Improving CRISPR-Cas9 directed faithful transgene integration outcomes by reducing unwanted random DNA integration.

Background: The field of genome editing has been revolutionized by the development of an easily programmable editing tool, the CRISPR-Cas9. Despite its promise, off-target activity of Cas9 posed a great disadvantage for genome editing purposes by causing DNA double strand breaks at off-target locations and causing unwanted editing outcomes. Furthermore, for gene integration applications, which introduce transgene sequences, integration of transgenes to off-target sites could be harmful, hard to detect, and reduce faithful genome editing efficiency.

Maintenance of active chromatin states by HMGN2 is required for stem cell identity in a pluripotent stem cell model.

Background: Members of the HMGN protein family modulate chromatin structure and influence epigenetic modifications. HMGN1 and HMGN2 are highly expressed during early development and in the neural stem/progenitor cells of the developing and adult brain. Here, we investigate whether HMGN proteins contribute to the chromatin plasticity and epigenetic regulation that is essential for maintaining pluripotency in stem cells.

Amphetamine Dose-Dependently Decreases and Increases Binge Intake of Fat and Sucrose Independent of Sex.

Objective: Amphetamine was formerly used as a treatment to combat obesity, but amphetamine's use as an appetite suppressant was discontinued because of its significant abuse potential. Most of the rewarding and reinforcing effects of amphetamine differ by sex, with females showing higher levels of drug intake and amphetamine-induced motivation, relapse, and locomotion, but it is unknown whether amphetamine's effects on feeding also differ by sex. Furthermore, previous research on the anorectic effects of amphetamine has been focused primarily on its effects on baseline homeostatic feeding, but it is unknown whether amphetamine also affects hedonic, reward-related feeding, which is an important factor driving the rise in obesity levels.

Alpha-melanocyte stimulating hormone increases the activity of melanocortin-3 receptor-expressing neurons in the ventral tegmental area.

Key Points: Alpha-melanocyte stimulating hormone (α-MSH) is an anorexigenic peptide. Injection of the α-MSH analog MTII into the ventral tegmental area (VTA) decreases food and sucrose intake and food reward. Melanocortin-3 receptors (MC3R) are highly expressed in the VTA, suggesting that the effects of intra-VTA α-MSH may be mediated by α-MSH changing the activity of MC3R-expressing VTA neurons.

Determining training and education needs pertaining to highly infectious disease preparedness and response: A gap analysis survey of US emergency medical services practitioners.

Background: The Ebola virus disease outbreak highlighted the lack of consistent guidelines and training for workers outside of hospital settings. Specifically, emergency medical services (EMS) workers, who are frequently the first professionals to evaluate patients, often do not have advanced notice of patient diagnosis, and have limited time in their national curricula devoted to highly infectious disease (HID) identification and containment. All of these can place them at increased risk.

Neuropeptide-Y alters VTA dopamine neuron activity through both pre- and postsynaptic mechanisms.

The mesocorticolimbic dopamine system, the brain's reward system, regulates many different behaviors including food intake, food reward, and feeding-related behaviors, and there is increasing evidence that hypothalamic feeding-related neuropeptides alter dopamine neuron activity to affect feeding. For example, neuropeptide-Y (NPY), a strong orexigenic hypothalamic neuropeptide, increases motivation for food when injected into the ventral tegmental area (VTA). How NPY affects the activity of VTA dopamine neurons to regulate feeding behavior is unknown, however.

Retrogradely Transported TrkA Endosomes Signal Locally within Dendrites to Maintain Sympathetic Neuron Synapses.

Sympathetic neurons require NGF from their target fields for survival, axonal target innervation, dendritic growth and formation, and maintenance of synaptic inputs from preganglionic neurons. Target-derived NGF signals are propagated retrogradely, from distal axons to somata of sympathetic neurons via TrkA signaling endosomes. We report that a subset of TrkA endosomes that are transported from distal axons to cell bodies translocate into dendrites, where they are signaling competent and move bidirectionally, in close proximity to synaptic protein clusters.

Reprogramming of human fibroblasts toward a cardiac fate.

Reprogramming of mouse fibroblasts toward a myocardial cell fate by forced expression of cardiac transcription factors or microRNAs has recently been demonstrated. The potential clinical applicability of these findings is based on the minimal regenerative potential of the adult human heart and the limited availability of human heart tissue. An initial but mandatory step toward clinical application of this approach is to establish conditions for conversion of adult human fibroblasts to a cardiac phenotype.

Unique reporter-based sensor platforms to monitor signalling in cells.

Introduction: In recent years much progress has been made in the development of tools for systems biology to study the levels of mRNA and protein, and their interactions within cells. However, few multiplexed methodologies are available to study cell signalling directly at the transcription factor level.

Methods: Here we describe a sensitive, plasmid-based RNA reporter methodology to study transcription factor activation in mammalian cells, and apply this technology to profiling 60 transcription factors in parallel.

The chromatin-binding protein HMGN3 stimulates histone acetylation and transcription across the Glyt1 gene.

HMGNs are nucleosome-binding proteins that alter the pattern of histone modifications and modulate the binding of linker histones to chromatin. The HMGN3 family member exists as two splice forms, HMGN3a which is full-length and HMGN3b which lacks the C-terminal RD (regulatory domain). In the present study, we have used the Glyt1 (glycine transporter 1) gene as a model system to investigate where HMGN proteins are bound across the locus in vivo, and to study how the two HMGN3 splice variants affect histone modifications and gene expression.

A cluster of amyotrophic lateral sclerosis in New Hampshire: a possible role for toxic cyanobacteria blooms.

Cyanobacteria produce many neurotoxins including beta-methylamino-L-alanine (BMAA) that has been liked to amyotrophic lateral sclerosis (ALS) and neurodegenerative disease. A number of ALS cases have been diagnosed among residents of Enfield, NH, a town encompassing a lake with a history of cyanobacteria algal blooms. To investigate an association between toxic cyanobacterial blooms in New Hampshire and development of ALS, we reviewed records from our institution and other community databases to obtain demographic information on patients diagnosed with ALS within New England.

The impact of the human DNA topoisomerase II C-terminal domain on activity.

Background: Type II DNA topoisomerases (topos) are essential enzymes needed for the resolution of topological problems that occur during DNA metabolic processes. Topos carry out an ATP-dependent strand passage reaction whereby one double helix is passed through a transient break in another. Humans have two topoII isoforms, alpha and beta, which while enzymatically similar are differentially expressed and regulated, and are thought to have different cellular roles.

Chromosomal protein HMGN1 modulates the expression of N-cadherin.

HMGN1 is a nuclear protein that binds to nucleosomes and alters the accessibility of regulatory factors to their chromatin targets. To elucidate its biological function and identify specific HMGN1 target genes, we generated Hmgn1-/- mice. DNA microarray analysis of Hmgn1+/+ and Hmgn1-/- embryonic fibroblasts identified N-cadherin as a potential HMGN1 gene target.

Chromosomal protein HMGN1 enhances the acetylation of lysine 14 in histone H3.

The acetylation levels of lysine residues in nucleosomes, which are determined by the opposing activities of histone acetyltransferases (HATs) and deacetylases, play an important role in regulating chromatin-related processes, including transcription. We report that HMGN1, a nucleosomal binding protein that reduces the compaction of the chromatin fiber, increases the levels of acetylation of K14 in H3. The levels of H3K14ac in Hmgn1-/- cells are lower than in Hmgn1+/+ cells.