Metagenomic Next-generation Sequencing May be a Tool for Timely Diagnosis of Seronegative and Primary Toxoplasma Infection After Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report and Literature Review.

We report a case of Toxoplasma gondii ( T. gondii ) antibody seronegativity in a 14-year-old boy with a primary infection of T. gondii after allogeneic hematopoietic stem cell transplantation for acute T-cell lymphoblastic leukemia who was rapidly diagnosed through metagenomic next-generation sequencing of peripheral blood as well as clinical manifestations. He was successfully cured with timely administration of trimethoprim-sulfamethoxazole due to early diagnosis.

Astragaloside-IV induces the differentiation of bone marrow mesenchymal stem cells into osteoblasts through NMUR2-mediated Wnt/ß-catenin pathway.

Aim: Given that astragaloside-IV (As-IV) has the ability to promote osteogenic differentiation, its mechanism is worthy of exploration. Methods: The effect of As-IV on rat tibial defects was examined by histopathological staining and MiR-CT scan. The alkaline phosphatase (ALP) content, osteogenic differentiation-related gene expressions, and mineralized nodule formation in bone marrow mesenchymal stem cells (BMSCs) were detected. Results: As-IV repaired tibial defects of rats. As-IV or neuromedin receptor 2 (NMUR2) overexpression elevated ALP content, mineralized nodules, osteogenic differentiation-related genes, ß-catenin and NMUR2 levels, the effects of which were reversed by NMUR2 silencing or Wnt/ß-catenin pathway inhibitors. Conclusion: As-IV regulates the Wnt/ß-catenin pathway through NMUR2 to promote the repair of tibial defects in rats and the differentiation of BMSCs into osteoblasts.

Case report: Germline RECQL mutation potentially involved in hereditary predisposition to acute leukemia.

The pathogenesis of acute leukemia is still complex and vague. Most types of acute leukemia are related to somatic gene mutations, and familial incidence is rare. Here we report a case of familial leukemia. The proband presented to our hospital with vaginal bleeding and disseminated intravascular coagulation at the age of 42 and was diagnosed with acute promyelocytic leukemia with typical PML-RARα fusion gene caused by t(15;17)(q24;q21) translocation. By taking the history, we found that the patient's second daughter had been diagnosed with B-cell acute leukemia with ETV6-RUNX1 fusion gene at age 6. Then we performed whole exome sequencing in peripheral blood mononuclear cells from these two patients at remission status and identified 8 shared germline gene mutations. Using functional annotation and Sanger sequencing validation, we finally focused on a single nucleotide variant in RecQ like helicase (RECQL), rs146924988, which was negative in the proband's healthy eldest daughter. This gene variant potentially led to a relative lack of RECQL protein, disordered DNA repair and chromatin rearrangement, which may mediate the occurrence of fusion genes, as driving factors for leukemia. This study identified a novel possible leukemia-related germline gene variant and provided a new understanding for the screening and pathogenesis of hereditary predisposition syndromes.

Astragaloside IV Improves Tibial Defect in Rats and Promotes Proliferation and Osteogenic Differentiation of hBMSCs through MiR-124-3p.1/STAT3 Axis.

Astragaloside IV (AST-IV) facilitates the proliferation and migration of osteoblast-like cells. We sought to explore the effect and potential mechanism of AST-IV on regeneration of tibial defects. To reveal the effect of AST-IV on regeneration of tibial defects in rat, HE staining and microcomputed tomography (µCT) were performed on tibial bone. The binding relationship between miR-124-3p.1 and STAT3 was analyzed by TargetScan V7.2 and a dual-luciferase reporter assay. Human bone marrow mesenchymal stromal/stem cells (hBMSCs) were identified by morphological observation and flow-cytometric analysis. To reveal the effect and mechanism of AST-IV on phenotypes of hBMSCs, hBMSCs were treated with AST-IV, miR-124-3p.1 mimic, and pcDNA-STAT3, and cell viability, cell cycle, ALP activity, and calcium deposition of hBMSCs in vitro were determined by MTT, flow-cytometric analysis, ELISA, and Alizarin red staining, respectively. The expressions of osteoblast marker molecules (RUNX2, OCN, Smad4), miR-124-3p.1, and STAT3 were indicated by RT-qPCR and Western blot. AST-IV decreased miR-124-3p.1 expression, increased STAT3 expression in tibial bone defects, and promoted regeneration of tibial bone defects in a concentration-dependent manner. The hBMSCs appeared spindle-shaped and were positive for CD105, but negative for CD34. MiR-124-3p.1 negatively regulated STAT3 expression in hBMSCs under osteogenic conditions. AST-IV promoted viability, cell cycle, ALP activity, and osteogenic differentiation of hBMSCs along with increased expressions of osteoblast marker molecules, which was partially reversed by miR-124-3p.1 overexpression. However, the effect of miR-124-3p.1 overexpression on hBMSCs was also partially reversed by STAT3 overexpression. AST-IV improves tibial defects in rats and promotes proliferation and osteogenic differentiation of hBMSCs through the miR-124-3p.1/STAT3 axis.

An Equation Based on Fuzzy Mathematics to Assess the Timing of Haemodialysis Initiation.

In order to develop an equation that integrates multiple clinical factors including signs and symptoms associated with uraemia to assess the initiation of dialysis, we conducted a retrospective cohort study including 25 haemodialysis centres in Mainland China. Patients with ESRD (n = 1281) who commenced haemodialysis from 2008 to 2011 were enrolled in the development cohort, whereas 504 patients who began haemodialysis between 2012 and 2013 were enrolled in the validation cohort comprised. An artificial neural network model was used to select variables, and a fuzzy neural network model was then constructed using factors affecting haemodialysis initiation as input variables and 3-year survival as the output variable. A logistic model was set up using the same variables. The equation's performance was compared with that of the logistic model and conventional eGFR-based assessment. The area under the bootstrap-corrected receiver-operating characteristic curve of the equation was 0.70, and that of two conventional eGFR-based assessments were 0.57 and 0.54. In conclusion, the new equation based on Fuzzy mathematics, covering laboratory and clinical variables, is more suitable for assessing the timing of dialysis initiation in a Chinese ESRD population than eGFR, and may be a helpful tool to quantitatively evaluate the initiation of haemodialysis.

MicroRNA-153 suppresses the osteogenic differentiation of human mesenchymal stem cells by targeting bone morphogenetic protein receptor type II.

Elucidation of the molecular mechanisms governing the osteogenic differentiation of human mesenchymal stem cells (hMSCs) is of great importance for improving the treatment of bone-related diseases. MicroRNAs (miRNAs or miRs), a class of small non-coding RNAs, are critical in a number of biological processes, including the proliferation, differentiation and survival of cells and organisms. Emerging evidence indicates that miRNAs are essential in regulating osteoblastogenesis and bone formation. However, the role of miRNAs in osteoblast mechanotransduction remains to be defined. The present study aimed to examine the role of miR-153 in the osteogenesis of hMSCs and to investigate the impact of miR-153 on bone morphogenetic protein receptor type II (BMPR2) expression. The overexpression of miR-153 inhibited the osteogenic differentiation of hMSCs, whereas downregulation of miR-153 enhanced the process. Furthermore, bioinformatic analysis predicted that miR-153 is a potential regulator of BMPR2. The direct binding of miR-153 to the BMPR2 3'-untranslated region (3'-UTR) was demonstrated by a luciferase reporter assay using a construct containing the BMPR2 3'-UTR. In addition, knockdown of BMPR2 by RNA interference inhibited the osteogenic differentiation of hMSCs, with a similar effect to the upregulation of miR-153. In conclusion, the results suggest that miR-153 is a mechano-sensitive miRNA that regulates osteoblast differentiation by directly targeting BMPR2, and that therapeutic inhibition of miR-153 may be an efficient anabolic strategy for skeletal disorders caused by pathological mechanical loading.