Origin and timing of de novo variants implicated in type 2 von Willebrand disease

Very few studies have shown the real origin and timing of de novo variants (DNV) implicated in von Willebrand disease (VWD). We investigated four families with type 2 VWD. First, we conducted linkage analysis using single nucleotide variant genotyping to recognize the possible provenance of DNV. Second, we performed amplification refractory mutation system‐quantitative polymerase chain reaction to confirm the real origin of variant (~0% mutant cells) or presence of a genetic mosaic variant (0%–50% mutant cells) in three embryonic germ layer‐derived tissues and sperm cells. Then, three possible timings of DNV were categorized based on the relative likelihood of occurrence according to the number of cell divisions during embryogenesis. Two each with type 2B VWD (proband 1 p.Arg1308Cys, proband 4 p.Arg1306Trp) and type 2A VWD (proband 2 p.Leu1276Arg, proband 3 p.Ser1506Leu) were identified. Variant origins were identified for families 1, 2 and 3 and confirmed to originate from the mother, father and father, respectively. However, the father of family 4 was confirmed to have isolated germline mosaicism with 2.2% mutant sperm cells. Further investigation confirmed the paternal grandfather to be the origin of variant. Thus, we proposed that DNV originating from the two fathers most likely occurred at the single sperm cell, the one originating from the mother occurred at the zygote during the first few cellular divisions; alternatively, in family 4, the DNV most likely occurred at the early postzygotic development in the father. Our findings are essential for understanding genetic pathogenesis and providing accurate genetic counselling.     

Resveratrol induces AMPK and mTOR signaling inhibition-mediated autophagy and apoptosis in multiple myeloma cells

Resveratrol,a natural compound extracted from the skins of grapes,berries,or other fruits,has been shown to have anti-tumor effects against multiple myeloma(MM)...     

Modification of alternative splicing in bovine somatic cell nuclear transfer embryos using engineered CRISPR-Cas13d

Animal cloning can be achieved by somatic cell nuclear transfer(SCNT), but the resulting live birth rate is relatively low. We previously improved the efficiency of bovine SCNT by exogenous melatonin treatment or by overexpression of lysine-specific demethylase 4D(KDM4D) and 4E(KDM4E). In this study, we revealed abundant alternative splicing(AS) transitions during fertilization and embryonic genome activation, and demonstrated abnormal AS in bovine SCNT embryos compared with in vitro fertilized ...     

Studying bona fide SARS-CoV-2 biology in a BSL-2 biosafety environment using a split-virus-genome system

<正>Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARSCoV-2) was identified as the pathogen causing the coronavirus disease(COVID-19), which sometimes resulted in fatal pneumonia(Hu et al., 2021). SARS-CoV-2 is a biosafety level 3(BSL-3) pathogen, and the requirement for high containment conditions is a bottleneck for basic research on viral biology.     

大棚黄瓜霜霉病气候生态防治方法研究再报——高温控制与病情和产量关系及其防治指标

本文采用田间温度控制试验资料,用数理统计的方法分析高温控制范围、控制时间和控制频率与大棚黄瓜霜霉病的发生期、流行期、发生程度以及产量的关系,并建立了统计相关模式,确定了高温控制生态防治方法的技术指标。最高温度、高温控制时间和控制频率这3个主要指标与病情和黄瓜产量的关系非常密切,最高气温每升高1℃,发病期和流行期将推迟3—5天,病叶率降低13—15％,黄瓜产量可增长10％左右。在一定范围内,控制时间越长,频率越高,则发病期和流行期越晚,病情越轻,产量越高。研究证明,高温控制方法是一个有效的生态防治方法,具有明确的气候生态学依据。     

MiR‐616‐3p modulates cell proliferation and migration through targeting tissue factor pathway inhibitor 2 in preeclampsia

Objectives

Despite improvements in diagnosis and treatment, preeclampsia (PE) continues to pose a significant risk of maternal and foetal morbidity and mortality if not addressed promptly. An increasing number of studies have suggested that tissue factor pathway inhibitor 2 (TFPI2) acts as a suppressor gene, possibly inhibiting multiple serine proteases affecting cell proliferation and migration. It plays an essential role in the occurrence and development of PE, but the pathogenesis remains unclear.

Materials and methods

In our research, we performed western blotting, immunohistochemistry and qPCR assays to investigate TFPI2 and miR‐616‐3p expression in preeclamptic placental tissues. Cell assays were performed in HTR‐8/SVneo and JEG3 cell lines. Cell proliferation and migration events were investigated by MTT, EdU and transwell assays. In conjunction with bioinformatics analysis, luciferase reporter assays were performed to elucidate the mechanism by which miR‐616‐3p binds to TFPI2 mRNA.

Results

We established that TFPI2 protein levels were significantly upregulated in PE placental tissues. In addition, we found that miR‐616‐3p binds specifically to the 3′‐UTR region of TFPI2 mRNA. Furthermore, miR‐616‐3p knockdown or TFPI2 overexpression substantially impaired cell growth and migration, whereas miR‐616‐3p upregulation or TFPI2 knockdown stimulated cell proliferation and migration. This miR‐616‐3p / TFPI2 axis was also found to affect the epithelial‐mesenchymal transition process in PE.

Conclusions

Our results demonstrated that TFPI2 plays a vital role in the progression of PE and might provide a prospective therapeutic strategy to mitigate the severity of the disorder.

     

C4-dicarboxylates sensing mechanism revealed by the crystal structures of DctB sensor domain

C₄-dicarboxylates are the major carbon and energy sources during the symbiotic growth of rhizobia. Responses to C₄-dicarboxylates depend on typical two-component systems (TCS) consisting of a transmembrane sensor histidine kinase and a cytoplasmic response regulator. The DctB-DctD system is the first identified TCS for C₄-dicarboxylates sensing. Direct ligand binding to the sensor domain of DctB is believed to be the first step of the sensing events. In this report, the water-soluble periplasmic sensor domain of Sinorhizobium meliloti DctB (DctBp) was studied, and three crystal structures were solved: the apo protein, a complex with C₄ succinate, and a complex with C₃ malonate. Different from the two structurally known CitA family of carboxylate sensor proteins CitA and DcuS, the structure of DctBp consists of two tandem Per-Arnt-Sim (PAS) domains and one N-terminal helical region. Only the membrane-distal PAS domain was found to bind the ligands, whereas the proximal PAS domain was empty. Comparison of DctB, CitA, and DcuS suggests a detailed stereochemistry of C₄-dicarboxylates ligand perception. The structures of the different ligand binding states of DctBp also revealed a series of conformational changes initiated upon ligand binding and propagated to the N-terminal domain responsible for dimerization, providing insights into understanding the detailed mechanism of the signal transduction of TCS histidine kinases.