Connexin43 Mimetic Peptide Improves Retinal Function and Reduces Inflammation in a Light-Damaged Albino Rat Model

PURPOSE. Drugs that regulate connexin43 (Cx43) gap junction channels can reduce the spread of injury and improve functional outcomes after nervous system trauma. In the eye, Cx43 expression increases in the choroid following light damage. The aim of this study was to investigate whether Cx43 hemichannel block could preserve retinal function postinjury. METHODS. Light damage was induced by exposure of adult albino Sprague-Dawley rats to 2700 Lux light for 24 hours. Intravitreal injections of a Cx43 mimetic peptide hemichannel blocker, Peptide5, or sham were administered 2 hours after the onset and at the end of the light damage period. Retinal function was assessed by electroretinogram and inflammatory responses in the choroid and retina were assessed using immunohistochemistry (ionized calcium binding adaptor molecule 1 [Iba-1], leukocyte common antigen [CD45], glial fibrillary acidic protein [GFAP]). RESULTS. Light-damaged rat eyes had (1) reduced neuronal responses in both the rod and cone pathways and (2) marked inflammatory responses in the choroid and retina. Peptide5 significantly preserved function of photoreceptoral and postphotoreceptoral neurons in these animals. This was evident 24 hours after injury and 2 weeks later, as shown by improved mixed a-wave and mixed b-wave amplitudes, isolated rod PII and PIII amplitudes, and cone PII responses when compared with sham-treated controls. Retinal thinning and inflammation were also significantly reduced in Peptide5-treated eyes when compared with sham-treated controls. CONCLUSIONS. Blocking Cx43 hemichannels after light damage can significantly improve functional outcomes of neurons in both the rod and cone photo-transduction pathways in the light-damaged animal model, likely by reducing choroid inflammation and suppressing the glial-mediated inflammatory response. These data may have relevance for the treatment of conditions such as diabetic retinopathy and age-related macular degeneration

MicroRNA degradation by a conserved target RNA regulates animal behavior

International audiencemicroRNAs (miRNAs) repress target transcripts through partial complementarity. By contrast, highly complementary miRNA-binding sites within viral and artificially engineered transcripts induce miRNA degradation in vitro and in cell lines. Here, we show that a genome-encoded transcript harboring a near-perfect and deeply conserved miRNA-binding site for miR-29 controls zebrafish and mouse behavior. This transcript originated in basal vertebrates as a long noncoding RNA (lncRNA) and evolved to the protein-coding gene NREP in mammals, where the miR-29-binding site is located within the 3′ UTR. We show that the near-perfect miRNA site selectively triggers miR-29b destabilization through 3′ trimming and restricts its spatial expression in the cerebellum. Genetic disruption of the miR-29 site within mouse Nrep results in ectopic expression of cerebellar miR-29b and impaired coordination and motor learning. Thus, we demonstrate an endogenous target-RNA-directed miRNA degradation event and its requirement for animal behavio

Genomic copy number variation in Mus musculus.

BACKGROUND: Copy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously. RESULTS: We found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of CNV uniqueness (single sample occurrence) and the nature of CNV-gene overlap between wild-caught mice and classical laboratory strains. CNV-gene overlap was associated with lipid metabolism, pheromone response and olfaction compared to immunity, carbohydrate metabolism and amino-acid metabolism for wild-caught mice and classical laboratory strains, respectively. Using two subspecies of wild-caught Mus musculus, we identified putative CNVs unique to those subspecies and show this diversity is better captured by wild-derived laboratory strains than by the classical laboratory strains. A total of 9 genic copy number variable regions (CNVRs) were selected for experimental confirmation by droplet digital PCR (ddPCR). CONCLUSION: The analysis we present is a comprehensive, genome-wide analysis of CNVs in Mus musculus, which increases the number of known variants in the species and will accelerate the identification of novel variants in future studies

THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: G protein-coupled receptors

The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes over 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/bph.15538. G protein-coupled receptors are one of the six major pharmacological targets into which the Guide is divided, with the others being: ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2021, and supersedes data presented in the 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate

The NEWMEDS rodent touchscreen test battery for cognition relevant to schizophrenia.

RATIONALE: The NEWMEDS initiative (Novel Methods leading to New Medications in Depression and Schizophrenia, http://www.newmeds-europe.com ) is a large industrial-academic collaborative project aimed at developing new methods for drug discovery for schizophrenia. As part of this project, Work package 2 (WP02) has developed and validated a comprehensive battery of novel touchscreen tasks for rats and mice for assessing cognitive domains relevant to schizophrenia. OBJECTIVES: This article provides a review of the touchscreen battery of tasks for rats and mice for assessing cognitive domains relevant to schizophrenia and highlights validation data presented in several primary articles in this issue and elsewhere. METHODS: The battery consists of the five-choice serial reaction time task and a novel rodent continuous performance task for measuring attention, a three-stimulus visual reversal and the serial visual reversal task for measuring cognitive flexibility, novel non-matching to sample-based tasks for measuring spatial working memory and paired-associates learning for measuring long-term memory. RESULTS: The rodent (i.e. both rats and mice) touchscreen operant chamber and battery has high translational value across species due to its emphasis on construct as well as face validity. In addition, it offers cognitive profiling of models of diseases with cognitive symptoms (not limited to schizophrenia) through a battery approach, whereby multiple cognitive constructs can be measured using the same apparatus, enabling comparisons of performance across tasks. CONCLUSION: This battery of tests constitutes an extensive tool package for both model characterisation and pre-clinical drug discovery.This work was supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 115008 of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013). The authors thank Charlotte Oomen for valuable comments on the manuscript.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4007-

Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

Does autonomic arousal distinguish good and bad decisions? Healthy individuals’ skin conductance reactivity during the Iowa Gambling Task

Original article can be found at: http://psycontent.metapress.com/ Copyright Hogrefe & HuberThe Somatic Marker Hypothesis (SMH) proposes that physiological feedback to the brain influences cognitive appraisal and decision-making; however, the strength of evidence in support of the SMH is equivocal. In this study we examined the validity of the SMH by measuring physiological arousal in a population of healthy individuals playing the Iowa Gambling Task (IGT); a computerised card game designed to assess real-life decisionmaking. We also aimed to clarify uncertainty regarding the influence of reinforcer type and impulsiveness to IGT performance and the SMH. Skin conductance level (SCL) and heart rate reactivity were measured in forty-one participants performing the IGT using either facsimile or real money. Participants were categorised as non-impaired or impaired on the basis of their IGT performance, and any differences in performance and physiological between groups were examined. Heart rate data did not reveal any effects. Robust differences in SCL reactivity during the task were not found between impaired and nonimpaired individuals; however, marginal SCL rises were observed when non-impaired individuals anticipated and received a reward from disadvantageous choices compared with advantageous ones. This effect was found only when using facsimile money and did not occur in impaired individuals, suggesting some effect of reinforcer type on physiological activity and performance, and a difference in the physiology of impaired and non-impaired individuals. No significant differences in impulsiveness were found between impaired and non-impaired individuals. The findings suggest that autonomic activity is independent of long-term good or bad decision-making, and may reflect differences between decks in the magnitude of gain and loss. It is concluded that further substantiating evidence is needed for the SMH to continue as an explanation for human decision-making.Peer reviewe

Stretchable Electronics Based on Laser Structured, Vapor Phase Polymerized PEDOT/Tosylate

The fabrication of stretchable conductive material through vapor phase polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) is presented alongside a method to easily pattern these materials with nanosecond laser structuring. The devices were constructed from sheets of vapor phase polymerized PEDOT doped with tosylate on pre-stretched elastomeric substrates followed by laser structuring to achieve the desired geometrical shape. Devices were characterized for electrical conductivity, morphology, and electrical integrity in response to externally applied strain. Fabricated PEDOT sheets displayed a conductivity of 53.1 ± 1.2 S cm−1; clear buckling in the PEDOT microstructure was observed as a result of pre-stretching the underlying elastomeric substrate; and the final stretchable electronic devices were able to remain electrically conductive with up to 100% of externally applied strain. The described polymerization and fabrication steps achieve highly processable and patternable functional conductive polymer films, which are suitable for stretchable electronics due to their ability to withstand externally applied strains of up to 100%

In Vitro Wounding Models Using the Electric Cell-Substrate Impedance Sensing (ECIS)-Zθ Technology

Electric Cell-Substrate Impedance Sensing (ECIS) can produce reproducible wounding models by mechanically disrupting a cell monolayer. This study compared in vitro wound-healing using human cerebral microvascular endothelial cells (hCMVEC) with both single electrode (8W1E) and multiple electrodes (8W10E+) arrays. Measurements of hCMVEC migration and barrier functions were conducted, revealing variable levels of barrier disruption could be achieved by altering the duration and magnitude of the applied current. In all scenarios, the barrier (Rb) did not recover the strength observed prior to injury. Localization of junctional proteins following wounding were analyzed by immunocytochemistry. Following wounding, cell migration was generally faster on the 8W10E+ than the 8W1E array. Immunohistochemical analysis revealed non-viable cells remained on the 8W1E electrodes but not the 8W10E+ electrodes. However, viable cells partially remained on the 8W10E+ electrodes following wounding. In addition, the 8W10E+ electrodes demonstrated variation in cell loss across electrodes within the same well. This suggests the type of wounding is different on the two array types. However, our data show both arrays can be used to model incomplete barrier recovery and therefore both have potential for testing of drugs to improve endothelial barrier function. This is the first time that the possibility of using the 8W10E+ array as a wounding model is addressed. We highlight the differences in wounding produced between the two arrays, and can be used to study the underlying causes for impaired barrier function following CNS injuries

The Importance of Multifrequency Impedance Sensing of Endothelial Barrier Formation Using ECIS Technology for the Generation of a Strong and Durable Paracellular Barrier

In this paper, we demonstrate the application of electrical cell-substrate impedance sensing (ECIS) technology for measuring differences in the formation of a strong and durable endothelial barrier model. In addition, we highlight the capacity of ECIS technology to model the parameters of the physical barrier associated with (I) the paracellular space (referred to as Rb) and (II) the basal adhesion of the endothelial cells (α, alpha). Physiologically, both parameters are very important for the correct formation of endothelial barriers. ECIS technology is the only commercially available technology that can measure and model these parameters independently of each other, which is important in the context of ascertaining whether a change in overall barrier resistance (R) occurs because of molecular changes in the paracellular junctional molecules or changes in the basal adhesion molecules. Finally, we show that the temporal changes observed in the paracellular Rb can be associated with changes in specific junctional proteins (CD144, ZO-1, and catenins), which have major roles in governing the overall strength of the junctional communication between neighbouring endothelial cells