Hisashi Masuyama

Effects of a High-Fat Diet Exposure in Utero on the Metabolic Syndrome-Like Phenomenon in Mouse Offspring through Epigenetic Changes in Adipocytokine Gene Expression

The links between obesity in parents and their offspring and the role of genes and a shared environment are not completely understood. Adipocytokines such as leptin and adiponectin play important roles in glucose and lipid metabolism. Therefore, we examined whether the offspring from dams exposed to a high-fat diet during pregnancy (OH mice) exhibited hypertension, insulin resistance, and hyperlipidemia along with epigenetic changes in the expression of adipocytokine genes. OH mice were significantly heavier than the offspring of dams exposed to a control diet during pregnancy (OC mice) from 14 wk of age after an increased caloric intake from 8 wk. OH mice exhibited higher blood pressure and worse glucose tolerance than the OC mice at 24 wk. Total triglyceride and leptin levels were significantly higher and the adiponectin level was significantly lower in OH compared with OC mice at 12 wk of age. This was associated with changes in leptin and adiponectin expression in white adipose tissue. There were lower acetylation and higher methylation levels of histone H3 at lysine 9 of the promoter of adiponectin in adipose tissues of OH mice at 2 wk of age as well as at 12 and 24 wk of age compared with OC mice. In contrast, methylation of histone 4 at lysine 20 in the leptin promoter was significantly higher in OH compared with OC mice. Thus, exposure to a high-fat diet in utero might cause a metabolic syndrome-like phenomenon through epigenetic modifications of adipocytokine, adiponectin, and leptin gene expression.

The expression of pregnane X receptor and its target gene, cytochrome P450 3A1, in perinatal mouse.

Recently, pregnane X receptor (PXR) has been described to mediate the genomic effects of several steroid hormones, such as progesterone (P), glucocorticoid (Dex), pregnenolone (Preg), and xenobiotics through the cytochrome P-450 3A gene family (CYP3A), which are monooxygenases, responsible for the oxidative metabolism of some endogenous substrates and xenobiotics. In the present study, we used a transient transfection reporter gene expression assay of COS-7 cells to demonstrate that P, Dex and Preg significantly stimulate PXR-mediated transcription at relatively high concentration comparable with that of progesterone near term pregnancy. In yeast two-hybrid protein interaction assay, PXR interacted with nuclear receptor coactivator proteins, SRC1, RIP140, and SUG1 in a ligand-dependent manner. The expression of PXR mRNA was observed in the liver, intestine, uterus, ovary and placenta. The expressions of PXR mRNA in the liver and ovary increased towards term about fifty-fold compared with that of non-pregnancy and decreased postpartum. Its expression in the placenta was not drastically changed towards term. CYP3A, a target gene of PXR, was also expressed in the liver, ovary, and placenta. The expressions of CYP3A mRNA as well as PXR in the liver and ovary increased about 20-fold during prenatal period. These data suggest that PXR may play certain roles in perinatal period, possibly in the protection of the feto-maternal system from the toxic effect of endogenous steroids and foreign substrates.

Different profiles of circulating angiogenic factors and adipocytokines between early- and late-onset pre-eclampsia.

Please cite this paper as: Masuyama H, Segawa T, Sumida Y, Masumoto A, Inoue S, Akahori Y, Hiramatsu Y. Different profiles of circulating angiogenic factors and adipocytokines between early‐ and late‐onset pre‐eclampsia. BJOG 2010;117:314–320.

Down-regulation of pregnane X receptor contributes to cell growth inhibition and apoptosis by anticancer agents in endometrial cancer cells.

Recent studies have revealed that pregnane X receptor (PXR) can function as a master regulator to control the expression of drug-metabolizing enzymes, cytochrome P450 3A (CYP3A) family, and members of the drug transporter family, including multiple drug resistance 1 (MDR1). We demonstrated previously that steroid/xenobiotic metabolism by tumor tissue through the PXR-CYP3A pathway might play an important role in endometrial cancer and that PXR ligands enhance PXR-mediated transcription in a ligand- and promoter-dependent fashion, leading to differential regulation of individual PXR targets, especially CYP3A4 and MDR1. In this study, we investigated the potential contribution of PXR down-regulation by RNA interference toward the augmentation of drug sensitivity and the overcoming of drug resistance. We observed the protein levels of both CYP3A4 and MDR1 in PXR small interfering RNA (siRNA)-transfected cells were not increased in the presence of PXR ligands, paclitaxel, cisplatin, estradiol, or medroxyprogesterone acetate (MPA) compared with control siRNA-transfected cells. There was no PXR-mediated transactivation or augmentation of transcription by coactivators in the presence of these ligands. We then found that PXR down-regulation caused a significant increase in cell growth inhibition and enhancement of apoptosis in the presence of the anticancer agents, paclitaxel, cisplatin, and MPA. Finally, we demonstrated that PXR overexpression caused a significant decrease in cell growth inhibition and inhibited apoptosis in the presence of paclitaxel or cisplatin. These data suggest that PXR down-regulation could be a novel therapeutic approach for the augmentation of sensitivity to anticancer agents, or to overcome resistance to them, in the treatment of endometrial cancer.

The Effects of High-Fat Diet Exposure In Utero on the Obesogenic and Diabetogenic Traits Through Epigenetic Changes in Adiponectin and Leptin Gene Expression for Multiple Generations in Female Mice

Recent studies demonstrate that epigenetic changes under malnutrition in utero might play important roles in transgenerational links with metabolic diseases. We have previously shown that exposure to a high-fat diet (HFD) in utero may cause a metabolic syndrome-like phenomenon through epigenetic modifications of Adiponectin and Leptin genes. Because an association of obesity between mother and offspring endured in multiple generations, we examined whether HFD exposure in utero might affect the metabolic status of female offspring through multigenerational epigenetic changes of Adiponectin and Leptin genes and whether a normal diet in utero for multiple generations might abolish such epigenetic changes after exposure to a HFD in utero using ICR mice. We observed that the effect of maternal HFD on offspring over multiple generations in metabolic syndrome-like phenomenon such as weight and fat mass gain, glucose intolerance, hypertriglyceridemia, abnormal adiponectin and leptin levels, and hypertension, were accumulated with expression and epigenetic changes in Adiponectin and Leptin genes. A normal diet in utero in the subsequent generations after HFD exposure in utero diminished, and a normal diet in utero for 3 generations completely abolished, the effect of HFD in utero on weight and fat mass gain, insulin resistance, serum triglyceride, adiponectin, and leptin levels, with epigenetic changes of Adiponectin and Leptin genes. Exposure to a HFD in utero might affect glucose and lipid metabolism of female offspring through epigenetic modifications to Adiponectin and Leptin genes for multiple generations. Obesogenic and diabetogenic traits were abolished after a maternal normal diet for 3 generations.

Superimposed Preeclampsia in Women with Chronic Kidney Disease

Aim: To evaluate whether pregnant women with chronic kidney disease (CKD) adapt poorly to increases in renal blood flow. This can exacerbate renal function and impair perinatal outcome, as there is a major interplay between CKD and preeclampsia (PE). Methods: We analyzed the outcomes of 90 pregnant women with preexisting CKD. The estimated glomerular filtration rate (eGFR) was measured along with the levels of angiogenic factors, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor, which might act in the pathophysiology of PE. Results: In pregnancies with CKD, PE and preterm delivery were increased and the increased blood pressure worsened the perinatal outcomes much more than the increased proteinuria. All pregnancies with severe renal insufficiency were delivered preterm because of impaired renal function. The eGFR was correlated significantly with 24-hour creatinine clearance (r = 0.830). Significant differences in sFlt-1 and placental growth factor levels were found between severe PE without any complications and severe superimposed PE (p < 0.05), and between women with and without declining renal function in superimposed PE (p < 0.01). Conclusion: Pregnancies with CKD have a high risk of obstetrical complications. The eGFR might serve for evaluating renal function during pregnancy. Angiogenic factors might be potential markers for a differential diagnosis between PE and worsening renal function.

Inhibition of placental ornithine decarboxylase by DL-α-difluoro-methyl ornithine causes fetal growth restriction in rat

The roles of polyamines in intrauterine growth restriction (IUGR) is studied. The DL-alpha-difluoromethyl ornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC) which is a rate limiting enzyme of polyamine synthesis was administrated to pregnant rats so that we obtained rat fetuses with IUGR. The changes of maternal nutrition, damage of the placenta, and the direct effect of DFMO on the fetus were examined in this IUGR model. Administration of DFMO did not induced changes of maternal nutrition except for triglyceride and the fetal metabolic state. But the placental weight, ODC activity, and DNA in the placenta were decreased significantly. The ODC activity in the total placenta decreased to less than 10% of that of the control. Depression of ODC activity in the placenta may be the major cause of IUGR induced by DFMO administration, and polyamines play important roles to carry pregnancy.

The effects of paternal high-fat diet exposure on offspring metabolism with epigenetic changes in the mouse adiponectin and leptin gene promoters

Recent studies have demonstrated that epigenetic changes resulting from malnutrition might play important roles in transgenerational links with metabolic diseases. Previously, we observed that exposure to a high-fat diet (HFD) in utero caused a metabolic syndrome-like phenomenon through epigenetic modifications of the adiponectin and leptin genes that persisted for multiple generations. Recent etiological studies indicated that paternal BMI had effects on offspring BMI that were independent of but additive to maternal BMI effects. Thus, we examined whether paternal HFD-induced obesity affected the metabolic status of offspring through epigenetic changes in the adiponectin and leptin genes. Additionally, we investigated whether a normal diet during subsequent generations abolished the epigenetic changes associated with paternal HFD exposure before conception. We observed the effects of paternal HFD exposure before conception over multiple generations on offspring metabolic traits, including weight and fat gain, glucose intolerance, hypertriglyceridemia, abnormal adipocytokine levels, hypertension, and adiponectin and leptin gene expression and epigenetic changes. Normal diet consumption by male offspring during the subsequent generation following paternal HFD exposure diminished whereas consumption for two generations completely abolished the effect of paternal HFD exposure on metabolic traits and adipocytokine promoter epigenetic changes in the offspring. The effects of paternal HFD exposure on offspring were relatively weaker than those following HFD exposure in utero. However, paternal HFD exposure had an additive metabolic effect for two generations, suggesting that both paternal and maternal nutrition might affect offspring metabolism through epigenetic modifications of adipocytokine genes for multiple generations.

Additive effects of maternal high fat diet during lactation on mouse offspring.

Recent reports indicated that nutrition in early infancy might influence later child health outcomes such as obesity and metabolic syndrome. Therefore, we examined the effects of maternal high fat diet (HFD) during lactation on the onset of a metabolic syndrome in their offspring. All offspring were cross-fostered by dams on the same or opposite diet to yield 4 groups: offspring from HFD-fed dams suckled by HFD-fed dams (OHH) and by control diet (CD)-fed dams (OHC) and CD-fed dams suckled by HFD-fed dams (OCH) and by CD-fed dams (OCC) mice. We examined several metabolic syndrome-related factors including body weight, blood pressure, glucose tolerance and adipocytokines. Mean body weights of OHH and OCH mice were significantly higher than those of OHC and OCC mice, respectively, with elevated systolic blood pressure. Moreover, OHH and OCH mice revealed significantly worse glucose tolerance compared with the OHC and OCC mice, respectively. Triglyceride and leptin levels were significantly increased and adiponectin levels were significantly reduced by the maternal HFD during lactation, with similar changes in leptin and adiponectin mRNA expression but without histone modifications in adipose tissues. In addition, maternal obesity induced by HFD during lactation increased and prolonged the leptin surge in the offspring and the gender differences of leptin surge were observed. Our data suggested that maternal HFD during lactation might have an additive effect on the onset of the metabolic syndrome in the offspring, irrespective of the nutritional status in utero through the modified leptin surge.

Treatment with a constitutive androstane receptor ligand ameliorates the signs of preeclampsia in high-fat diet-induced obese pregnant mice.

Constitutive androstane receptor (CAR) has been reported to decrease insulin resistance, while obesity and insulin resistance may also be involved in the pathogenesis of preeclampsia. We examined whether a CAR ligand, 1,4-bis(2-(3,5-dichloropyridyloxy)) benzene (TCPOBOP), can ameliorate the signs of preeclampsia in high-fat diet (HFD)-induced obese pregnant mice to examine a possibility of CAR as a therapeutic target. We employed six groups including non-pregnant, HFD-fed or control diet-fed pregnant mice with or without TCPOBOP treatment (n=6). In HFD pregnant mice, insulin resistance increased with increasing expression of gluconeogenic and lipogenic genes and abnormal adipocytokine levels. TCPOBOP treatment, which was once-weekly intraperitoneal injections (0.5 mg/kg) and started at day 0.5 of pregnancy, improved glucose tolerance with significant changes of gluconeogenic, lipogenic and adipocytokine genes. HFD pregnant mice had hypertension and proteinuria, while TCPOBOP treatment ameliorated these signs. Our data suggested CAR might be a potential therapeutic target for obese preeclampsia patients with insulin resistance.