Human placenta-derived mesenchymal stem cells induce trophoblast invasion via dynamic effects on mitochondrial function.

The trophoblast is a critical cell for placental development and embryo implantation in the placenta. We previously reported that placenta-derived mesenchymal stem cells (PD-MSCs) increase trophoblast invasion through several signaling pathways. However, the paracrine effects of PD-MSCs on mitochondrial function in trophoblasts are still unclear. Therefore, the objective of the study was to analyze the mitochondrial function of trophoblasts in response to cocultivation with PD-MSCs. The results showed that PD-MSCs regulate the balance between cell survival and death and protect damaged mitochondria in trophoblasts from oxidative stress. Moreover, PD-MSCs upregulate factors involved in mitochondrial autophagy in trophoblast cells. Finally, PD-MSCs improve trophoblast invasion. Taken together, the data indicate that PD-MSCs can regulate trophoblast invasion through dynamic effects on mitochondrial energy metabolism. These results support the fundamental role of mitochondrial energy mechanism in trophoblast invasion and suggest a new therapeutic strategy for infertility.

Mitochondrial Dynamics in Placenta-Derived Mesenchymal Stem Cells Regulate the Invasion Activity of Trophoblast.

Mitochondrial dynamics are involved in many cellular events, including the proliferation, differentiation, and invasion/migration of normal as well as cancerous cells. Human placenta-derived mesenchymal stem cells (PD-MSCs) were known to regulate the invasion activity of trophoblasts. However, the effects of PD-MSCs on mitochondrial function in trophoblasts are still insufficiently understood. Therefore, the objectives of this study are to analyze the factors related to mitochondrial function and investigate the correlation between trophoblast invasion and mitophagy via PD-MSC cocultivation. We assess invasion ability and mitochondrial function in invasive trophoblasts according to PD-MSC cocultivation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and extracellular flux (XF) assay. Under PD-MSCs co-cultivation, invasion activity of a trophoblast is increased via activation of the Rho signaling pathway as well as Matrix metalloproteinases (MMPs). Additionally, the expression of mitochondrial function (e.g., reactive oxygen species (ROS), calcium, and adenosine triphosphate (ATP) synthesis) in trophoblasts are increased via PD-MSCs co-cultivation. Finally, PD-MSCs regulate mitochondrial autophagy factors in invasive trophoblasts via regulating the balance between PTEN-induced putative kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PARKIN) expression. Taken together, these results demonstrate that PD-MSCs enhance the invasion ability of trophoblasts via altering mitochondrial dynamics. These results support the fundamental mechanism of trophoblast invasion via mitochondrial function and provide a new stem cell therapy for infertility.

A unique biochemical reaction pathway towards trehalulose synthesis by an amylosucrase isolated from Deinococcus deserti.

The aim of this study was to establish an efficient bioprocess for the synthesis of trehalulose as a novel sweetener. This disaccharide has 70% of the sweetness of sucrose and bioactive properties such as anti-cariogenicity and anti-oxidizing activity. In this study, amylosucrase from the Deinococcus deserti (DdAS) gene was expressed and purified. When DdAS was reacted with 2 M sucrose at 35 °C for 120 h, the yield ratio of trehalulose to turanose was approximately 2:1. The trehalulose yield increased when extrinsic fructose was added. Under optimum conditions for trehalulose synthesis, the yield reached 36% (246 g/L, sucrose basis) starting with 2 M sucrose + 0.75 M fructose and showed the highest trehalulose productivity (1.94 g/L/h). As a result, a novel amylosucrase that synthesized trehalulose as the major product was developed, in contrast to other studied amylosucrase-type enzymes. DdAS could be utilized industrially in a bioprocess for producing trehalulose as a functional sucrose alternative.

Cryoprotective effect of turanose on lyophilized Lactobacillus paracasei subsp. paracasei, L. casei 431.

The lyophilization process is the most convenient and successful method to preserve probiotics, although microorganisms are exposed to conditions of extremely low freezing temperatures as well as dehydration. In this study, we evaluated the cryoprotective effect of turanose on Lactobacillus paracasei subsp. paracasei, L. casei 431 (L. casei 431) as a method to increase survival rate by improving cell viability. The results indicated that the viability of L. casei 431 was 9.6% without the cryoprotective agent, whereas bacterial cell viability was increased to 67.1% with the addition of 12% turanose. When turanose-treated freeze-dried cells were stored at 4 °C for 30 days, the survival rate decreased from 67.1 to 53.4%. Furthermore, cell viability significantly decreased by 50% after 30 days when stored at 25 °C with the same amount of turanose. Overall, turanose may be used as an effective cryoprotectant to preserve probiotics against the freeze-drying process and for extended storage at 4 °C.

Site-Directed Mutagenic Engineering of a Bifidobacterium Amylosucrase toward Greater Efficiency of Turanose Synthesis.

The aim of this study was to establish one of the most efficient biocatalytic processes for turanose production by applying a robust Bifidobacterium thermophilum (BtAS) mutant developed through site-directed mutagenesis. A gene encoding the amylosucrase of B. thermophilum (BtAS) was cloned and used as a mutagenesis template. Among the BtAS variants generated by the site-directed point mutation, four different single-point mutants (P200R, V202I, Y265F, and Y414F) were selected to create double-point mutants, among which BtASY414F/P200R displayed the greatest turanose productivity without losing the thermostability of native BtAS. The turanose yield of BtASY414F/P200R reached 89.3% at 50 °C after 6 h with 1.0 M sucrose + 1.0 M fructose. BtASY414F/P200R produced significantly more turanose than BtAS-wild type (WT) by 2 times and completed the reaction faster by another 2 times. Thus, turanose productivity (82.0 g/(L h)) by BtASY414F/P200R was highly improved from 28.1 g/(L h) of BtAS-WT with 2.0 M sucrose + 0.75 M fructose.

Differentiated structure of synthetic glycogen-like particle by the combined action of glycogen branching enzymes and amylosucrase.

Glycogen-like particles (GLPs) were built up from sucrose by applying de novo one-pot enzymatic process of amylosucrase (ASase; 6 U·mL-1) and glycogen branching enzymes (GBEs; 0.001 and 0.005 U·mL-1). Due to different chain-length transferring patterns of GBEs, structurally differentiated GLPs were synthesized. Yields of GLPs synthesized at pH 7.0 and 30 °C were improved by increasing the GBE/ASase ratio. Branching degrees of GLPs obviously was increased along with the ratio of GBEs, of which result was directly supported by shortened branch-chain length with greater GBE activity. Long branch chains seemed to play as efficient acceptor molecules to bind newly transferred branch chains especially at lower ratio of GBE/ASase, resulting in greater molecular weight and size of GLP with higher proportion of them. Molecular weight, size, and density of GLPs were ranged from 7.37 × 105 to 1.94 × 108 g·mol-1, from 23.70 to 52.65 nm, and from 7.99 to 374.32 g·mol-1·nm-3, respectively. By increasing GBE/ASase ratio, more compact GLP architecture was fabricated due to increased weight and reduced size with exception of a unique GBE. GLPs were efficiently synthesized by two different glycosyltransferases, and their chemical structures were controllable by source and ratio of GBEs due to their different branch-chain transferring specificity.