TET2-mediated DNA hydroxymethylation of TGFB1 is related to selective intrauterine growth restriction in monochorionic twin pregnancies.

INTRODUCTION: Selective intrauterine growth restriction (sIUGR), which specifically occurs in monochorionic (MC) twins, usually has a poor prognosis and the underlying mechanisms are not well understood. It is an ideal model for exploring epigenetic-modified mechanisms for fetal development in MCDA twins due to eliminating the interference of different heritable backgrounds and intrauterine environments among individuals. METHODS: The levels of ten-eleven translocation 2 (TET2) and its upstream and downstream targets miR-29b-3p and transforming growth factor beta 1 (TGFB1) were determined using RT‒qPCR, western blotting, and immunohistochemistry. Using TET2 overexpression and knockdown methods, we investigated the role of TET2 in trophoblast functions. The regulatory relationships among TET2, miR-29b-3p, and TGFB1 were explored by cell migration assay, invasion assay, apoptotic ratio assays, Western blot, hMeDIP-qPCR and dual-luciferase assay. RESULTS: A consistent upregulation of TET2 and TGFB1 was observed in the smaller placental shares compared to the larger placental shares in sIUGR. Gain-of-function studies of TET2 in trophoblasts showed decreased cell invasion and increased apoptosis, whereas loss-of-function studies of TET2 rescued this effect. Mechanistic studies revealed that miR-29b-3p and TGFB1 were the upstream factor and downstream target of TET2, respectively. Furthermore, miR-29b-3p/TET2/TGFB1-smad was identified as a unique axis that regulates trophoblast invasion, migration, and apoptosis in a DNA hydroxymethylation-dependent manner. DISCUSSION: We elucidated the functional roles of TET2 and DNA hydroxymethylation in trophoblasts and identified a novel DNA regulatory mechanism, providing a basis for further exploration of DNA epigenetic regulatory patterns in sIUGR.

Dynamical modelling of viral infection and cooperative immune protection in COVID-19 patients.

Once challenged by the SARS-CoV-2 virus, the human host immune system triggers a dynamic process against infection. We constructed a mathematical model to describe host innate and adaptive immune response to viral challenge. Based on the dynamic properties of viral load and immune response, we classified the resulting dynamics into four modes, reflecting increasing severity of COVID-19 disease. We found the numerical product of immune system's ability to clear the virus and to kill the infected cells, namely immune efficacy, to be predictive of disease severity. We also investigated vaccine-induced protection against SARS-CoV-2 infection. Results suggested that immune efficacy based on memory T cells and neutralizing antibody titers could be used to predict population vaccine protection rates. Finally, we analyzed infection dynamics of SARS-CoV-2 variants within the construct of our mathematical model. Overall, our results provide a systematic framework for understanding the dynamics of host response upon challenge by SARS-CoV-2 infection, and this framework can be used to predict vaccine protection and perform clinical diagnosis.

Case report: Fetal cervical immature teratoma and copy number variations.

Fetal cervical teratoma is a rare congenital neck tumor. Here, we report a case of a fetus with an anterior solid neck tumor that was confirmed to have an immature teratoma by histology. A duplication was found at chromosome 14q24.1-q24.3 of the fetus in chromosome microarray (CMA) and whole exome sequencing (WES), which was a copy number variation (CNV) and a probably new-onset. Ultrasound coupled with magnetic resonance imaging (MRI) can be considered to be a relatively reliable diagnostic tool, whereas ex-utero intrapartum therapy or resection of the tumor mass on placental support may improve the chances of the newborn's survival. Strangely, the same duplication occurred on her next fetus that was found with complex congenital heart malformations. CNV at chromosome 14q24.1-q24.3 needs to be paid more attention.

Rapid Quantification of Polyhydroxyalkanoates Accumulated in Living Cells Based on Green Fluorescence Protein-Labeled Phasins: The qPHA Method.

Polyhydroxyalkanoates (PHAs) are microbial polyesters that have the potential to replace nonbiodegradable petroplastics. A real-time in situ PHA quantification method has long been awaited to replace the traditional method, which is time- and labor-consuming. Quantification of PHA in living cells was finally developed from fluorescence intensities generated from the green fluorescence protein (GFP) fused with the Halomonas bluephagenesis phasin proteins. Phasins PhaP1 and PhaP2 were used to fuse with GFP, which reflected PHA accumulation with an R-square of over 0.9. Also, a standard correlation was established to calculate PHA contents based on the fluorescence and cell density recorded via a microplate reader with an R-square of over 0.95 when grown on various substrates. The PhaP2-GFP containing H. bluephagenesis was applied successfully to quantify PHA synthesis in a 7.5 L fermenter with high precision. Moreover, the method was found to be feasible in non-natural PHA producers such as Escherichia coli, demonstrating its broad applicability.

Distribution of Vaginal and Gut Microbiome in Advanced Maternal Age.

The distribution of the microbiome in women with advanced maternal age (AMA) is poorly understood. To gain insight into this, the vaginal and gut microbiota of 62 women were sampled and sequenced using the 16S rRNA technique. These women were divided into three groups, namely, the AMA (age ≥ 35 years, n = 13) group, the non-advanced maternal age (NMA) (age < 35 years, n = 38) group, and the control group (non-pregnant healthy women, age >35 years, n = 11). We found that the alpha diversity of vaginal microbiota in the AMA group significantly increased. However, the beta diversity significantly decreased in the AMA group compared with the control group. There was no significant difference in the diversity of gut microbiota among the three groups. The distributions of microbiota were significantly different among AMA, NMA, and control groups. In vaginal microbiota, the abundance of Lactobacillus was higher in the pregnant groups. Bifidobacterium was significantly enriched in the AMA group. In gut microbiota, Prevotella bivia was significantly enriched in the AMA group. Vaginal and gut microbiota in women with AMA were noticeably different from the NMA and non-pregnant women, and this phenomenon is probably related to the increased risk of complications in women with AMA.

Reversible thermal regulation for bifunctional dynamic control of gene expression in Escherichia coli.

Genetically programmed circuits allowing bifunctional dynamic regulation of enzyme expression have far-reaching significances for various bio-manufactural purposes. However, building a bio-switch with a post log-phase response and reversibility during scale-up bioprocesses is still a challenge in metabolic engineering due to the lack of robustness. Here, we report a robust thermosensitive bio-switch that enables stringent bidirectional control of gene expression over time and levels in living cells. Based on the bio-switch, we obtain tree ring-like colonies with spatially distributed patterns and transformer cells shifting among spherical-, rod- and fiber-shapes of the engineered Escherichia coli. Moreover, fed-batch fermentations of recombinant E. coli are conducted to obtain ordered assembly of tailor-made biopolymers polyhydroxyalkanoates including diblock- and random-copolymer, composed of 3-hydroxybutyrate and 4-hydroxybutyrate with controllable monomer molar fraction. This study demonstrates the possibility of well-organized, chemosynthesis-like block polymerization on a molecular scale by reprogrammed microbes, exemplifying the versatility of thermo-response control for various practical uses.

RIP1-dependent linear and nonlinear recruitments of caspase-8 and RIP3 respectively to necrosome specify distinct cell death outcomes.

There remains a significant gap in our quantitative understanding of crosstalk between apoptosis and necroptosis pathways. By employing the SWATH-MS technique, we quantified absolute amounts of up to thousands of proteins in dynamic assembling/de-assembling of TNF signaling complexes. Combining SWATH-MS-based network modeling and experimental validation, we found that when RIP1 level is below ~1000 molecules/cell (mpc), the cell solely undergoes TRADD-dependent apoptosis. When RIP1 is above ~1000 mpc, pro-caspase-8 and RIP3 are recruited to necrosome respectively with linear and nonlinear dependence on RIP1 amount, which well explains the co-occurrence of apoptosis and necroptosis and the paradoxical observations that RIP1 is required for necroptosis but its increase down-regulates necroptosis. Higher amount of RIP1 (>~46,000 mpc) suppresses apoptosis, leading to necroptosis alone. The relation between RIP1 level and occurrence of necroptosis or total cell death is biphasic. Our study provides a resource for encoding the complexity of TNF signaling and a quantitative picture how distinct dynamic interplay among proteins function as basis sets in signaling complexes, enabling RIP1 to play diverse roles in governing cell fate decisions.

[Effect of oral Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on vaginal Group B Streptococcus colonization and vaginal microbiome in late pregnancy].

OBJECTIVE: To explore the effects of intervention with oral probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on vaginal Group B Streptococcus (GBS) colonization, pregnancy outcome and vaginal microbiome in GBS-positive women in the third trimester of pregnancy. METHODS: This study were conducted among 155 women in the third trimester of pregnancy with positive results of GBS culture in the Outpatient Department of Zhujiang Hospital from March to November, 2019. After excluding 32 patients who received lactobacillus intervention for less than 2 weeks or underwent postpartum GBS retesting, the women were divided into oral probiotics intervention group (60 cases) and non-intervention group (63 cases). According to the results of GBS retesting, the 60 women in the intervention group were divided into GBS-negative group (18 cases) and persistent GBS-positive group (42 cases). At the end of the intervention, the rates of negative GBS culture result were calculated and the pregnancy outcomes were compared. From 5 women randomly selected from the intervention group, samples of vaginal secretions were collected before and after the intervention for amplicon sequencing and bioinformatics analysis. RESULTS: At the end of the intervention, the GBS-negative rate in the intervention group was 30% (18/60), as compared with 23% (3/13) in the non-intervention group. Probiotic intervention significantly reduced the incidence of premature rupture of membranes (P < 0.05) and reduced the use of antibiotics during pregnancy (P < 0.05). OTU analysis of the vaginal secretions suggested probiotic intervention decreased the total sequence number and GBS sequence number, increased the species composition, and significantly decreased GBS abundance (P < 0.05). Probiotics intervention also significantly decreased the species abundance of Enterococcus, Staphylococcus and Streptococcus in the vaginal flora (P < 0.05). CONCLUSIONS: Intervention with oral probiotics can reduce vaginal GBS colonization in late pregnancy and improve the pregnancy outcome. Lactobacillus is capable of reducing the abundance of GBS and other pathogenic bacteria to improve the microbiome of vaginal flora.