Preface

Prefac

Green extraction of phenolic compounds from foxtail millet bran by ultrasonic-assisted deep eutectic solvent extraction: Optimization, comparison and bioactivities

An ultrasonic-assisted extraction (UAE) protocol using deep eutectic solvent (DES) was employed to extract phenolic compounds from foxtail millet bran (FMB). DES composed with betaine and glycerol in a 1:2 M ratio was selected basing on the total phenolic content (TPC) extraction yield, with the optimal extraction technology investigated using response surface methodology (RSM) with Box-Behnken design (BBD). The optimized process obtained was as follows: DESs with water content of 29 mL/100 mL, ultrasonic power at 247 W, extraction temperature of 61 °C, and extraction time of 31 min. The TPC of the extract was 7.80 ± 0.09 mg ferulic acid equivalent (FAE)/g under the optimum extraction conditions, with the result corresponding well with the model prediction. DES-based UAE produced higher total phenolics, total flavonoids, in vitro antioxidant activity and acetylcholinesterase inhibitory activity than the conventional solvent extraction. The phenolic extract from FMB with DES-based UAE was mainly composed of fifteen phenolic compounds, with p-coumaric acid, apigenin-C-dihexoside, and N′, N″-di-p-coumaroylspermidine being the predominant phenolic compounds. Additionally, 1-O-p-coumaroylglycerol was detected for the first time in FMB. The microstructure differences of the FMB samples following extraction were confirmed using scanning electron microscopy (SEM)

SATB1 down-regulation induced by oxidative stress participates in trophoblast invasion by regulating β-catenin.

Preeclampsia (PE) is characterized by abnormal placentation in the early stages of pregnancy. Adequate migration and invasion of trophoblasts into the uterine wall and spiral arteries to form a functional maternal-fetal interface are pivotal for normal placentation, but the exact mechanism remains unclear. Growing evidence has revealed that special AT-rich sequence-binding protein 1 (SATB1) is a tumor promoter that participates in cancer cell migration and invasion. However, the expression and function of SATB1 in trophoblasts is unknown. Here, we characterize the stimulatory effect of SATB1 on the migration and invasion of trophoblasts and identify the regulatory events and downstream signaling components. Down-regulated SATB1 was detected in PE placentae and villous explants cultured under hypoxia/re-oxygenation (H/R) conditions. H/R-treated trophoblasts with lower SATB1 levels exhibited weaker invasive and growth capacities, whereas up-regulation of the SATB1 level with recombinant SATB1 restored these impairments. This restoration was especially apparent with the sumoylation-deficientSATB1 variant, which contained a mutated site that blocked sumoylation. Moreover, the elevated concentration of SATB1 also increased the expression of β-catenin, which is involved in human placental trophoblast invasion and differentiation and is down-regulated in PE. However, a specific activator, namely, lithium chloride (LiCl), increased β-catenin expression but had no evident influence on SATB1expression. Furthermore, up-regulated SATB1 failed to restore trophoblast function when Wnt/β-catenin was suppressed by Dickkopf1(DKK1).Together, these data show thatSATB1expression in the human placenta is affected by oxidative stress and might regulate the migration and invasion of trophoblasts via β-catenin signaling

Hypoxia-induced Downregulation of SRC-3 Suppresses Trophoblastic Invasion and Migration Through Inhibition of the AKT/mTOR Pathway: Implications for the Pathogenesis of Preeclampsia.

Preeclampsia (PE) is characterized by poor placentation, consequent on aberrant extravillous trophoblast (EVT) cell function during placental development. The SRC family of proteins is important during pregnancy, especially SRC-3, which regulates placental morphogenesis and embryo survival. Although SRC-3 expression in mouse trophoblast giant cells has been documented, its role in the functional regulation of extravillous trophoblasts and the development of PE remains unknown. This study found that SRC-3 expression was significantly lower in placentas from PE pregnancies as compared to uncomplicated pregnancies. Additionally, both CoCl2-mimicked hypoxia and suppression of endogenous SRC-3 expression by lentivirus short hairpin RNA attenuated the migration and invasion abilities of HTR-8/SVneo cells. Moreover, we demonstrated that SRC-3 physically interacts with AKT to regulate the migration and invasion of HTR-8 cells, via the AKT/mTOR pathway. We also found that the inhibition of HTR-8 cell migration and invasion by CoCl2-mimicked hypoxia was through the SRC-3/AKT/mTOR axis. Our findings indicate that, in early gestation, accumulation of HIF-1α inhibits the expression of SRC-3, which impairs extravillous trophoblastic invasion and migration by directly interacting with AKT. This potentially leads to insufficient uterine spiral artery remodeling and placental hypoperfusion, and thus the development of PE

The Regulation of Trophoblastic p53 Homeostasis by the p38-Wip1 Feedback Loop is Disturbed in Placentas from Pregnancies Complicated by Preeclampsia.

BACKGROUND/AIMS: Excessive apoptosis of trophoblasts, induced by sustained hypoxia, leads to abnormal placentation and is strongly linked to pregnancy complications such as preeclampsia (PE). Wild-type p53-induced phosphatase (Wip1) positively regulates cellular survival in tumor cells through the p38 and p53 pathways, but its expression pattern and effects in trophoblasts have yet to be reported. This study clarified the effect of Wip1 on the regulatory mechanism of p53-dependent apoptosis in trophoblasts, and thus increases understanding of the etiology of PE. METHODS: In normal and PE placentas, Wip1 mRNA and protein levels were determined by RT-qPCR and Western blotting respectively, while localization of Wip1 in placental tissues and in HTR8/SVneo cells was determined by immunohistochemistry and immunofluorescence. Two in vitro trophoblastic PE models were established by subjecting HTR8/SVneo cells to either hypoxia intervention in incubator (HII) or simulated ischemic buffer (SIB). Wip1 was suppressed in the aforementioned PE models by specific inhibitor or shRNA, and apoptosis was then assessed by flow cytometry, while further validation was done by measurement of cleaved-caspase 9 expression by Western blotting. The p38 inhibitor SB202190, Mdm2 inhibitor NVP-CGM097, and proteasome inhibitor MG-132 were administered in PE models, either in combination or alone, to determine the regulatory order of the component signal molecules of the feedback loop. The impact of Wip1 on p53-Mdm2 interaction was examined by coimmunoprecipitation. Lastly, the upregulation of the p38-Wip1 loop was confirmed in human placentas from pregnancies complicated by PE, using Western blotting. RESULTS: Wip1 expression was significantly elevated in human PE placentas and in vitro trophoblastic PE models; this is opposite to the pattern observed in tumor cells. Inhibition of Wip1 rescued hypoxia-induced p38 activation, cleavage of caspase 9 and apoptosis but significantly compromised p53-Mdm2 binding, while p-p53Ser15 was increased. Inhibition of Mdm2 degradation resulted in p53 destabilization and p38-Wip1 loop down-regulation, while degradation of the p53-Mdm2 complex resulted in p53 accumulation and p38-Wip1 loop hyperactivation. However, the p53-Mdm2 interaction was found to be more important in the regulation of the p38-Wip1 loop than Mdm2 stability. CONCLUSION: Trophoblastic p53 homeostasis is maintained by the p38-Wip1 feedback regulatory loop in response to hypoxic stress, which is dysregulated in the placentas of pregnancies complicated by PE, and thereby leads to excessive apoptosis