CRISPR-Cas9-Mediated Epitope Tagging Provides Accurate and Versatile Assessment of Myocardin-Brief Report

Objective- Unreliable antibodies often hinder the accurate detection of an endogenous protein, and this is particularly true for the cardiac and smooth muscle cofactor, MYOCD (myocardin). Accordingly, the mouse Myocd locus was targeted with 2 independent epitope tags for the unambiguous expression, localization, and activity of MYOCD protein. Approach and Results- 3cCRISPR (3-component clustered regularly interspaced short palindromic repeat) was used to engineer a carboxyl-terminal 3×FLAG or 3×HA epitope tag in mouse embryos. Western blotting with antibodies to each tag revealed a MYOCD protein product of ≈150 kDa, a size considerably larger than that reported in virtually all publications. MYOCD protein was most abundant in some adult smooth muscle-containing tissues with surprisingly low-level expression in the heart. Both alleles of Myocd are active in aorta because a 2-fold increase in protein was seen in mice homozygous versus heterozygous for FLAG-tagged Myocd. ChIP (chromatin immunoprecipitation)-quantitative polymerase chain reaction studies provide proof-of-principle data demonstrating the utility of this mouse line in conducting genome-wide ChIP-seq studies to ascertain the full complement of MYOCD-dependent target genes in vivo. Although FLAG-tagged MYOCD protein was undetectable in sections of adult mouse tissues, low-passaged vascular smooth muscle cells exhibited expected nuclear localization. Conclusions- This report validates new mouse models for analyzing MYOCD protein expression, localization, and binding activity in vivo and highlights the need for rigorous authentication of antibodies in biomedical research.

A virtual tutor for children with autism

Purpose

The picture exchange communication system (PECS) is an established communication intervention for non-verbal children with autism. The purpose of this paper is to present an evaluation of a computer-based PECS approach, in which young non-verbal children with autism respond to an on-screen “virtual tutor” through the manipulation of picture/symbol cards. The paper presents research to investigate how the virtual tutor’s voice influences the children’s participation and performance.

Design/methodology/approach

Eight non-verbal children between six and nine years old and with a diagnosis of autism were presented with a series of computer-based activities, using a virtual tutor with either a natural or synthetic voice, in two separate sessions. Data were gathered using a within-participants counterbalanced design to control against variations between individuals and effects of presentation order.

Findings

Analysis of the children’s responses suggest that they were able to use the system more effectively when the virtual tutor had a synthetic voice, rather than a human voice. The findings demonstrate that a computer-based virtual tutor can provide an engaging method of supporting symbol-based communication for non-verbal children with autism, and that a synthetic voice type was preferable for the sessions undertaken.

Originality/value

Investigations of voice type and its influence on non-verbal children’s participation and performance have so far provided inconclusive results (Ramdoss, 2013). This research suggests that the voice type is an important feature of the learning experience of non-verbal children with autism, and can have a significant influence on their participation and performance in virtual tutor-led learning.

Deletion of P2Y2 receptor reveals a role for lymphotoxin-α in fatty streak formation

Background

Lymphotoxin alpha (LTα) is expressed in human atherosclerotic lesions and genetic variations in the LTα pathway have been linked to myocardial infarction. Activation of the P2Y₂ nucleotide receptor (P2Y₂R) regulates the production of LTα. in vitro. We aimed to uncover a potential pathway linking purinergic receptor to LTα-mediated inflammatory processes pivotal to the early stages of atherosclerosis in apolipoprotein E (ApoE^−/−) deficient mice.

Methods and results

En face immunostaining revealed that P2Y₂R and VCAM-1 are preferentially expressed in the atherosclerosis prone site of the mouse aortic sinus. Deletion of the P2Y₂R gene suppresses VCAM-1 expression. Compared with ApoE^−/−mice, ApoE^−/−mice lacking the P2Y₂R gene (ApoE^−/−/P2Y₂R^−/−) did not develop fatty streak lesions when fed a standard chow diet for 15 weeks. Systemic and CD4⁺ T cell production of the pro-inflammatory cytokine lymphotoxin-alpha (LTα) were specifically inhibited in ApoE^−/−/P2Y₂R^−/− mice. Anti-LTα preventive treatment was initiated in ApoE^−/− mice with intraperitoneal administration of recombinant human tumor necrosis factor receptor 1 fusion protein (TNFR1-Fc) on 5 consecutive days before the disease onset. Remarkably, none of the TNFR1:Fc-treated ApoE^−/− mice exhibited atherosclerotic lesions at any developmental stage.

Significance

ApoE^−/− mice deficient in P2Y₂R exhibit low endothelial cell VCAM-1 levels, decreased production of LTα and delayed onset of atherosclerosis. These data suggest that targeting this nucleotide receptor could be an effective therapeutic approach in atherosclerosis.

Paramagnetic centers in particulate formed from the oxidative pyrolysis of 1-methylnaphthalene in the presence of Fe(III)2O3 nanoparticles

The identity of radical species associated with particulate formed from the oxidative pyrolysis of 1-methylnaphthalene (1-MN) was investigated using low temperature matrix isolation electron paramagnetic resonance spectroscopy (LTMI-EPR), a specialized technique that provided a method of sampling and analysis of the gas-phase paramagnetic components. A superimposed EPR signal was identified to be a mixture of organic radicals (carbon and oxygen-centered) and soot. The carbon-centered radicals were identified as a mixture of the resonance-stabilized indenyl, cyclopentadienyl, and naphthalene 1-methylene radicals through the theoretical simulation of the radical's hyperfine structure. Formation of these radical species was promoted by the addition of Fe(III)2O3 nanoparticles. Enhanced formation of resonance stabilized radicals from the addition of Fe(III)2O3 nanoparticles can account for the observed increased sooting tendency associated with Fe(III)2O3 nanoparticle addition.

Amino acid sequence of bumblebee MCD peptide: a new mast cell degranulating peptide from the venom of the bumblebee Megabombus pennsylvanicus

A new 28 amino acid peptide, we recently isolated from the venom of the bumblebee Megabombus pennsylvanicus. has been characterized. The peptide, Met-Cys-Ile-Cys-Lys-Asn-Gly-Lys-Pro-Leu-Pro-Gly-Phe-Ile-Gly-Lys-Ile-Cys- Arg-Lys-Ile-Cys-Met-Met-Gln-Gln-Thr-His(NH2), has been named bumblebee mast cell degranulating (MCD) peptide due to its ability to degranulate rat peritoneal mast cells, and its resemblance to the bee venom MCD peptide. Bumblebee MCD peptide, unlike bombolitins, the other mast cell degranulating heptadecapeptides of bumblebee venom, is not lytic and releases histamine at a dose as low as 0.05 micrograms/ml (1.6 X 10(-8) M).