Kazuya Mimura

Silica and titanium dioxide nanoparticles cause pregnancy complications in mice

The increasing use of nanomaterials has raised concerns about their potential risks to human health. Recent studies have shown that nanoparticles can cross the placenta barrier in pregnant mice and cause neurotoxicity in their offspring, but a more detailed understanding of the effects of nanoparticles on pregnant animals remains elusive. Here, we show that silica and titanium dioxide nanoparticles with diameters of 70 nm and 35 nm, respectively, can cause pregnancy complications when injected intravenously into pregnant mice. The silica and titanium dioxide nanoparticles were found in the placenta, fetal liver and fetal brain. Mice treated with these nanoparticles had smaller uteri and smaller fetuses than untreated controls. Fullerene molecules and larger (300 and 1,000 nm) silica particles did not induce these complications. These detrimental effects are linked to structural and functional abnormalities in the placenta on the maternal side, and are abolished when the surfaces of the silica nanoparticles are modified with carboxyl and amine groups.

Placental Features of Chorioamnionitis Colonized With Ureaplasma Species in Preterm Delivery

Ureaplasma spp. is detected in the urogenital tract, including the vagina, cervix, chorioamnion, and placenta. Their colonization is associated with histologic chorioamnionitis (CAM), often observed in placentas from preterm delivery. We isolated Ureaplasma spp. from 63 preterm placentas among 151 specimens, which were delivered at <32 wk of gestation. Of the 63 placentas, 52 (83%) revealed CAM in cultures positive for Ureaplasma spp., however, CAM was observed only in 30% (26/88) of cultures negative for Ureaplasma spp. (p < 0.01). Colonization by Ureaplasma spp. was an independent risk factor for CAM (OR, 11.27; 95% CI, 5.09–24.98). Characteristic neutrophil infiltration was observed in the amnion and subchorion (bistratified pattern) in cultures positive for Ureaplasma spp. FISH analysis of CAM placenta with male infant pregnancy indicated that bistratified infiltrated neutrophils showed the XX karyotype and umbilical vein infiltrated neutrophils showed XY karyotype. The distribution of sulfoglycolipid, the receptor of Ureaplasma spp., was mainly detected in the amnion. Ureaplasmal urease D protein and ureB gene were both detected in the amnion, indicating direct colonization by Ureaplasma spp.

The activity of trabectedin as a single agent or in combination with everolimus for clear cell carcinoma of the ovary.

Purpose: The objective of this study was to evaluate the antitumor efficacy of trabectedin in clear cell carcinoma (CCC) of the ovary, which is regarded as an aggressive, chemoresistant, histologic subtype. Experimental Design: Using 6 human ovarian cancer cell lines (3 CCC and 3 serous adenocarcinomas), the antitumor effects of trabectedin were examined in vitro, and we compared its activity according to histology. We next examined the antitumor activity of trabectedin in both cisplatin-resistant and paclitaxel-resistant CCC cells in vitro. Then, the in vivo effects of trabectedin were evaluated using mice inoculated with CCC cell lines. Using 2 pairs of trabectedin-sensitive parental and trabectedin-resistant CCC sublines, we investigated the role of mTOR in the mechanism of acquired resistance to trabectedin. Finally, we determined the effect of mTOR inhibition by everolimus on the antitumor efficacy of trabectedin in vitro and in vivo. Results: Trabectedin showed significant antitumor activity toward chemosensitive and chemoresistant CCC cells in vitro. Mouse xenografts of CCC cells revealed that trabectedin significantly inhibits tumor growth. Greater activation of mTOR was observed in trabectedin-resistant CCC cells than in their respective parental cells. The continuous inhibition of mTOR significantly enhanced the therapeutic efficacy of trabectedin and prevented CCC cells from acquiring resistance to trabectedin. Conclusion: Trabectedin is a promising agent for CCC as a first-line chemotherapy and as a second-line treatment of recurrent CCC that had previously been treated with cisplatin or paclitaxel. Moreover, trabectedin combined with everolimus may be more efficacious for the management of CCC. Clin Cancer Res; 17(13); 4462–73. ©2011 AACR.

Nicotine restores endothelial dysfunction caused by excess sFlt1 and sEng in an in vitro model of preeclamptic vascular endothelium: a possible therapeutic role of nicotinic acetylcholine receptor (nAChR) agonists for preeclampsia.

OBJECTIVE In this study we tested the hypothesis that nicotine restores proangiogenic functions to endothelial cells pretreated with soluble fms-like tyrosine kinase 1 and/or soluble endoglin. STUDY DESIGN Wound healing assay and tube formation assay were performed using human umbilical vein endothelial cells treated with nicotine (10(-9) to 10(-6) M), and with various combinations of soluble fms-like tyrosine kinase 1 (100 ng/mL), soluble endoglin (100 ng/mL), and nicotine (10(-7) M). Enzyme-linked immunosorbent assay was performed to measure vascular endothelial growth factor, placental growth factor, and transforming growth factor-beta1 concentrations in the conditioned media treated with nicotine (10(-9) to 10(-6) M). RESULTS Nicotine significantly facilitated endothelial migration and tube formation. By contrast, soluble fms-like tyrosine kinase 1 and/or soluble endoglin suppressed these endothelial functions. Nicotine restored these soluble fms-like tyrosine kinase 1 and/or soluble endoglin-reduced endothelial functions. Placental growth factor, but not transforming growth factor-beta1, production was significantly stimulated by the presence of nicotine. Vascular endothelial growth factor was undetectable. CONCLUSION Our results suggest a possible mechanism for the protective effects of cigarette smoking against preeclampsia, thus proposing a therapeutic potential of nicotine or other nicotinic acetylcholine receptor agonists for preeclampsia.

Effects of Ureaplasma parvum lipoprotein multiple-banded antigen on pregnancy outcome in mice

Ureaplasma spp. are members of the family Mycoplasmataceae and have been considered to be associated with chorioamnionitis and preterm delivery. However, it is unclear whether Ureaplasma spp. have virulence factors related to these manifestations. The purpose of the present study was to determine whether the immunogenic protein multiple-banded antigen (MBA) from Ureaplasma parvum is a virulence factor for preterm delivery. We partially purified MBA from a type strain and clinical isolates of U. parvum, and also synthesized a diacylated lipopeptide derived from U. parvum, UPM-1. Using luciferase assays, both MBA-rich fraction MRF and UPM-1 activated the NF-κB pathway via TLR2. UPM-1 upregulated IL-1β, IL-6, IL-12p35, TNF-α, MIP2, LIX, and iNOS in mouse peritoneal macrophage. MRF or UPM-1 was injected into uteri on day 15 of gestation on pregnant C3H/HeN mice. The intrauterine MRF injection group had a significantly higher incidence of intrauterine fetal death (IUFD; 38.5%) than the control group (14.0%). Interestingly, intrauterine injection of UPM-1 caused preterm deliveries at high concentration (80.0%). In contrast, a low concentration of UPM-1 induced a significantly higher rate of fetal deaths (55.2%) than the control group (14.0%). The placentas of the UPM-1 injection group showed neutrophil infiltration and increased iNOS protein expression. Our data indicate that MBA from the clinical isolate of U. parvum is a potential virulence factor for IUFD and preterm delivery in mice and that the N-terminal diacylated lipopeptide is essential for the initiation of inflammation.

Oxidative stress-induced S100B protein from placenta and amnion affects soluble Endoglin release from endothelial cells.

Oxidative stress with elevated intracellular Ca(2+) concentration as well as endothelial dysfunction is a component of pre-eclampsia. Our aim was to investigate the oxidative stress-dependent expression of Endoglin and Ca(2+)-binding S100B protein from villous and amniotic tissue cultures, and to assess sEng expression from S100B protein-stimulated endothelial cells. We initially examined Endoglin and Hydroxy-nonenal-(HNE)-modified proteins in the placentas and amnion obtained from women with pre-eclampsia (n = 8), and healthy controls (n = 8) by immunohistochemistry. To examine oxidative stress and the S100B protein effect on sEng expression from endothelial cells, normal villous and amniotic tissue cultures were stimulated by 4-HNE, sodium fluoride and xanthine/xanthine oxidase, whereas human umbilical vein endothelial cell cultures were treated with S100B protein in a dose- and time-dependent manner at 37 degrees C in an environment of 95% air and 5% of CO(2). Culture supernatants were assessed using ELISA. Cell viability was determined using MTS assay. The concentrations of sEng and S100B protein were significantly increased in the villous and amniotic tissue culture supernatants under oxidative stress. S100B protein-stimulated endothelial cells released sEng into conditioned media with a significantly higher expression levels at a concentration of 200 pM-20 nM S100B by 2 h, whereas treated with 200 nM of S100B endothelial cells significantly expressed sEng by 12 h and stimulated the cell proliferation by the same period of time. Our findings show that oxidative stress affects sEng and S100B protein expression from villous and amniotic tissues, and picomolar and low nanomolar concentrations of S100B protein significantly up-regulate sEng release from endothelial cells leading to endothelial dysfunction.

Ceftriaxone preconditioning confers neuroprotection in neonatal rats through glutamate transporter 1 upregulation.

Objective: This study investigated the hypothesis that ceftriaxone preconditioning ameliorates brain damage in neonatal animals through glutamate transporter 1 (GLT-1) upregulation. Study design: Sprague Dawley rats were pretreated with ceftriaxone, erythromycin, minocycline, or saline for 5 consecutive days starting from postnatal day 2 (P2), and GLT-1/glutamate-aspartate transporter (GLAST) messenger RNA (mRNA) and protein levels were examined in the P7 brains. After ceftriaxone or saline preconditioning, the P7 rats underwent hypoxic-ischemic (H-I) procedure or sham operation. One week after the procedure (P14), hematoxylin-eosin staining, microtubule-associated protein 2 (MAP-2) immunostaining, and transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay were used to examine neuronal damage and possible neurotoxicity. Results: Repeated ceftriaxone injections significantly increased GLT-1 mRNA and protein levels but not GLAST. Following such treatment and H-I procedure, the MAP-2-positive area increased and TUNEL-positive cells decreased. Conclusion: Antenatal ceftriaxone may help to provide neuroprotection in the immature brain and become a new prophylactic strategy to reduce neonatal encephalopathy in clinical perinatal medicine.

Nicotine suppresses interleukin-6 production from vascular endothelial cells: a possible therapeutic role of nicotine for preeclampsia.

Normal pregnancy is the controlled state of inflammation and this systemic inflammatory response is reported to be more intense in preeclampsia. The current study tested the hypothesis that maternal serum stimulates interleukin 6 (IL-6) production from endothelial cells and that nicotine inhibits these effects. Human umbilical vein endothelial cells (HUVECs) were incubated with or without 0.5% serum from healthy pregnant women at term (n = 5) and treated with or without nicotine (10-9 to 10-6 mol/L) in the presence of 0.5% serum. Cell survival was determined by colorimetric assay. Interleukin 6 concentration and nuclear transcription factor kappa B (NF-kB) activities were determined by enzyme-linked immunosorbent assay (ELISA)-based method. Interleukin 6 production by endothelial cells was significantly stimulated in the presence of maternal serum. Nicotine significantly preserved cell survival and suppressed IL-6 production from endothelial cells. Nicotine also significantly inhibited NF-kB activation in endothelial cells. Nicotine inhibited inflammatory reaction through NF-kB suppression in vitro model of maternal vascular endothelium, and this effect may be one of the explanations for the reduced risk of preeclampsia in smokers.

Three-dimensional sonography in the differential diagnosis of interstitial, angular, and intrauterine pregnancies in a septate uterus.

Interstitial, angular, and cornual pregnancies and intrauterine pregnancies in an anomalous uterus are separate entities, and the impact of each condition on obstetric outcomes is completely different. However, there is considerable confusion in understanding and managing the natural course of each condition due to a lack of uniform terminology. The single most important factor for differentiating these types of pregnancies is to make an early diagnosis. The differences between interstitial, angular, and cornual pregnancies on 2‐dimensional (2D) sonography are subtle. Although magnetic resonance imaging can be used to differentiate these conditions, it is not preferred as the initial assessment tool because of its limited availability and cost‐effectiveness. Three‐dimensional (3D) sonography has the advantage of providing views of the uterus that cannot be obtained with conventional 2D sonography. We describe 3 cases of interstitial, angular, and intrauterine pregnancies in a septate uterus that were clearly differentiated by 3D sonography. We demonstrate the differences in diagnostic imaging findings and emphasize the importance of 3D sonography in differentiating these entities.

Maternal arterial stiffness in normotensive pregnant women who subsequently deliver babies that are small for gestational age.

OBJECTIVE To assess the association between maternal arterial stiffness and delivery of a baby that is small for gestational age (SGA) in normotensive pregnant women. STUDY DESIGN Pulse wave analyses were performed to assess maternal arterial stiffness at 26-33 weeks of gestation in 40 normotensive women who subsequently delivered SGA babies (SGA group) and 111 normotensive women who delivered babies with normal growth (control group). RESULTS Central systolic pressure (CSP), augmentation index (AIx) and AIx at a heart rate of 75 beats/min (AIx-75) were significantly higher in the SGA group compared with the control group, but this was not the case for brachial systolic pressure, brachial diastolic pressure or brachial pulse pressure. Birth weight was significantly correlated with CSP (r=-0.26, p<0.01), AIx (r=-0.33, p<0.01) and AIx-75 (r=-0.27, p<0.01), but not with brachial systolic pressure, brachial diastolic pressure or brachial pulse pressure. CONCLUSION Increased arterial stiffness may be involved, in part, in the pathogenesis of SGA in normotensive women, suggesting an association between fetal growth and maternal endothelial function. Pulse wave analysis may be a clinically applicable method for assessment of maternal arterial stiffness, and may be more relevant to intrauterine fetal growth than conventional brachial blood pressure.