Inflammatory, metabolic, and sex-dependent gene-regulatory dynamics of microglia and macrophages in neonatal hippocampus after hypoxia-ischemia.

Neonatal hypoxia-ischemia (HI) is a major cause of perinatal death and long-term disabilities worldwide. Post-ischemic neuroinflammation plays a pivotal role in HI pathophysiology. In the present study, we investigated the temporal dynamics of microglia (CX3CR1GFP/+) and infiltrating macrophages (CCR2RFP/+) in the hippocampi of mice subjected to HI at postnatal day 9. Using inflammatory pathway and transcription factor (TF) analyses, we identified a distinct post-ischemic response in CCR2RFP/+ cells characterized by differential gene expression in sensome, homeostatic, matrisome, lipid metabolic, and inflammatory molecular signatures. Three days after injury, transcriptomic signatures of CX3CR1GFP/+ and CCR2RFP/+ cells isolated from hippocampi showed a partial convergence. Interestingly, microglia-specific genes in CX3CR1GFP/+ cells showed a sexual dimorphism, where expression returned to control levels in males but not in females during the experimental time frame. These results highlight the importance of further investigations on metabolic rewiring to pave the way for future interventions in asphyxiated neonates.

Safety trial of tadalafil administered for the treatment of preeclampsia.

Purpose: The aim of this study is to evaluate the safety of clinical usage of tadalafil in women with preeclampsia.Materials and methods: Maternal, fetal, and neonatal adverse events were closely examined in eight preeclampsia patients receiving tadalafil treatment.Results: There were no maternal adverse events associated with 10 mg/day of tadalafil. Even at 20 mg/day, only grade 1 headaches in two cases and grade 1 palpitation in one case were observed, which resolved spontaneously within 3 days. At a dose of 40 mg/day, there was only one case of grade 1 headache. All these adverse events were grade 1 and spontaneously resolved within 3 days. There were no fetal adverse events. All observed neonatal adverse events were thought to be caused by prematurity and not related to tadalafil.Conclusion: This study shows that tadalafil treatment for preeclampsia is deemed sufficiently tolerable. Although there was a dose-dependent increase in maternal adverse events, all the adverse events were mild and deemed to be safe for the mother and fetus at all dosages.

Tadalafil treatment in mice for preeclampsia with fetal growth restriction has neuro-benefic effects in offspring through modulating prenatal hypoxic conditions.

We have demonstrated that tadalafil facilitates fetal growth in mice with L-NG-nitroarginine methyl ester (L-NAME)-induced preeclampsia (PE) with fetal growth restriction (FGR). Tadalafil is a selective phosphodiesterase 5 inhibitor that dilates the maternal blood sinuses in the placenta, thereby facilitating the growth of the fetus. The purpose of this study was to investigate the effects of tadalafil treatment for PE and FGR on the developing brain in FGR offspring using an L-NAME-induced mouse model of PE with FGR. A control group of dams received carboxymethylcellulose (CMC). L-NAME-treated groups received L-NAME dissolved in CMC from 11 days post coitum (d.p.c.). The L-NAME-treated dams were divided into two subgroups 14 d.p.c. One subgroup continued to receive L-NAME. The other subgroup received L-NAME with tadalafil suspended in CMC. Tadalafil treatment for PE with FGR reduced the expression of hypoxia-inducible factor-2α in the placenta and in the brain of the FGR fetus. Moreover, tadalafil treatment in utero shows improved synaptogenesis and myelination in FGR offspring on postnatal day 15 (P15) and P30. These results suggest that tadalafil treatment for PE with FGR not only facilitates fetal growth, but also has neuroprotective effects on the developing brain of FGR offspring through modulating prenatal hypoxic conditions.

Cardiac function and tadalafil used for treating fetal growth restriction in pregnant women without cardiovascular disease.

BACKGROUND: The aim of the present study was to evaluate tadalafil for the treatment of fetal growth restriction (FGR) and the cardiac function in pregnant women without cardiovascular disease who used tadalafil for this reason. MATERIALS AND METHODS: We examined nine pregnant women without cardiovascular disease who were using tadalafil to treat FGR. Maternal heart rate, systolic blood pressure (BP), and echocardiographic findings were assessed before and after tadalafil use. RESULTS: Diastolic BP was lower after compared to that before using tadalafil, but the difference was not significant. Echocardiographic findings were not significantly different before and after tadalafil use. CONCLUSIONS: Tadalafil did not adversely affect pregnant women without cardiovascular disease and was considered acceptable for use since it did not affect the mother's cardiac function.

Placental growth factor as a predictor of the efficacy of tadalafil treatment for fetal growth restriction.

Purpose: We recently demonstrated the efficacy of tadalafil treatment for fetal growth restriction (FGR). This study aimed to evaluate the utility of serum placental growth factor (PlGF) level for predicting the efficacy of tadalafil for the treatment of FGR. Materials and methods: The correlations between serum level of PlGF and fetal growth velocity were retrospectively assessed in nine pregnant women receiving tadalafil for FGR before 30 weeks' gestation. Results: Median gestational age was 26 weeks (range 26-28 weeks), and median deviation of estimated fetal weight from standard weight was -2.1 standard deviations (SD) (-2.2 to -1.9 SD) at the beginning of tadalafil treatment. The median serum PlGF level was 227 pg/ml (40.2-427.0 pg/ml) before tadalafil treatment and 278 pg/ml (66.2-729.5 pg/ml) more than 2 weeks after initiation of tadalafil treatment (median gestational week at measurement of PlGF after treatment, 33 weeks [28-33 weeks]). The median fetal growth velocity from enrollment to birth was 17.5 g/day (12.1-20.3 g/day). Maternal serum PlGF levels were increased after tadalafil treatment in all nine cases (median increase in PlGF, 73.1 pg/ml [26.0-281.5 pg/ml]). Notably, maternal serum PlGF level before tadalafil treatment significantly correlated with fetal growth velocity (R2 = 0.63, p < .01). Conclusions: Tadalafil treatment may increase maternal serum PlGF levels. Our results suggest that maternal serum PlGF levels can be used as a predictor of the efficacy of tadalafil treatment for FGR.

Management of fetal growth restriction using the contraction stress test: a case-control study.

Purpose: Fetal growth restriction (FGR) is a concerning health issue. However, studies on FGR management are limited due to its rarity. We aimed to evaluate the efficacy of the contraction stress test (CST) for FGR management. Materials and methods: A case-control retrospective study design. Our institute innovated CST in FGR management in 2017. We included women in their 33rd-40th week of pregnancy with a diagnosis of FGR and retrospectively divided them into groups: the CST group (FGR management with CST) and no CST group (FGR management without CST) before and after CST development. Neonatal outcome, pH, and pO2 of umbilical artery (UA) were compared between the two groups. Results: No significant differences in the rate of birth weight, Apgar score <7 (5 minutes), neonatal death, hospitalization to newborn childhood intensive care unit (NICU), and UA pH were found between groups. Average UA pH was 7.29 ± 0.05 and 7.29 ± 0.04 in the CST and no CST groups, respectively (p = .864). Average UA pO2 values were 21.1 ± 8.6 and 15.7 ± 5.0 mmHg in the CST and no CST groups, respectively (p = .016), showing significant differences. Conclusions: Neonatal outcomes and UA pH were slightly different between the groups managed with and without CST. However, UA pO2 values significantly differed between the groups. For FGR management, the use of a CST may allow for early intervention before fetal acidemia and acidosis. For establishing the effects of a CST for FGR management, analysis including several cases and investigation of long-term outcomes of newborn infants is necessary.

TADAFER II: Tadalafil treatment for fetal growth restriction - a study protocol for a multicenter randomised controlled phase II trial.

INTRODUCTION: There is no proven therapy to reverse or ameliorate fetal growth restriction (FGR). Sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, has been reported to potentially play a therapeutic role in FGR, but this has not been established. Tadalafil is also a selective PDE5 inhibitor. We have demonstrated the efficacy of tadalafil against FGR along with short-term outcomes and the feasibility of tadalafil treatment. Based on the hypothesis that tadalafil will safely increase the likelihood of increased fetal growth in FGR, we designed this phase II study to prospectively evaluate the efficacy and safety of tadalafil against FGR. METHODS AND ANALYSIS: This study is a multicentre, randomised controlled phase II trial. A total of 140 fetuses with FGR will be enrolled from medical centres in Japan. Fetuses will be randomised to receive either the conventional management for FGR or a once-daily treatment with 20 mg of tadalafil along with the conventional management until delivery. The primary endpoint is fetal growth velocity from the first day of the protocol-defined treatment to birth (g/day). To minimise bias in terms of fetal baseline conditions and timing of delivery, a fetal indication for delivery was established in this study. The investigator will evaluate fetal baseline conditions at enrolment and will decide the timing of delivery based on this fetal indication. Infants will be followed up for development until 1.5 years of age. ETHICS AND DISSEMINATION: This study was approved by the Institutional Review Board of Mie University Hospital and each participating institution. Our findings will be widely disseminated through peer-reviewed publications. TRIAL REGISTRATION NUMBER: UMIN000023778.

Amniotic Fluid Natriuretic Peptide Levels in Fetuses With Congenital Heart Defects or Arrhythmias.

BACKGROUND: We have previously demonstrated that umbilical cord plasma natriuretic peptide (NP) levels reflect the severity of heart failure (HF) in fetuses with congenital heart defects (CHD). The aim of this study was to evaluate the significance of amniotic fluid (AF) NP levels in the assessment of HF in fetuses with CHD or arrhythmia. Methods and Results: This was a prospective observational study at a tertiary pediatric cardiac center. A total of 95 singletons with CHD or arrhythmia, and 96 controls from 2012 to 2015 were analyzed. AF concentrations of atrial NP (ANP), B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) at birth were compared with ultrasonographic assessment of fetal HF using the cardiovascular profile (CVP) score. Multivariate analysis showed that a CVP score ≤5 and preterm birth are independently associated with high AF NT-proBNP levels. AF NT-proBNP levels of fetuses with CHD or arrhythmia inversely correlated with CVP score (P for trend <0.01). In contrast, AF concentrations of ANP and BNP were extremely low, and it was difficult to assess the degree of fetal HF based on them. CONCLUSIONS: AF NT-proBNP concentrations increase in stepwise fashion with the severity of HF in fetuses with CHD or arrhythmia; it was the optimal NP for assessing the fetal HF.

Tadalafil Improves L-NG-Nitroarginine Methyl Ester-Induced Preeclampsia With Fetal Growth Restriction-Like Symptoms in Pregnant Mice.

BACKGROUND: We investigated the efficacy and mechanisms of tadalafil, a selective phosphodiesterase 5 inhibitor, in treating preeclampsia (PE) with fetal growth restriction (FGR) using L-NG-nitroarginine methyl ester (L-NAME)-induced PE with FGR in pregnant mice as our experimental model. METHODS: C57BL/6 mice were divided into 2 groups 11 days postcoitum (d.p.c.). A control group of dams (C dam) received 0.5% carboxymethylcellulose (CMC). A L-NAME-treated group received 1 mg/ml L-NAME dissolved in CMC. The L-NAME-treated dams were divided into 2 subgroups 13 d.p.c. One subgroup continued to receive L-NAME (L dams). The other subgroup received L-NAME with 0.08 mg/ml tadalafil suspended in CMC (TL dams). Maternal systolic blood pressure (SBP) and proteinuria were assessed 16 d.p.c. Fetal weight was recorded, and placentas and maternal kidneys were collected 17 d.p.c. RESULTS: Maternal SBP, proteinuria, and fetal weight were improved for TL dams compared to L dams. The placental concentration of placental growth factor (PlGF) was higher for TL dams than for the C and L dams. The placental maternal blood sinuses of L dams were narrower than those of C dams, but those of TL dams improved to a similar width as C dams. Glomerular oxidative stress was ameliorated in TL dams compared to L dams. CONCLUSIONS: Tadalafil dilates the placental maternal blood sinuses, which leads to increase PlGF production, and contributes to facilitate fetal growth and improve maternal SBP. Moreover, tadalafil ameliorates glomerular damage by reducing oxidative stress. These results suggest that tadalafil is a candidate for treatment of PE with FGR.

Safety and dose-finding trial of tadalafil administered for fetal growth restriction: A phase-1 clinical study.

AIM: We designed a safety and dose-finding trial of tadalafil administered for fetal growth restriction (FGR). METHODS: Three cases were initially commenced on 10 mg/day and monitored for major adverse events. Should a major adverse event be observed in one or more of the three cases, an examination into its relation with tadalafil would be conducted by a safety evaluation committee. If one or more of these new cases exhibited the same adverse event, the trial would be stopped completely. If there were no harmful side-effects, the trial would be extended to three cases at 20 mg/day, and the protocol would continue as in the 10-mg/day dose. The 40-mg/day dosage was tried in six cases as the dosage was considered to be high. RESULTS: The study population consisted of pregnant women with FGR. Maternal adverse events in all doses were recorded as least one grade 1 adverse events, as tadalafil was considered acceptable from the viewpoint of the mothers. However, a dose of 40 mg/day increased the number of grade 1 adverse events. The only fetal adverse event was a case of intrauterine fetal death related to the velamentous insertion of the umbilical cord. Neonatal adverse events showed no correlation to tadalafil dose, but were found more frequently in preterm births and, therefore, were correlated to infant prematurity. CONCLUSION: This safety and dose-finding trial showed that tadalafil had a favorable safety profile for pregnant women and fetuses with FGR.

Treatment using tadalafil for severe pre-eclampsia with fetal growth restriction.

For severe pre-eclampsia (PE) with fetal growth restriction (FGR), the only effective treatment is early delivery of the placenta. Clinicians are often forced to end the pregnancy because of maternal indications. We report a case of severe PE with FGR in which the PE was temporarily improved and pregnancy successfully prolonged with tadalafil, a phosphodiesterase 5 inhibitor. A 35-year-old primigravid woman presented at 27 3/7 weeks of gestation with severe PE and FGR. After commencing tadalafil administration, biochemical and angiogenic markers improved. Thereafter, hypertension and proteinuria temporarily improved. Importantly, the pregnancy was prolonged by 14 days after the initiation of tadalafil administration. Tadalafil may be a novel treatment for severe PE with FGR to prolong pregnancy.

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

AIM: 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. METHODS: We retrospectively analyzed 11 Japanese singleton pregnant women with FGR who received tadalafil along with conventional management for FGR at Mie University Hospital from July 2015 to February 2016 (tadalafil group). These women were matched for maternal age, parity, gestational age, and estimated fetal weight at enrollment with 14 singleton pregnant women who received only the conventional management for FGR in 2014 (conventional management group). The conventional management for FGR was performed according to guidelines for obstetric practice in Japan. RESULTS: Both birthweight and fetal growth velocity from enrollment to birth were significantly higher in the tadalafil group than in the conventional management group. The cesarean delivery rate was approximately twofold higher in the conventional management group than in the tadalafil group. Importantly, cesarean section due to non-reassuring fetal status was performed in seven pregnant women in the conventional management group (58.3%) but in none in the tadalafil group (P < 0.05, chi-squared test). CONCLUSIONS: Tadalafil may improve perinatal outcome in FGR by modulating fetal growth through maintenance or improvement of fetal well-being.

Early-onset fetal growth restriction treated with the long-acting phosphodiesterase-5 inhibitor tadalafil: a case report.

BACKGROUND: Severe early-onset fetal growth restriction occurs in 0.4 % of all pregnancies, and the prognoses of these patients are dismal. Severely growth-restricted fetuses (far below 500 g) are thought to be nonviable. Since there have not been effective treatments for such fetal patients, obstetricians have simply tried to identify the optimal timing for their delivery. There are a few reports suggesting that the phosphodiesterase type 5 inhibitor sildenafil has some limited beneficial effects on fetal growth, but there are no such reports on tadalafil, another derivative phosphodiesterase type 5 inhibitor which has a much longer half-life than sildenafil. Here we present a case in which the administration of tadalafil to the mother revived the arrested growth and severe oligohydramnios of the very prematurely growth-restricted fetus. CASE PRESENTATION: We describe a case of early-onset fetal growth restriction with oligohydramnios in a 41-year-old primigravida Japanese woman who was treated with tadalafil (20-mg tablet daily) from 22 weeks' gestational age. Ten days after the initiation of the tadalafil therapy, the amniotic fluid level rose and the weight of the fetus began to increase. A 1024-g baby boy was delivered by cesarean at 32 weeks' gestation. The z-score for fetal head circumference had increased from -2.2 to -1.2, whereas the z-score of the femur legth was decreased to -4.3, indicating that tadalafil preferentially increased the blood flow to important organs. CONCLUSIONS: We achieved two positive results by administering tadalafil to the mother carrying a severely growth-restricted fetus with oligohydramnios. First, the z-scores of head circumference and abdominal circumference had at first declined but started to rise after the tadalafil administration. Second, the amniotic fluid, which was emptied before the tadalafil treatment, recovered to normal range with this treatment. Tadalafil administration to mothers could be a promising therapy to reverse severe fetal growth restriction and oligohydramnios.

Cranial irradiation induces transient microglia accumulation, followed by long-lasting inflammation and loss of microglia.

The relative contribution of resident microglia and peripheral monocyte-derived macrophages in neuroinflammation after cranial irradiation is not known. A single dose of 8 Gy was administered to postnatal day 10 (juvenile) or 90 (adult) CX3CR1GFP/+ CCR2RFP/+ mouse brains. Microglia accumulated in the subgranular zone of the hippocampal granule cell layer, where progenitor cell death was prominent. The peak was earlier (6 h vs. 24 h) but less pronounced in adult brains. The increase in juvenile, but not adult, brains was partly attributed to proliferation. Microglia numbers then decreased over time to 39% (juvenile) and 58% (adult) of controls 30 days after irradiation, largely as a result of cell death. CD68 was expressed in 90% of amoeboid microglia in juvenile hippocampi but only in 9% of adult ones. Isolated hippocampal microglia revealed reduced CD206 and increased IL1-beta expression after irradiation, more pronounced in juvenile brains. CCL2 and IL-1 beta increased after irradiation, more in juvenile hippocampi, and remained elevated at all time points. In summary, microglia activation after irradiation was more pronounced, protracted and pro-inflammatory by nature in juvenile than in adult hippocampi. Common to both ages was long-lasting inflammation and the absence of monocyte-derived macrophages.

Resident microglia, rather than blood-derived macrophages, contribute to the earlier and more pronounced inflammatory reaction in the immature compared with the adult hippocampus after hypoxia-ischemia.

The mechanisms of neuronal injury after hypoxia-ischemia (HI) are different in the immature and the adult brain, but microglia activation has not been compared. The purpose of this study was to phenotype resident microglia and blood-derived macrophages in the hippocampus after HI in neonatal (postnatal day 9, P9) or adult (3 months of age, 3mo) mice. Unilateral brain injury after HI was induced in Cx3cr1(GFP/+) Ccr2(RFP/+) male mice on P9 (n = 34) or at 3mo (n = 53) using the Vannucci model. Resident microglia (Cx3cr1-GFP+) proliferated and were activated earlier after HI in the P9 (1-3 days) than that in the 3mo hippocampus, but remained longer in the adult brain (3-7 days). Blood-derived macrophages (Ccr2-RFP+) peaked 3 days after HI in both immature (P9) and adult (3mo) hippocampi but were twice as frequent in adult brains, 41% vs. 21% of all microglia/macrophages. CCL2 expression was three times higher in the P9 hippocampi, indicating that the proinflammatory response was more pronounced in the immature brain after HI. This corresponded well with the higher numbers of galectin-3-positive resident microglia in the P9 hippocampi, but did not correlate with CD16/32- or CD206-positive resident microglia or blood-derived macrophages. In conclusion, resident microglia, rather than infiltrating blood-derived macrophages, proliferate and are activated earlier in the immature than in the adult brain, but remain increased longer in the adult brain. The inflammatory response is more pronounced in the immature brain, and this correlate well with galectin-3 expression in resident microglia.

Postnatal weight gain induced by overfeeding pups and maternal high-fat diet during the lactation period modulates glucose metabolism and the production of pancreatic and gastrointestinal peptides.

The impact of rapid weight gain on glucose metabolism during the early postnatal period remains unclear. We investigated the influence of rapid weight gain under different nutritional conditions on glucose metabolism, focusing on the production of pancreatic and gastric peptides. On postnatal day (PND) 2, C57BL/6N pups were divided into three groups: control (C) pups whose dams were fed a control diet (10%kcal fat) and nursed 10 pups each; maternal high-fat diet (HFD) pups whose dams were fed an HFD (45%kcal fat) and nursed 10 pups each; and overfeeding (OF) pups whose dams were fed the control diet and nursed 4 pups each. Data were collected on PND 7, 14 and 21. The body weight gains of the HFD and OF pups were 1.2 times higher than that of the C pups. On PND 14, the HFD pups had higher blood glucose levels, but there were no significant differences in serum insulin levels between the HFD and C pups. The OF pups had higher blood glucose and serum insulin levels than that of the C pups. Insulin resistance was found in the HFD and OF pups. On PND 14, the content of incretins in the jejunum was increased in the OF pups, and acyl ghrelin in the stomach was upregulated in the HFD and OF pups. These results suggest that neonatal weight gain induced by overfeeding pups and maternal high-fat diet during the early postnatal period modulates the insulin sensitivity and the production of pancreatic and gastrointestinal peptides.

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.

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.

Overexpression of thioredoxin-1 reduces oxidative stress in the placenta of transgenic mice and promotes fetal growth via glucose metabolism.

Oxidative stress occurs where there is an imbalance between the production and scavenging of free radicals. Pregnancy per se is a state of oxidative stress due to the increased metabolic activity of placental mitochondria and reduced scavenging ability of antioxidant systems. Overproduction of reactive oxygen species may be associated with impaired fetal growth. However, the physiological influence of antioxidant systems on fetal growth is not well understood. In this study we assessed the effects of antioxidant systems on fetal growth using human thioredoxin (hTRX)-1 overexpressing transgenic (Tg) mice. Tg or C57BL/6 [wild-type (WT)] male mice were mated with WT female mice, and dams were killed to obtain the fetuses and placentas on gestational d 15. Tg fetuses were significantly heavier than WT fetuses, whereas placental weight did not differ significantly between the two groups. Immunohistochemically, hTRX-1 was localized to the nuclei of labyrinthine trophoblasts in Tg mice. In addition, placental expression of 8-hydroxy-2'-deoxyguanosine, which reflects DNA damage caused by oxidative stress, was reduced in Tg mice compared with WT mice. Placental expression of glucose transporter-1 mRNA and protein was significantly higher in Tg mice than WT mice, whereas no significant differences were observed for glucose transporter-3, IGF, and IGF-binding protein mRNA expression. These results suggest that placental and/or systemic antioxidant systems can influence fetal growth. In particular, increased hTRX-1 activity and the resulting modified placental redox state may play an important role in fetal growth by increasing the availability of glucose.