensatory upregulation of GAD67 causes the imbalance of signal output in the fetal hippocampus. The negative feedback regulation of the paraventricular hypothalamic nucleus by the hippocampus is unbalanced, eventually causing hypersensitivity of the HPA axis of the offspring.

Decreased H3K9ac level of AT2R mediates the developmental origin of glomerulosclerosis induced by prenatal dexamethasone exposure in male offspring rats.

This study aimed to demonstrate that prenatal dexamethasone exposure (PDE) can induce kidney dysplasia in utero and adult glomerulosclerosis in male offspring, and to explore the underlying intrauterine programming mechanisms. Pregnant rats were subcutaneously administered dexamethasone 0.2 mg/kg.d from gestational day (GD) 9 to GD20. The male fetus on GD20 and the adult offspring at age of postnatal week 28 were analyzed. The adult offspring kidneys in the PDE group displayed glomerulosclerosis, elevated levels of serum creatinine and urine protein, ultrastructural damage of podocytes, the reduced expression levels of podocyte marker genes, nephrin and podocin. The histone 3 lysine 9 acetylation (H3K9ac) level in the promoter of renal angiotensin II receptor type 2 (AT2R) and its expression were reduced, whereas the angiotensin II receptor type 1a (AT1aR)/AT2R expression ratio was increased. The fetal kidneys in the PDE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio, reduced the expression level of glial-cell-line derived neurotrophic factor/c-Ret tyrosine kinase receptor (GDNF/c-Ret) signal pathway and podocyte marker genes. Moreover, the H3K9ac and H3K27ac levels of AT2R as well as the gene and protein expression levels of AT2R in fetal kidneys were inhibited by PDE. In vitro, primary metanephric mesenchyme stem cells (MMSCs) were treated with dexamethasone. Overexpression of AT2R reversed the inhibited expression of GDNF/c-Ret and podocin/nephrin induced by dexamethasone, and glucocorticoids receptor antagonist abolished the decreased H3K9ac level and gene expression of AT2R. In conclusion, PDE induced the offspring's kidney dysplasia as well as adult glomerulosclerosis, which was mediated by a sustained decrease in renal AT2R expression via decreasing the H3 K9ac level.

Decreased H3K9ac level of StAR mediated testicular dysplasia induced by prenatal dexamethasone exposure in male offspring rats.

Prenatal dexamethasone exposure (PDE) could induce testicular developmental toxicity in adults. The present study aims to confirm its intrauterine origination, and to explore its potential intrauterine programming mechanism. The pregnant rats were respectively injected subcutaneously with 0.2 and 0.8 mg/kg d dexamethasone during gestational days (GD) 9 to 20. The testes and serum of offspring rats were collected on GD20 and postnatal week (PW) 12. In vivo, PDE significantly induced the abnormal testicular morphology in offspring from GD20 to PW12. Moreover, the serum and intratesticular testosterone levels and the expression of testicular steroidogenic acute regulatory protein (StAR) were reduced by PDE. The expression levels of glucocorticoid receptor (GR) and histone deacetylase 7 (HDAC7) were increased in fetal testes. Furthermore, the histone 3 lysine 9 acetylation (H3K9ac) level in the StAR promoter was decreased by PDE from GD20 to PW12. In vitro, mouse Leydig tumour cell line (MLTC-1) cells were treated with dexamethasone (20, 100 and 500 nM), and the testosterone production and StAR expression were reduced. Moreover, dexamethasone increased the expression of HDAC7 by activating GR, which decreased the H3K9ac level in the StAR promoter. Taken together, PDE caused testicular dysplasia before and after birth in male offspring rats, and its mechanism was related to the low-expressional programming of StAR mediated by decreasing H3K9ac level.

cAMP/PKA/EGR1 signaling mediates the molecular mechanism of ethanol-induced inhibition of placental 11ß-HSD2 expression.

It is known that inhibiting 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) expression in the placenta can cause fetal over-exposure to maternal glucocorticoids and induce intrauterine growth restriction (IUGR); these effects ultimately increase the risk of adult chronic diseases. This study aimed to investigate the molecular mechanism of the prenatal ethanol exposure (PEE)-induced inhibition of placental 11ß-HSD2 expression. Pregnant Wistar rats were intragastrically administered ethanol (4 g/kg/d) from gestational days 9 to 20. The levels of maternal and fetal serum corticosterone and placental 11ß-HSD2-related gene expression were analyzed. Furthermore, we investigated the mechanism of reduced placental 11ß-HSD2 expression induced by ethanol treatment (15-60 mM) in HTR-8/SVneo cells. In vivo, PEE decreased fetal body weights and increased maternal and fetal serum corticosterone and early growth response factor 1 (EGR1) expression levels. Moreover, histone modification changes (decreased acetylation and increased di-methylation of H3K9) to the HSD11B2 promoter and lower 11ß-HSD2 expression levels were observed. In vitro, ethanol decreased cAMP/PKA signaling and 11ß-HSD2 expression and increased EGR1 expression in a concentration-dependent manner. A cAMP agonist and EGR1 siRNA reversed the ethanol-induced inhibition of 11ß-HSD2 expression. Together, PEE reduced placental 11ß-HSD2 expression, and the underlying mechanism is associated with ethanol-induced histone modification changes to the HSD11B2 promoter through the cAMP/PKA/EGR1 pathway.

Prenatal nicotine exposure intergenerationally programs imperfect articular cartilage via histone deacetylation through maternal lineage.

Accumulating evidence has shown that the impact of prenatal environmental factors on the organs of the offspring could last until the adulthood. Here, we aimed to investigate these effects and the potential mechanism of prenatal nicotine exposure (PNE) on the female adult cartilage of the first generation (PNE-F1) and the second generation (PNE-F2). Pregnant Wistar rats were injected with 2.0 mg/kg.d nicotine from gestational day (GD) 9 to 20. Then their F1 generation at GD20 and postnatal week (PW) 12, and F2 generation at PW12 were harvested. The expression of extracellular matrix (ECM) and transforming growth factor ß (TGFß) signaling genes were analyzed by real-time quantitative PCR, and the histone acetylation was examined by chromatin immunoprecipitation assay. The results showed that PNE reduced the ECM and TGFß signaling gene expressions in both PNE-F1 and PNE-F2 female adult articular cartilage. In the F1 generation, PNE inhibited the acetylation at H3K9 of TGFß, TGFß receptor 1 (TGFßR1), SRY-type high mobility group box 9 (SOX9), a1 chain of type II collagen (COL2A1) and aggrecan (ACAN) gene promoters at both GD20 and PW12. In PNE-F2 at PW12, the obvious deacetylation at H3K9 of the TGFßR1 and COL2A1 promoters still existed. Moreover, in rat fetal chondrocytes, corticosterone rather than nicotine directly induced the hypoacetylation of H3K9 of TGFßR1 and COL2A1 genes, which might be the main cause of imperfect cartilage for PNE-F2. This study may be helpful to elucidate the developmental variability of articular cartilage quality and useful for the early prevention of articular damage.

Prenatal Dexamethasone Exposure Induced Ovarian Developmental Toxicity and Transgenerational Effect in Rat Offspring.

Prenatal dexamethasone exposure (PDE) induces multiorgan developmental toxicities in offspring. Here we verified the transgenerational inheritance effect of ovarian developmental toxicity by PDE and explored its intrauterine programming mechanism. Pregnant rats subcutaneously received 0.2 mg/kg/d dexamethasone from gestational day (GD) 9 to GD20. A subgroup was euthanized for fetuses on GD20, and the other group went on to spontaneous labor to produce F1 offspring. The adult F1 females were mated with normal males to produce the F2 and F3 generations. The PDE fetal rats exhibited ovarian mitochondrial structural abnormalities, decreased serum estradiol (E2) levels, and lower expression levels of ovarian steroidogenic factor 1 (SF1), steroidal synthetases, and insulinlike growth factor 1 (IGF1). On postnatal week (PW) 6 and PW12, the PDE F1 offspring showed altered reproductive behavior and ovarian morphology. The serum E2 level and ovarian expression of SF1, steroidal synthetases, and IGF1 were also decreased. The adult F3 offspring showed alterations in reproductive phenotype and ovarian IGF1, SF1, and steroidal synthetase expression similar to those of F1. PDE induces ovarian developmental toxicity and transgenerational inheritance effects. The mechanism by which this toxicity occurs may be related to PDE-induced low-functional programming of fetal ovarian IGF1/SF1 and steroidal synthetases.

Effects of prenatal caffeine exposure on glucose homeostasis of adult offspring rats.

Epidemiological evidences show that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR). The IUGR offspring also present glucose intolerance and type 2 diabetes mellitus after maturity. We have previously demonstrated that PCE induced IUGR and increased susceptibility to adult metabolic syndrome in rats. This study aimed to further investigate the effects of PCE on glucose homeostasis in adult offspring rats. Pregnant rats were administered caffeine (120 mg/kg/day, intragastrically) from gestational days 11 to 20. PCE offspring presented partial catch-up growth pattern after birth, characterizing by the increased body weight gain rates. Meanwhile, PCE had no significant influences on the basal blood glucose and insulin phenotypes of adult offspring but increased the glucose tolerance, glucose-stimulated insulin section and ß cell sensitivity to glucose in female progeny. The insulin sensitivity of both male and female PCE offspring were enhanced accompanied with reduced ß cell fraction and mass. Western blotting results revealed that significant augmentation in protein expression of hepatic insulin signaling elements of PCE females, including insulin receptor (INSR), insulin receptor substrate 1 (IRS-1) and the phosphorylation of serine-threonine protein kinase (Akt), was also potentiated. In conclusion, we demonstrated that PCE reduced the pancreatic ß mass but increased the glucose tolerance in adult offspring rats, especially for females. The adaptive compensatory enhancement of ß cell responsiveness to glucose and elevated insulin sensitivity mainly mediated by upregulated hepatic insulin signaling might coordinately contribute to the increased glucose tolerance.

Prenatal caffeine exposure induced high susceptibility to metabolic syndrome in adult female offspring rats and its underlying mechanisms.

Our previous studies have demonstrated that prenatal caffeine exposure (PCE) induced an intrauterine programming of hypothalamic-pituitary-adrenal axis (HPAA)-associated neuroendocrine metabolism in 3-month-old offspring rats. In this study, we aimed to confirm this programming disorder and high susceptibility to metabolic syndrome (MS) in 10-month-old female PCE offspring with postnatal catch-up growth. We found that PCE female offspring rats showed decreased bodyweight but a higher rate of weight gain after birth. Moreover, in the offspring, basal hyperinsulinemia and insulin resistance were observed before unpredictable chronic stress (UCS), but serum total cholesterol (TCH) levels and triglyceride/high-density lipoprotein-cholesterol (TG/HDL-C), TCH/HDL-C and low-density lipoprotein-cholesterol/HDL-C (LDL-C/HDL-C) ratio changes were increased after UCS, accompanied by morphological damage of the related tissues. These results suggested that PCE adult female offspring rats were highly susceptible to MS, which is related to HPAA-associated neuroendocrine-metabolic programming disorder.