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

New Fructokinase, OsFRK3, Regulates Starch Accumulation and Grain Filling in Rice

Plant fructokinase (FRK) guarantees the growth and development of higher plants by participating in carbohydrate metabolism. In this study, a new fructokinase, OsFRK3, was identified using bioinformatics analysis, enzyme assay, bacterial growth assay, and yeast complementation test. Then, we created OsFRK3 knockout transgenic lines (osfrk3-1 and osfrk3-2) by the CRISPR/Cas9 technology. We found that the 1000-grain weight decreased notably (approximately −3.6% and −6.1%, respectively) in osfrk3-1 and osfrk3-2. Evidently decreased grain width, grain thickness, and endosperm filling rate were detected in the osfrk3 mutants (osfrk3-1 and osfrk3-2) compared with those of the WT. In addition, the content of seed total starch was significantly decreased by 3.42 and 4.80% in osfrk3 lines, compared with that in the WT. The level of maltose was significantly reduced in the mutants, while that of sucrose and fructose was obviously increased in the mutants. The transcript levels of OsGBSS1, OsBEIIb, OsPFP1β, and OsAGPL1 were significantly decreased in the osfrk3 mutants. These results suggest that OsFRK3 may positively regulate the accumulation of starch through influencing the sugar metabolism