Chromatin Reprogramming of In Vitro Fertilized and Somatic Cell Nuclear Transfer Bovine Embryos During Embryonic Genome Activation.

Reprogramming of the gamete into a developmentally competent embryo identity is a fundamental aspect of preimplantation development. One of the most important processes of this reprogramming is the transcriptional awakening during embryonic genome activation (EGA), which robustly occurs in fertilized embryos but is defective in most somatic cell nuclear transfer (SCNT) embryos. However, little is known about the genome-wide underlying chromatin landscape during EGA in SCNT embryos and how it differs from a fertilized embryo.

Multiple repeat regions within mouse DUX recruit chromatin regulators to facilitate an embryonic gene expression program.

The embryonic transcription factor DUX regulates chromatin opening and gene expression in totipotent cleavage-stage mouse embryos, and its expression in embryonic stem cells promotes their conversion to 2-cell embryo-like cells (2CLCs) with extraembryonic potential. However, little is known regarding which domains within mouse DUX interact with particular chromatin and transcription regulators. Here, we reveal that the C-terminus of mouse DUX contains five uncharacterized ~100 amino acid (aa) repeats followed by an acidic 14 amino acid tail.

p53 convergently activates Dux/DUX4 in embryonic stem cells and in facioscapulohumeral muscular dystrophy cell models.

In mammalian embryos, proper zygotic genome activation (ZGA) underlies totipotent development. Double homeobox (DUX)-family factors participate in ZGA, and mouse Dux is required for forming cultured two-cell (2C)-like cells. Remarkably, in mouse embryonic stem cells, Dux is activated by the tumor suppressor p53, and Dux expression promotes differentiation into expanded-fate cell types.

Innovative teaching knowledge stays with users.

Programs seeking to transform undergraduate science, technology, engineering, and mathematics courses often strive for participating faculty to share their knowledge of innovative teaching practices with other faculty in their home departments. Here, we provide interview, survey, and social network analyses revealing that faculty who use innovative teaching practices preferentially talk to each other, suggesting that greater steps are needed for information about innovative practices to reach faculty more broadly.

DUX4 Suppresses MHC Class I to Promote Cancer Immune Evasion and Resistance to Checkpoint Blockade.

Advances in cancer immunotherapies make it critical to identify genes that modulate antigen presentation and tumor-immune interactions. We report that DUX4, an early embryonic transcription factor that is normally silenced in somatic tissues, is re-expressed in diverse solid cancers. Both cis-acting inherited genetic variation and somatically acquired mutations in trans-acting repressors contribute to DUX4 re-expression in cancer.

Facioscapulohumeral dystrophy: activating an early embryonic transcriptional program in human skeletal muscle.

Facioscapulohumeral dystrophy (FSHD) is the third most prevalent muscular dystrophy. A progressive disease, it presents clinically as weakness and wasting of the face, shoulder and upper arm muscles, with later involvement of the trunk and lower extremities. FSHD develops through complex genetic and epigenetic events that converge on a common mechanism of toxicity with mis-expression of the transcription factor double homeobox 4 (DUX4).

NuRD and CAF-1-mediated silencing of the D4Z4 array is modulated by DUX4-induced MBD3L proteins.

The DUX4 transcription factor is encoded by a retrogene embedded in each unit of the D4Z4 macrosatellite repeat. DUX4 is normally expressed in the cleavage-stage embryo, whereas chromatin repression prevents DUX4 expression in most somatic tissues. Failure of this repression causes facioscapulohumeral muscular dystrophy (FSHD) due to mis-expression of DUX4 in skeletal muscle.

BET bromodomain inhibitors and agonists of the beta-2 adrenergic receptor identified in screens for compounds that inhibit DUX4 expression in FSHD muscle cells.

Background: Facioscapulohumeral dystrophy (FSHD) is a progressive muscle disease caused by mutations that lead to epigenetic derepression and inappropriate transcription of the double homeobox 4 (DUX4) gene in skeletal muscle. Drugs that enhance the repression of DUX4 and prevent its expression in skeletal muscle cells therefore represent candidate therapies for FSHD.

Methods: We screened an aggregated chemical library enriched for compounds with epigenetic activities and the Pharmakon 1600 library composed of compounds that have reached clinical testing to identify molecules that decrease DUX4 expression as monitored by the levels of DUX4 target genes in FSHD patient-derived skeletal muscle cell cultures.

DUX4-induced dsRNA and MYC mRNA stabilization activate apoptotic pathways in human cell models of facioscapulohumeral dystrophy.

Facioscapulohumeral dystrophy (FSHD) is caused by the mis-expression of DUX4 in skeletal muscle cells. DUX4 is a transcription factor that activates genes normally associated with stem cell biology and its mis-expression in FSHD cells results in apoptosis. To identify genes and pathways necessary for DUX4-mediated apoptosis, we performed an siRNA screen in an RD rhabdomyosarcoma cell line with an inducible DUX4 transgene.

Model systems of DUX4 expression recapitulate the transcriptional profile of FSHD cells.

Facioscapulohumeral dystrophy (FSHD) is caused by the mis-expression of the double-homeodomain transcription factor DUX4 in skeletal muscle cells. Many different cell culture models have been developed to study the pathophysiology of FSHD, frequently based on endogenous expression of DUX4 in FSHD cells or by mis-expression of DUX4 in control human muscle cells. Although results generated using each model are generally consistent, differences have also been reported, making it unclear which model(s) faithfully recapitulate DUX4 and FSHD biology.

Assessing the STEM landscape: the current instructional climate survey and the evidence-based instructional practices adoption scale.

Background: The efficacy of active learning within STEM education is clear, and many institutions are working to help faculty adopt evidence-based instructional practices (EBIPs) which can promote active learning. In order to know the current status of our campus regarding these goals, measures of current instructional climate and the adoption of evidence-based instructional practices (EBIPs) are desired.

Results: Using a campus-wide online survey approach with remuneration for faculty participants, the 28-item current instructional climate survey (CICS) and the 6-item EBIP adoption scale were developed.

Faculty drivers and barriers: laying the groundwork for undergraduate STEM education reform in academic departments.

Background: Calls to improve student learning and increase the number of science, technology, engineering, and math (STEM) college and university graduates assert the need for widespread adoption of evidence-based instructional practices in undergraduate STEM courses. For successful reforms to take hold and endure, it is likely that a significant shift in culture around teaching is needed. This study seeks to describe the initial response of faculty to an effort to shift teaching norms, with a long-term goal of altering the culture around teaching and learning in STEM.

Increased DUX4 expression during muscle differentiation correlates with decreased SMCHD1 protein levels at D4Z4.

Facioscapulohumeral muscular dystrophy is caused by incomplete epigenetic repression of the transcription factor DUX4 in skeletal muscle. A copy of DUX4 is located within each unit of the D4Z4 macrosatellite repeat array and its derepression in somatic cells is caused by either repeat array contraction (FSHD1) or by mutations in the chromatin repressor SMCHD1 (FSHD2). While DUX4 expression has thus far only been detected in FSHD muscle and muscle cell cultures, and increases with in vitro myogenic differentiation, the D4Z4 chromatin structure has only been studied in proliferating myoblasts or non-myogenic cells.

KDM5B regulates embryonic stem cell self-renewal and represses cryptic intragenic transcription.

Although regulation of histone methylation is believed to contribute to embryonic stem cell (ESC) self-renewal, the mechanisms remain obscure. We show here that the histone H3 trimethyl lysine 4 (H3K4me3) demethylase, KDM5B, is a downstream Nanog target and critical for ESC self-renewal. Although KDM5B is believed to function as a promoter-bound repressor, we find that it paradoxically functions as an activator of a gene network associated with self-renewal.

Sulfur K-edge spectroscopic investigation of second coordination sphere effects in oxomolybdenum-thiolates: relationship to molybdenum-cysteine covalency and electron transfer in sulfite oxidase.

Second-coordination sphere effects such as hydrogen bonding and steric constraints that provide for specific geometric configurations play a critical role in tuning the electronic structure of metalloenzyme active sites and thus have a significant effect on their catalytic efficiency. Crystallographic characterization of vertebrate and plant sulfite oxidase (SO) suggests that an average O(oxo)-Mo-S(Cys)-C dihedral angle of approximately 77 degrees exists at the active site of these enzymes. This angle is slightly more acute (approximately 72 degrees) in the bacterial sulfite dehydrogenase (SDH) from Starkeya novella.

Prevention of chronic anthracycline cardiotoxicity in the adult Fischer 344 rat by dexrazoxane and effects on iron metabolism.

Purpose: Anthracyclines, such as doxorubicin and daunorubicin, continue to be widely used in the treatment of cancer, although they share the adverse effect of chronic, cumulative dose-related cardiotoxicity. The only approved treatment in prevention of anthracycline cardiotoxicity is dexrazoxane, a putative iron chelator. Previous in vitro studies have shown that disorders of iron metabolism, including altered IRP1-IRE binding, may be an important mechanism of anthracycline cardiotoxicity.

Reduction of 13-deoxydoxorubicin and daunorubicinol anthraquinones by human carbonyl reductase.

Carbonyl reductase (CR) catalyzes the nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reduction of several carbonyls. Anthracyclines used to treat cancer are reduced by CR at the C13 carbonyl and the resulting metabolites are implicated in the cardiotoxicity associated with anthracycline therapy. CR also is believed to have a role in detoxifying quinones, raising the question whether CR catalyzes reduction of anthracycline quinones.

Doxorubicin cardiac dysfunction: effects on calcium regulatory proteins, sarcoplasmic reticulum, and triiodothyronine.

Utilizing a model of chronic doxorubicin cardiomyopathy, this study examines the relationship between changes in expression and function of calcium handling proteins and contractile dysfunction. A possible mechanism to account for this relationship is suggested. New Zealand white rabbits were injected with either doxorubicin (1 mg/kg, twice weekly for 8 wk) or 0.

S K-edge X-ray absorption studies of tetranuclear iron-sulfur clusters: mu-sulfide bonding and its contribution to electron delocalization.

X-ray absorption spectroscopy (XAS) at the sulfur ( approximately 2470 eV) and chlorine ( approximately 2822 eV) K-edges has been applied to a series of 4Fe-4S model complexes. These are compared to 2Fe-2S model complexes to obtain insight into the localized ground state in the mixed-valence dimer versus the delocalized ground state in the mixed-valence tetramer. The preedges of hypothetical delocalized mixed-valence dimers [Fe(2)S(2)](+) are estimated using trends from experimental data and density functional calculations, for comparison to the delocalized mixed-valence tetramer [Fe(4)S(4)](2+).

Sarcoplasmic reticulum calcium release is stimulated and inhibited by daunorubicin and daunorubicinol.

Cardiac effects of anthracyclines or their metabolites may include both the stimulation and inhibition of Ca(2+) release from sarcoplasmic reticulum. In this study, the ability of daunorubicin and its primary metabolite, daunorubicinol, to stimulate and inhibit Ca(2+) release from canine sarcoplasmic reticulum (SR) vesicles was investigated. It was observed that both daunorubicin and daunorubicinol were several fold more potent at inhibiting than they were at stimulating SR Ca(2+) release.

Daunorubicin cardiotoxicity: evidence for the importance of the quinone moiety in a free-radical-independent mechanism.

Anthracyclines, such as daunorubicin (Daun), and other quinone-containing compounds can stimulate the formation of toxic free radicals. The present study tests the hypothesis that the quinone moiety of Daun, by increasing free-radical production, disrupts sarcoplasmic reticulum (SR) function and thereby inhibits myocardial contractility in vitro. We compared Daun with its quinone-deficient analogue, 5-iminodaunorubicin (5-ID), using experimental interventions to produce various contractile states that depend on SR function.