Loss Enhances Disease Progression in a Murine Model of Osteosarcoma.

Osteosarcoma is an aggressive bone malignancy, molecularly characterized by acquired genome complexity and frequent loss of and . Obtaining a molecular understanding of the initiating mutations of osteosarcomagenesis has been challenged by the difficulty of parsing between passenger and driver mutations in genes. Here, a forward genetic screen in a genetic mouse model of osteosarcomagenesis initiated by and conditional loss in pre-osteoblasts identified that loss contributes to OS progression.

Optogenetic stimulation of mouse Hoxb8 microglia in specific regions of the brain induces anxiety, grooming, or both.

Previously, we have shown that either disruption of the Hoxb8 gene or ablation of a microglial subpopulation, Hoxb8 microglia, results in mice exhibiting both chronic anxiety and OCSD-like behavior, compulsive pathological hair pulling (trichotillomania), to the point of showing lesions at the sites of overgrooming. Herein we show, that optogenetic stimulation of Hoxb8 microglia in specific regions of the brain induces elevated anxiety, grooming or both. Optogenetic stimulation of Hoxb8 microglia within the dorsomedial striatum (DMS) or the medial prefrontal cortex (mPFC) induces grooming, whereas stimulation of Hoxb8 microglia in the basolateral amygdala (BLA) or central amygdala (CeA) produces elevated anxiety.

Lrig1 expression identifies quiescent stem cells in the ventricular-subventricular zone from postnatal development to adulthood and limits their persistent hyperproliferation.

Background: We previously identified Leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1) as a marker of long-term neurogenic stem cells in the lateral wall of the adult mouse brain. The morphology of the stem cells thus identified differed from the canonical B1 type stem cells, raising a question about their cellular origin. Thus, we investigated the development of these stem cells in the postnatal and juvenile brain.

Defining the Hoxb8 cell lineage during murine definitive hematopoiesis.

Previously, we have demonstrated that a subpopulation of microglia, known as Hoxb8 microglia, is derived from the Hoxb8 lineage during the second wave (E8.5) of yolk sac hematopoiesis, whereas canonical non-Hoxb8 microglia arise from the first wave (E7.5).

ETV4 and ETV5 drive synovial sarcoma through cell cycle and DUX4 embryonic pathway control.

Synovial sarcoma is an aggressive malignancy with no effective treatments for patients with metastasis. The synovial sarcoma fusion SS18-SSX, which recruits the SWI/SNF-BAF chromatin remodeling and polycomb repressive complexes, results in epigenetic activation of FGF receptor (FGFR) signaling. In genetic FGFR-knockout models, culture, and xenograft synovial sarcoma models treated with the FGFR inhibitor BGJ398, we show that FGFR1, FGFR2, and FGFR3 were crucial for tumor growth.

Size and shape based chromosome separation in the inertial focusing device.

In this paper, we use a spiral channel inertial focusing device for isolation and purification of chromosomes, which are highly asymmetric. The method developed is proposed as a sample preparation process for transchromosomic research. The proposed microfluidics-based chromosome separation approach enables rapid, label-free isolation of bioactive chromosomes and is compatible with chromosome buffer.

Site-Specific Recombination with Inverted Target Sites: A Cautionary Tale of Dicentric and Acentric Chromosomes.

Site-specific recombinases are widely used tools for analysis of genetics, development, and cell biology, and many schemes have been devised to alter gene expression by recombinase-mediated DNA rearrangements. Because the and target sites for the commonly used FLP and Cre recombinases are asymmetrical, and must pair in the same direction to recombine, construct design must take into account orientation of the target sites. Both direct and inverted configurations have been used.

Lrig1 expression prospectively identifies stem cells in the ventricular-subventricular zone that are neurogenic throughout adult life.

Background: Leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1) regulates stem cell quiescence. As a marker, it identifies stem cells in multiple organs of the mouse. We had detected Lrig1 expression in cultured Id1 neural stem cells obtained from the lateral walls lining the lateral ventricles of the adult mouse brain.

Enhanced chromosome extraction from cells using a pinched flow microfluidic device.

Extraction and purification of intact chromosomes are critical sample preparation steps for transchromosomic research and other applications. The commonly used sample preparation methods lead to too few chromosomes with chromosome deactivation and degradation. In this paper, a "mild" chromosome extraction process that combines a chemical and mechanical lysis approach is introduced for the preparation of intact chromosomes that can readily be used for downstream processing.

A Microglia Sublineage Protects from Sex-Linked Anxiety Symptoms and Obsessive Compulsion.

Aberrant microglia activity is associated with many neurological and psychiatric disorders, yet our knowledge about the pathological mechanisms is incomplete. Here, we describe a genetically defined microglia sublineage in mice which has the ability to suppress obsessive compulsion and anxiety symptoms. These microglia derive from precursors expressing the transcription factor Hoxb8.

HDAC2 Regulates Site-Specific Acetylation of MDM2 and Its Ubiquitination Signaling in Tumor Suppression.

Histone deacetylases (HDACs) are promising targets for cancer therapy, although their individual actions remain incompletely understood. Here, we identify a role for HDAC2 in the regulation of MDM2 acetylation at previously uncharacterized lysines. Upon inactivation of HDAC2, this acetylation creates a structural signal in the lysine-rich domain of MDM2 to prevent the recognition and degradation of its downstream substrate, MCL-1 ubiquitin ligase E3 (MULE).

Silencing of retrotransposon-derived imprinted gene RTL1 is the main cause for postimplantational failures in mammalian cloning.

Substantial rates of fetal loss plague all in vitro procedures involving embryo manipulations, including human-assisted reproduction, and are especially problematic for mammalian cloning where over 90% of reconstructed nuclear transfer embryos are typically lost during pregnancy. However, the epigenetic mechanism of these pregnancy failures has not been well described. Here we performed methylome and transcriptome analyses of pig induced pluripotent stem cells and associated cloned embryos, and revealed that aberrant silencing of imprinted genes, in particular the retrotransposon-derived RTL1 gene, is the principal epigenetic cause of pregnancy failure.

Two distinct ontogenies confer heterogeneity to mouse brain microglia.

mutant mice show compulsive behavior similar to trichotillomania, a human obsessive-compulsive-spectrum disorder. The only lineage-labeled cells in the brains of mice are microglia, suggesting that defective microglia caused the disorder. What is the source of the microglia? It has been posited that all microglia progenitors arise at embryonic day (E) 7.

The SS18-SSX Oncoprotein Hijacks KDM2B-PRC1.1 to Drive Synovial Sarcoma.

Synovial sarcoma is an aggressive cancer invariably associated with a chromosomal translocation involving genes encoding the SWI-SNF complex component SS18 and an SSX (SSX1 or SSX2) transcriptional repressor. Using functional genomics, we identify KDM2B, a histone demethylase and component of a non-canonical polycomb repressive complex 1 (PRC1.1), as selectively required for sustaining synovial sarcoma cell transformation.

Paracrine osteoprotegerin and β-catenin stabilization support synovial sarcomagenesis in periosteal cells.

Synovial sarcoma (SS) is an aggressive soft-tissue sarcoma that is often discovered during adolescence and young adulthood. Despite the name, synovial sarcoma does not typically arise from a synoviocyte but instead arises in close proximity to bones. Previous work demonstrated that mice expressing the characteristic SS18-SSX fusion oncogene in myogenic factor 5-expressing (Myf5-expressing) cells develop fully penetrant sarcomagenesis, suggesting skeletal muscle progenitor cell origin.

The Influential Role of BCL2 Family Members in Synovial Sarcomagenesis.

Synovial sarcomas are deadly soft tissue malignancies associated with t(X;18) balanced chromosomal translocations. Expression of the apoptotic regulator BCL2 is prominent in synovial sarcomas and has prompted the hypothesis that synovial sarcomagenesis may depend on it. Herein, it is demonstrated that overexpression enhances synovial sarcomagenesis in an animal model.

Mouse fitness measures reveal incomplete functional redundancy of Hox paralogous group 1 proteins.

Here we assess the fitness consequences of the replacement of the Hoxa1 coding region with its paralog Hoxb1 in mice (Mus musculus) residing in semi-natural enclosures. Previously, this Hoxa1B1 swap was reported as resulting in no discernible embryonic or physiological phenotype (i.e.

Deep-brain imaging via epi-fluorescence Computational Cannula Microscopy.

Here we demonstrate widefield (field diameter = 200 μm) fluorescence microscopy and video imaging inside the rodent brain at a depth of 2 mm using a simple surgical glass needle (cannula) of diameter 0.22 mm as the primary optical element. The cannula guides excitation light into the brain and the fluorescence signal out of the brain.

Derivation of Transgene-Free Rat Induced Pluripotent Stem Cells Approximating the Quality of Embryonic Stem Cells.

Although a variety of reprogramming strategies have been reported to create transgene-free induced pluripotent stem (iPS) cells from differentiated cell sources, a fundamental question still remains: Can we generate safe iPS cells that have the full spectrum of features of corresponding embryonic stem (ES) cells? Studies in transgene-free mouse iPS cells have indicated a positive answer to this question. However, the reality is that no other species have a derived transgene-free iPS cell line that can truly mimic ES cell quality. Specifically, critical data for chimera formation and germline transmission are generally lacking.