Dalei Zhang

Maternal exposure to di-(2-ethylhexyl) phthalate disrupts placental growth and development in pregnant mice.

Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and widely dispersed in the environment. DEHP exposure reduces embryo implantations, increases embryonic loss, and decreases fetal body weights. However, no detailed information is available about the effect of DEHP on the placentation during pregnancy. Thus, our aim was to explore the effect of DEHP on the growth and development of placenta in vivo. Mice were administered DEHP by gavages at 125, 250, 500 mg/kg/day from gestational days (GD) 1 until sacrifice. Results showed that DEHP treatment significantly reduced the weight of placenta at GD 13. Histopathologically, in DEHP-treated group, the ectoplacental cones significantly became smaller at GD9, and total area of placenta and area of spongiotrophoblast were significantly reduced at GD 13. Expression levels of Ascl2, Esx1 and Fosl1 mRNA dramatically decreased in DEHP-treated placenta at GD 13. DEHP administration disrupted labyrinth vascularization of placentas, and inhibited proliferation and induced apoptosis of placenta by the activation of caspase-3 and -8, up-regulation of Bax and down-regulation of Bcl-2 mRNA and protein at GD 13. In conclusion, these results suggest that adverse pregnancy outcomes including low birth-weight and pregnancy loss exposed to DEHP are possibly mediated, at least in part, via the suppression of placental growth and development.

Involvement of Oxidative Stress and Inflammation in Liver Injury Caused by Perfluorooctanoic Acid Exposure in Mice

Perfluorooctanoic acid (PFOA) is widely present in the environment and has been reported to induce hepatic toxicity in animals and humans. In this study, mice were orally administered different concentrations of PFOA (2.5, 5, or 10 mg/kg/day). Histological examination showed that the exposure to PFOA for 14 consecutive days led to serious hepatocellular injury and obvious inflammatory cell infiltration. In addition, malondialdehyde formation and hydrogen peroxide generation, indicators of oxidative stress, were significantly induced by PFOA treatment in the liver of mice. Furthermore, hepatic levels of interleukin-6, cyclooxygenase-2, and C-reactive protein, markers of inflammatory response, were markedly increased by exposure to PFOA in mice. These results demonstrated that PFOA-induced hepatic toxicity may be involved in oxidative stress and inflammatory response in mice.

Involvement of NRF2 in Perfluorooctanoic Acid-Induced Testicular Damage in Male Mice

ABSTRACT Perfluorooctane acid (PFOA) is a hazardous environmental pollutant that has been reported to exert adverse effects on animal and human health. In this study, male mice were orally administered different concentrations of PFOA (2.5, 5, or 10 mg/kg/day) to evaluate the reproductive toxicity. Exposure to PFOA for 14 consecutive days obviously disrupted seminiferous tubules and reduced sperm count. The highest concentration of PFOA (10 mg/kg/day) caused growth retardation and diminished absolute testis weight. Furthermore, PFOA treatment significantly increased the generation of oxidative stress indicators malondialdehyde and hydrogen peroxide, decreased the expression of transcription factor NRF2, and inhibited the activities of antioxidant enzymes superoxide dismutase and catalase in the testis. Moreover, PFOA exposure up-regulated p-p53 and BAX expression and down-regulated BCL-2 expression in the testis. These results indicated that PFOA-induced male reproductive disorders might be involved in developmental impairment and inhibition of NRF2-mediated antioxidant response in the testis of mice.

Expression and regulation of androgen receptor in the mouse uterus during early pregnancy and decidualization.

The androgen receptor (AR) is a ligand‐activated transcription factor that is important for both the male and female reproductive systems. The expression and regulation of AR in the uterine endometrium during early pregnancy and decidualization remain relatively under‐investigated, so we sought to immunohistochemically examine the spatiotemporal expression of AR in mouse uteri during the peri‐implantation period as well as in response to specific steroid hormones. AR protein was found in the nuclei of uterine stromal cells starting on pregnancy Days 1 and 2, with its abundance increasing on Days 3 and 4. From pregnancy Days 5 to 9, however, the expression of AR markedly declined in stromal zones of uteri. No signal was detected in the decidualized cells surrounding the site of embryo implantation; moreover, no AR immunostaining was observed in decidualized uterine cells in an artificial oil‐induced model of decidualization. Progesterone significantly inhibited AR protein expression, whereas estrogen dramatically elevated AR abundance in the stroma of ovariectomized mouse uteri. Taken together, our results are the first to demonstrate that decidualization and progesterone significantly inhibited the AR protein expression in vivo, whereas estrogen increased AR protein levels in the stromal cells of mouse uteri. These responses might be advantageous for the proliferation and differentiation of uterine stroma and for embryo implantation during early pregnancy. Mol. Reprod. Dev. 82: 898–906, 2015.

Maternal exposure to perfluorooctanoic acid inhibits luteal function via oxidative stress and apoptosis in pregnant mice

Perfluorooctanoic acid (PFOA) is a synthetic perfluorinated compound, which has been reported to exert adverse effect on the pregnancy. However, whether it is associated with alteration of luteal function remains unknown. Mice were administered PFOA by gavage from gestational days (GD) 1-7 or 13. PFOA treatment did not significantly affect numbers of embryo implantation. Nevertheless, on GD 13, 10mg/kg PFOA treatment significantly increased numbers of resorbed embryo. Furthermore, PFOA exposure markedly reduced serum progesterone levels but did not affect estradiol levels. Treatment also showed concomitant decreases in transcript levels for key steroidogenic enzymes, and reduced numbers and sizes of corpora lutea. In addition, PFOA administration inhibited activities of superoxide dismutase and catalase, and increased generation of hydrogen peroxide and malondialdehyde, and down-regulated level of Bcl-2 and up-regulated p53 and BAX proteins. In conclusion, PFOA exposure significantly inhibits luteal function via oxidative stress and apoptosis in pregnant mice.

Inhibitory modulation of CART peptides in accumbal neuron through decreasing interaction of CaMKIIα with dopamine D3 receptors.

Previous studies in rats have shown that microinjections of cocaine- and amphetamine-regulated transcript (CART) peptide into the nucleus accumbens (NAc; the area of the brain that mediates drug reward and reinforcement) attenuate the locomotor effects of psychostimulants. CART peptide has also been shown to induce decreased intracellular concentrations of calcium (Ca(2+)) in primary cultures of hippocampus neurons. The purpose of this study was to characterize the interaction of Ca(2+)/calmodulin-dependent kinases (CaMKIIα) with dopamine D3 (D3) receptors (R) in primary cultures of accumbal neurons. This interaction is involved in inhibitory modulation of CART peptides. In vitro, CART (55-102) peptide (0.1, 0.5 or 1μM) was found to dose-dependently inhibit K(+) depolarization-elicited Ca(2+) influx and CaMKIIα phosphorylation in accumbal neurons. Moreover, CART peptides were also found to block cocaine (1μM)-induced Ca(2+) influx, CaMKIIα phosphorylation, CaMKIIα-D3R interaction, and CREB phosphorylation. In vivo, repeated microinjections of CART (55-102) peptide (2μg/1μl/side) into the NAc over a 5-day period had no effect on behavioral activity but blocked cocaine-induced locomotor activity. These results indicate that D3R function in accumbal neurons is a target of CART (55-102) peptide and suggest that CART peptide by dephosphorylating limbic D3Rs may have potential as a treatment for cocaine abuse.

Moxibustion relieves visceral hyperalgesia via inhibition of transient receptor potential vanilloid 1 (TRPV1) and heat shock protein (HSP) 70 expression in rat bone marrow cells

Objective To investigate the effects of moxibustion on visceral hyperalgesia (VH) and bone marrow cell transient receptor potential vanilloid type 1 (TRPV1) and heat shock protein (HSP) 70 expression in a rat model of VH. Methods Mechanical colorectal distension was performed to induce VH in neonatal Sprague-Dawley rats. Eight-week-old VH rats were treated with moxibustion at acupuncture point BL25 or an ipsilateral non-acupuncture point. Abdominal withdrawal reflex (AWR) scoring and pain threshold pressure assessment were performed before and after moxibustion treatment for 7 consecutive days. The expression of TRPV1 and HSP70 in bone marrow cells was quantified by real-time quantitative PCR. Results The expression of TRPV1 and HSP70 in bone marrow cells was increased in rats with VH. Moxibustion at BL25 significantly decreased AWR scores and increased pain threshold pressure in rats with VH. Furthermore, moxibustion at BL25 significantly inhibited the VH-induced increase in the expression of TRPV1 and HSP70 in bone marrow cells. Conclusions The up-regulation of TRPV1 and HSP70 expression in bone marrow cells may be involved in visceral pain development and the analgesic effect of moxibustion on VH may be mediated through down-regulation of TRPV1 and HSP70 expression in bone marrow cells.

Gestational exposure to titanium dioxide nanoparticles impairs the placentation through dysregulation of vascularization, proliferation and apoptosis in mice

Background Titanium dioxide nanoparticles (TiO2 NPs) have recently found applications in a wide variety of consumer goods. TiO2 NPs exposure significantly increases fetal deformities and mortality. However, the potential toxicity of TiO2 NPs on the growth and development of placenta has been rarely studied during mice pregnancy. Purpose The objective of this study was to investigate the effects of maternal exposure of TiO2 NPs on the placentation. Methods Mice were administered TiO2 NPs by gavage at 0, 1 and 10 mg/kg/day from gestational day (GD) 1 to GD 13. Uteri and placentas from these mice were collected and counted the numbers of implanted and resorbed embryo and measured the placental weight on GD 13. Placental morphometry was observed by hematoxylin and eosin staining. The levels of Hand1, Esx1, Eomes, Hand2, Ascl2 and Fra1 mRNA were assessed by qRT-PCR. Uterine NK (uNK) cells were detected by using DBA lectin. Laminin immunohistochemical staining was to identify fetal vessels. Western blotting and transmission electron micrograph (TEM) were used to assess the apoptosis of placenta. Results No treatment-related difference was observed in the numbers of implanted and resorbed embryos and weight of placenta between the groups. However, 1 mg/kg/day TiO2 NPs treatment significantly reduced the ratio of placenta/body weight on GD 13. The proportion of spongiotrophoblast in the 10 mg/kg/day dose group became higher than that in the control group, yet that of labyrinth was significantly lower in 10 mg/kg/day mice. The expression levels of Hand1, Esx1, Eomes, Hand2, Ascl2 and Fra1 mRNA markedly decreased in TiO2 NP treated placentas. Furthermore, TiO2 NPs treatment impaired the formation of intricate networks of fetal vessels and reduced the number of uNK cells, and inhibited proliferation and induced apoptosis of placenta by nuclear pyknosis, the activation of caspase-3 and upregulation of Bax protein and downregulation of Bcl-2 protein on GD 13. Conclusion Gestational exposure to TiO2 NPs significantly impairs the growth and development of placenta in mice, with a mechanism that seems to be involved in the dysregulation of vascularization, proliferation and apoptosis. Therefore, our results suggested the need for great caution while handling of the nanomaterials by workers and specially pregnant consumers.

Estradiol Synthesis and Release in Cultured Female Rat Bone Marrow Stem Cells

Bone marrow stem cells (BMSCs) have the capacity to differentiate into mature cell types of multiple tissues. Thus, they represent an alternative source for organ-specific cell replacement therapy in degenerative diseases. In this study, we demonstrated that female rat BMSCs could differentiate into steroidogenic cells with the capacity for de novo synthesis of Estradiol-17β (E2) under high glucose culture conditions with or without retinoic acid (RA). The cultured BMSCs could express the mRNA and protein for P450arom, the enzyme responsible for estrogen biosynthesis. Moreover, radioimmunoassay revealed that BMSCs cultured in the present culture system produced and secreted significant amounts of testosterone, androstenedione, and E2. In addition, RA promoted E2 secretion but did not affect the levels of androgen. These results indicate that BMSCs can synthesize and release E2 and may contribute to autologous transplantation therapy for estrogen deficiency.

Down-Regulation of Neuropathy Target Esterase in Preeclampsia Placenta Inhibits Human Trophoblast Cell Invasion via Modulating MMP-9 Levels

Background/Aims: Neuropathy target esterase (NTE, also known as neurotoxic esterase) is proven to deacylate phosphatidylcholine (PC) to glycerophosphocholine as a phospholipase B. Recently; studies showed that artificial phosphatidylserine/PC microvesicles can induce preeclampsia (PE)-like changes in pregnant mice. However, it is unclear whether NTE plays a key role in the pathology of PE, a pregnancy-related disease, which was characterized by deficient trophoblast invasion and reduced trophoblast-mediated remodeling of spiral arteries. The aim of this study was to investigate the expression pattern of NTE in the placenta from women with PE and normal pregnancy, and the molecular mechanism of NTE involved in the development of PE. Methods: NTE expression levels in placentas from 20 pregnant women with PE and 20 healthy pregnant women were detected using quantitative PCR and immunohistochemistry staining. The effect of NTE on trophoblast migration and invasion and the underlying mechanisms were examined in HTR-8/SVneo cell lines by transfection method. Results: NTE mRNA and protein expression levels were significantly decreased in preeclamptic placentas than normal control. Over-expression of NTE in HTR-8/SVneo cells significantly promoted trophoblast cells migration and invasion and was associated with increased MMP-9 levels. Conversely, shRNA-mediated down-regulation of NTE markedly inhibited the cell migration and invasion. In addition, silencing NTE reduced the MMP-9 activity and phosphorylated Erk1/2 and AKT levels. Conclusions: Our results suggest that the decreased NTE may contribute to the development of PE through impairing trophoblast invasion by down-regulating MMP-9 via the Erk1/2 and AKT signaling pathway.