Raman spectroscopy is an analytical method with a broad range of applications across multiple scientific fields. We report on a possibility to differentiate between two important Gram-positive species commonly found in clinical material - and - using this rapid noninvasive technique. : For this, we tested 87 strains, 41 of and 46 of , directly from colonies grown on a Mueller-Hinton agar plate using Raman spectroscopy. The method paves a way for separation of these two species even on high number of samples and therefore, it can be potentially used in clinical diagnostics.
An inherent difficulty in using DNA microarray technology on the early mouse embryo is its relatively small size. In this study, we investigated whether use of ES cell differentiation culture, which has no theoretical limit in the number of cells that can be generated, can improve this situation. Seven distinct ES-cell-derived populations were analyzed by DNA microarray and examined for genes whose distribution patterns are similar to those of PDGFRα, a gene implicated in differentiation of mesoderm/mesenchymal lineages. Using software developed in our laboratory, we formed a group of 30 genes which showed the highest similarity to PDGFRα, 18 of these genes were shown to be involved in development of either mesodermal, mesenchymal or neural crest cells. This list also contains several genes whose role in embryogenesis has not yet been fully identified. One such molecule is mARID3b. The mARID3b expression is found in the paraxial mesoderm and cranial mesenchyme. mARID3b-null mouse showed early embryonic lethality, and most phenotypes of this mutant appear to develop from a failure to generate a sufficient number of cranial mesenchymal cells. These results demonstrate the potential use of ES cell differentiation culture in identifying novel genes playing an indispensable role in embryogenesis.
Memory CD8 T cells are a critical component of protective immunity, and inducing effective memory T-cell responses is a major goal of vaccines against chronic infections and tumours. Considerable effort has gone into designing vaccine regimens that will increase the magnitude of the memory response, but there has been minimal emphasis on developing strategies to improve the functional qualities of memory T cells. Here we show that mTOR (mammalian target of rapamycin, also known as FRAP1) is a major regulator of memory CD8 T-cell differentiation, and in contrast to what we expected, the immunosuppressive drug rapamycin has immunostimulatory effects on the generation of memory CD8 T cells. Treatment of mice with rapamycin following acute lymphocytic choriomeningitis virus infection enhanced not only the quantity but also the quality of virus-specific CD8 T cells. Similar effects were seen after immunization of mice with a vaccine based on non-replicating virus-like particles. In addition, rapamycin treatment also enhanced memory T-cell responses in non-human primates following vaccination with modified vaccinia virus Ankara. Rapamycin was effective during both the expansion and contraction phases of the T-cell response; during the expansion phase it increased the number of memory precursors, and during the contraction phase (effector to memory transition) it accelerated the memory T-cell differentiation program. Experiments using RNA interference to inhibit expression of mTOR, raptor (also known as 4932417H02Rik) or FKBP12 (also known as FKBP1A) in antigen-specific CD8 T cells showed that mTOR acts intrinsically through the mTORC1 (mTOR complex 1) pathway to regulate memory T-cell differentiation. Thus these studies identify a molecular pathway regulating memory formation and provide an effective strategy for improving the functional qualities of vaccine- or infection-induced memory T cells.
A multifunctional nanoscale polymersome is developed for directing neuronal differentiation of neural stem cells (NSCs) by Jun Shen and co‐workers in article number 1706769 . Superparamagnetic iron oxide nanoparticles and small interfering RNA can be co‐delivered into NSCs, allowing for directing neuronal differentiation through silencing the NgR gene and non‐invasive migration monitoring. The study shows the great potential of nanomedicine in stroke treatment using stem cell transplantation.
Background/Aims: The aim of this study was to investigate the influence of Cx43-and Smad-mediated TGF-beta/BMP signaling pathway on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into cartilage and inhibition of ossification. Methods: BMSCs of Wistar rats were cultured and assigned into 5 groups for transfection with adenoviruses. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed to detect mRNA and protein expressions of target genes. The condition of cartilage and ossification were measured by a series of staining methods. Subcutaneous injection of mesenchymal stem cells (MSCs) into nude rats was performed. Results: After transfection, compared to the AdGFP group, the corresponding target mRNAs were overexpressed in the AdBMP2, AdSmad1, AdCx43 + AdSmad1 and AdCx43 + AdSmad1 + AdBMP2 groups, and overexpression of BMP2 at the mRNA and protein expression was observed in the AdSmad1 and AdCx43 + AdSmad1 groups. The mRNA expressions of aggrecan (ACAN) and collagen type II alpha 1 (Col2a1), the glycosaminoglycan content of the extracellular matrix and the expression of type II collagen, Col2a1, osteopontin (OPN) and osteocalcin (OC) were higher in the AdBMP2, AdSmad1, AdCx43 + AdSmad1 and AdCx43 + AdSmad1 + AdBMP2 groups than in the AdGFP group; alkaline phosphatase (ALP) activity and mRNA and protein expressions of Runx2 were also higher in these groups than in the AdGFP group. Heterotopic osteogenesis tests demonstrated evident cartilage differentiation ability in the AdCx43 + AdSmad1 + AdBMP2 groups. In comparison,the AdCx43 + AdSmad1 and AdSmad1 groups exhibited weaker cartilage differentiation abilities. Conclusion: Cx43 and Smad1 promote BMP-induced cartilage differentiation of BMSCs and inhibit osteoblast differentiation, which provide a new strategy for cartilage tissue engineering using exogenous Cx43 and Smad1. (C) 2017 The Author(s) Published by S. Karger AG, Basel
Oligodendrocyte development is regulated by the interaction of repressors and activators in a complex transcriptional network. We found that two histone-modifying enzymes, HDAC1 and HDAC2, were required for oligodendrocyte formation. Genetic deletion of both Hdac1 and Hdac2 in oligodendrocyte lineage cells resulted in stabilization and nuclear translocation of beta-catenin, which negatively regulates oligodendrocyte development by repressing Olig2 expression. We further identified the oligodendrocyte-restricted transcription factor TCF7L2/TCF4 as a bipartite co-effector of beta-catenin for regulating oligodendrocyte differentiation. Targeted disruption of Tcf7l2 in mice led to severe defects in oligodendrocyte maturation, whereas expression of its dominant-repressive form promoted precocious oligodendrocyte specification in developing chick neural tube. Transcriptional co-repressors HDAC1 and HDAC2 compete with beta-catenin for TCF7L2 interaction to regulate downstream genes involved in oligodendrocyte differentiation. Thus, crosstalk between HDAC1/2 and the canonical Wnt signaling pathway mediated by TCF7L2 serves as a regulatory mechanism for oligodendrocyte differentiation.
The transcription factors that regulate differentiation into the monocyte subset in bone marrow have not yet been identified. Here we found that the orphan nuclear receptor NR4A1 controlled the differentiation of Ly6C(-) monocytes. Ly6C(-) monocytes, which function in a surveillance role in circulation, were absent from Nr4a1(-/-) mice. Normal numbers of myeloid progenitor cells were present in Nr4a1(-/-) mice, which indicated that the defect occurred during later stages of monocyte development. The defect was cell intrinsic, as wild-type mice that received bone marrow from Nr4a1(-/-) mice developed fewer patrolling monocytes than did recipients of wild-type bone marrow. The Ly6C(-) monocytes remaining in the bone marrow of Nr4a1(-/-) mice were arrested in S phase of the cell cycle and underwent apoptosis. Thus, NR4A1 functions as a master regulator of the differentiation and survival of 'patrolling' Ly6C(-) monocytes.