Nao Murabayashi

Maternal high-fat diets cause insulin resistance through inflammatory changes in fetal adipose tissue

OBJECTIVES Epidemiological and animal studies have shown that maternal obesity predisposes the offspring to obesity and the metabolic syndrome, possibly via late-onset metabolic programming of the fetus. Little is known, however, about the metabolic effect of maternal obesity on the fetus. This study investigated the effect of a maternal high-fat diet (HFD) on fetal growth and glucose metabolism using a diet-induced obesity mouse model. STUDY DESIGN Female mice (6 weeks old; C57BL/6N) were fed either a normal chow diet (NCD, 10 kcal% fat) or an HFD (60 kcal% fat) for 4 weeks before mating and throughout pregnancy. At 17 days of gestation, gene expression of inflammatory markers and adipokines in fetal subcutaneous adipose tissue was analyzed by quantitative real-time polymerase chain reaction. RESULTS HFD mice were overweight, glucose intolerant and insulin resistant compared with NCD mice of the same gestational age. Although fetal body weight was not significantly different, fetal plasma glucose and insulin levels were higher in the HFD group than the NCD group. Furthermore, examination of fetal subcutaneous adipose tissue in the HFD group revealed hypertrophy with an increase in the levels of cluster of differentiation-68, chemokine receptor-2 and tumor necrosis factor-α mRNA, but a decrease in the level of glucose transporter-4 mRNA. CONCLUSION Maternal HFD causes inflammatory changes in the adipose tissue of offspring.

The inflammatory changes of adipose tissue in late pregnant mice

The infiltration of classically activated macrophages (M1) and alternatively activated macrophages (M2) in subcutaneous adipose tissue (SAT) and parametrial adipose tissue (PAT) was analyzed to investigate whether local inflammatory change in adipose tissue occurs in late pregnancy. C57BL/6N female mice at 6 weeks of age were fed a normal chow diet for 4 weeks prior to mating at 10 weeks of age and were sampled on day 17 of pregnancy. The serum levels of adipokines and biochemical markers were measured using ELISA and enzymatic methods. The identification of M1 and M2 was analyzed by double immunofluorescence with anti-F4/80 and anti-CD11c antibodies. The gene expression of adipokines in adipose tissues was analyzed by quantitative RT-PCR. The pregnant group showed adipocyte hypertrophy, higher macrophage infiltration, and higher M1/M2 in both SAT and PAT compared with the non-pregnant (NP) group. Serum levels of free fatty acids, tumor necrosis factor α (TNFα), interleukin 6 (IL6), and IL10 were higher, and serum levels of adiponectin were lower in the pregnant group than those in the NP group. The gene expressions of CD68, Itgax, CCR2, TNFα, and PAI1 in SAT during pregnancy were significantly higher than those in the NP group, as were the gene expressions of CD68, Emrl, Itgax, MCP1, TNFα, IL6, PAI1, adiponectin, and IL10 in PAT. These results suggest that the low-grade inflammation of adipose tissue indicated by increased macrophage infiltration occurs in late normal pregnancy.

Transgenic mice overproducing human thioredoxin-1, an antioxidative and anti-apoptotic protein, prevents diabetic embryopathy

Aims/hypothesisExperimental studies have suggested that apoptosis is involved in diabetic embryopathy through oxidative stress. However, the precise mechanism of diabetic embryopathy is not yet clear. Thioredoxin (TRX) is a small, ubiquitous, multifunctional protein, which has recently been shown to protect cells from oxidative stress and apoptosis. Using transgenic mice that overproduce human TRX-1 (TRX-Tg mice), we examined whether oxidative stress is involved in fetal dysmorphogenesis in diabetic pregnancies.MethodsNon-diabetic and streptozotocin-induced diabetic (DM) female mice were mated with male TRX-Tg mice. Pregnant mice were killed either at day 10 or day 17 of gestation, and viable fetuses and their placentas were recovered, weighed and assessed for gross and histological morphology, biochemical markers and gene expression.ResultsIn both wild-type (WT) and transgenic (Tg) groups, fetal and placental weights in the diabetic group were significantly decreased compared with the non-diabetic group. The incidence of malformation was higher in the diabetic group, and was significantly decreased in the TRX-Tg group (DM-WT vs DM-Tg; 28.6% vs 10.4%). Oxidative stress markers such as thiobarbituric acid reactive substances and 8-hydroxy-2′-deoxyguanosine were increased in DM-WT group fetuses but were decreased in fetuses from the DM-Tg group. Furthermore, immunohistochemically assayed apoptosis and cleaved caspase-3 production in embryonic neuroepithelial cells was significantly increased in the DM-WT group, and was significantly decreased in the DM-Tg group.Conclusions/interpretationThese results indicate that oxidative stress is involved in diabetic embryopathy, and that the antioxidative protein TRX at least partially prevents diabetic embryopathy via suppression of apoptosis.

The Effects of Antenatal Corticosteroids on Short- and Long-Term Outcomes in Small-for-Gestational-Age Infants.

Aim: To evaluate the effect of antenatal corticosteroids (ANS) on short- and long-term outcomes in small-for-gestational age (SGA) infants. Methods: A retrospective database analysis was performed. A total of 1,931 single infants (birth weight <1,500 g) born at a gestational age between 22 weeks and 33 weeks 6 days who were determined to be SGA registered in the Neonatal Research Network Database in Japan between 2003 and 2007 were evaluated for short-term outcome and long-term outcome. Results: ANS was administered to a total of 719 infants (37%) in the short-term outcome evaluation group and 344 infants (36%) in the long-term outcome evaluation group. There were no significant differences between the ANS group and the no-ANS group for primary short-term outcome (adjusted odds ratio (OR) 0.73; 95% confidence interval (CI) 0.45-1.20; P-value 0.22) or primary long-term outcome (adjusted OR 0.69; 95% CI 0.40-1.17; P-value 0.17). Conclusions: Our results show that ANS does not affect short- or long-term outcome in SGA infants when the birth weight is less than 1500 g. This study strongly suggests that administration of ANS resulted in few benefits for preterm FGR fetuses.

Thoracoamniotic Shunting with Double-Basket Catheters for Fetal Chylothorax in the Second Trimester

The progress of a fetal severe pleural effusion at mid-trimester is extremely poor. We encountered a fetus that developed a severe left pleural effusion at 21 weeks of gestation. The pleural effusion was removed by thoracocentesis at 22 weeks. Cytology revealed abundant lymphocytes, suggesting chylothorax. However, a reaccumulation of pleural effusion with hydrops was subsequently noted, and a thoracoamniotic shunt with double-basket catheters was installed at 23 weeks. The pleural effusion decreased after 24 weeks and completely disappeared at 26 weeks. At 40 weeks of gestation, a female infant was born by vaginal delivery, with no evidence of pleural effusion. We would like to stress that thoracoamniotic shunt with double-basket catheters in the second trimester is effective for pleural effusion with hydrops.

Impact of chorioamnionitis on short- and long-term outcomes in very low birth weight preterm infants: the Neonatal Research Network Japan

Abstract Objective: To evaluate the short- and long-term outcomes among very low birth weight (VLBW) preterm infants after histologic chorioamnionitis (HCA). Methods: We performed a retrospective analysis of 5849 single infants (birth weight <1500 g) born at a gestational age between 22 + 0 and 33 + 6 weeks. Clinical data were obtained from the Neonatal Research Network Japan between 2003 and 2007. Multivariable logistic regression analyses were performed to assess the effect of HCA on short- and long-term outcome. Results: According to logistic regression analysis, HCA was associated with lower incidence of respiratory distress syndrome (odds ratio [OR] = 0.54; p < 0.001), increased chronic lung disease (OR = 1.68; p < 0.001) and sepsis (OR = 1.71; p < 0.001) and as a short-term outcomes. There was no significant association with intraventricular hemorrhage (OR = 1.11; p = 0.33), periventricular leukomalacia (OR = 1.07; p = .070) and death before discharge (OR = 0.97; p = 0.084). HCA was associated with increased home oxygen therapy (OR = 3.09; p < 0.001), but not with cerebral palsy (CP; OR = 0.91; p = 0.63), develop quotient < 70 (OR = 1.27; p = 0.17), visual impairment (OR = 1.08; p = 0.77), severe hearing impairment (OR = 1.28; p = 0.62) and death (OR = 0.98; p = 0.91) before three years of age. Conclusions: In this retrospective population-based study in Japan, HCA was not a risk factor for death, neurodevelopmental impairment and CP in VLBW three-year-old preterm infants.

A maternal mouse diet with moderately high-fat levels does not lead to maternal obesity but causes mesenteric adipose tissue dysfunction in male offspring☆

The impact of an increase in maternal fat consumption on fetal metabolic programming separately from maternal obesity remains unclear. The purpose of this study was to document the effect of in utero high-fat diet exposure on the development of metabolic syndrome characteristics in offspring. C57BL/6 female mice were fed either a control diet (10% fat) or a moderately high-fat (MHF) diet (45% fat) until delivery. All pups were fostered to mothers fed with the control diet. Pups were raised on the control diet and assessed until 35 weeks of age. The caloric intake from fat was significantly increased in the MHF dams compared with the control dams. There were no significant differences in the maternal weight at mating or at gestational Day 18 between the two groups. The MHF offspring did not become obese, but they developed hypertension and glucose intolerance. Moreover, the MHF offspring had significantly higher serum non-esterified fatty acid and triglyceride levels during the refeeding state following fasting as compared with the control offspring. Serum adiponectin levels were significantly lower, and the cell size of the mesenteric adipose tissue was significantly larger in the MHF offspring than in the control offspring. The mRNA levels of the proinflammatory macrophage markers in the mesenteric adipose tissue were significantly higher in the MHF offspring than those of the control offspring. These results suggest that in utero high-fat diet exposure causes hypertension and glucose intolerance resulting from mesenteric adipose tissue dysfunction in offspring, independently of maternal obesity.

Retrospective study of tadalafil for fetal growth restriction: Impact on maternal and perinatal outcomes

The aim of this retrospective study was to assess tadalafil treatment in pregnant women with fetal growth restriction (FGR) in terms of maternal and perinatal outcomes.

Isolated gestational proteinuria preceding the diagnosis of preeclampsia – an observational study

Some pregnant women develop significant proteinuria in the absence of hypertension. However, clinical significance of isolated gestational proteinuria (IGP) is not well understood. This study aimed to determine the prevalence of IGP in singleton pregnancies and the proportion of women with IGP who subsequently developed preeclampsia (IGP‐PE) among all PE cases.

High frequency of decreased antithrombin level in pregnant women with thrombosis

Venous thromboembolism (VTE) occurs frequently in pregnant women and is a significant cause of maternal death. Hemostatic abnormalities were examined in 18 pregnant women with thrombosis. We studied five families with congenital antithrombin (AT) deficiency, and two families with congenital protein C (PC) deficiency. One woman with PC deficiency showed protein S (PS) Tokushima. The AT activity levels were significantly lower at the onset of thrombosis in the pregnant women than during the stable state. The PS activity and antigen levels were also significantly lower at the onset of thrombosis. In the patients with congenital AT deficiency, AT activity was significantly low in the stable state and decreased further at the onset of thrombosis. Although AT levels were normal before pregnancy, they subsequently decreased and in two cases the patients required the administration of AT after pregnancy. Gene analysis revealed one family with AT Budapest, one family with AT Toyama, and three families with AT Glasgow. Additionally, there were one family with PC Tochigi and one family with combined heterozygous of PC deficiency and PS Tokushima. In conclusion, the deficiency of natural anticoagulants, especially AT, is an important cause of pregnancy-related VTE.