Molecular layer disinhibition unlocks climbing-fiber-instructed motor learning in the cerebellum.

Climbing fibers supervise cerebellar learning by providing signals to Purkinje cells (PCs) that instruct adaptive changes to mistakenly performed movements. Yet, climbing fibers are regularly active, even during well performed movements, suggesting that a mechanism dynamically regulates the ability of climbing fibers to induce corrective plasticity in response to motor errors. We found that molecular layer interneurons (MLIs), whose inhibition of PCs powerfully opposes climbing-fiber-mediated excitation, serve this function.

Epoxyeicosatrienoic acid analog EET-B attenuates post-myocardial infarction remodeling in spontaneously hypertensive rats.

Epoxyeicosatrienoic acids (EETs) and their synthetic analogs have cardiovascular protective effects. Here, we investigated the action of a novel EET analog EET-B on the progression of post-myocardial infarction (MI) heart failure in spontaneously hypertensive rats (SHR). Adult male SHR were divided into vehicle- and EET-B (10 mg/kg/day; p.

Discs large 1 controls daughter-cell polarity after cytokinesis in vertebrate morphogenesis.

Vertebrate embryogenesis and organogenesis are driven by cell biological processes, ranging from mitosis and migration to changes in cell size and polarity, but their control and causal relationships are not fully defined. Here, we use the developing limb skeleton to better define the relationships between mitosis and cell polarity. We combine protein-tagging and -perturbation reagents with advanced in vivo imaging to assess the role of Discs large 1 (Dlg1), a membrane-associated scaffolding protein, in mediating the spatiotemporal relationship between cytokinesis and cell polarity.

Infarct size-limiting effect of epoxyeicosatrienoic acid analog EET-B is mediated by hypoxia-inducible factor-1α via downregulation of prolyl hydroxylase 3.

Epoxyeicosatrienoic acids (EETs) decrease cardiac ischemia-reperfusion injury; however, the mechanism of their protective effect remains elusive. Here, we investigated the cardioprotective action of a novel EET analog, EET-B, in reperfusion and the role of hypoxia-inducible factor (HIF)-1α in such action of EET-B. Adult male rats were subjected to 30 min of left coronary artery occlusion followed by 2 h of reperfusion.

A novel fibroblast growth factor-1 ligand with reduced heparin binding protects the heart against ischemia-reperfusion injury in the presence of heparin co-administration.

Aims: Fibroblast growth factor 1 (FGF1), a heparin/heparan sulfate-binding growth factor, is a potent cardioprotective agent against myocardial infarction (MI). The impact of heparin, the standard of care for MI patients entering the emergency room, on cardioprotective effects of FGF1 is unknown, however.

Methods And Results: To address this, a rat model of MI was employed to compare cardioprotective potentials (lower infarct size and improve post-ischemic function) of native FGF1 and an engineered FGF1 (FGF1ΔHBS) with reduced heparin-binding affinity when given at the onset of reperfusion in the absence or presence of heparin.

Transient receptor potential vanilloid 1 inhibitors block laparotomy- and opioid-induced infarct size reduction in rats.

Background And Purpose: In light of the opioid epidemic, physicians are increasingly prescribing non-opioid analgesics to surgical patients. Transient receptor potential vanilloid 1 (TRPV1) inhibitors are potentially alternative pain therapeutics for surgery. Here, we examined in rodents whether the cardioprotection conferred by two common procedures during surgery, a laparotomy or morphine delivery, is mediated by the TRPV1 channel.

RasIns: Genetically Encoded Intrabodies of Activated Ras Proteins.

K- and H-Ras are the most commonly mutated genes in human tumors and are critical for conferring and maintaining the oncogenic phenotype in tumors with poor prognoses. Here, we design genetically encoded antibody-like ligands (intrabodies) that recognize active, GTP-bound K- and H-Ras. These ligands, which use the 10th domain of human fibronectin as their scaffold, are stable inside the cells and when fused with a fluorescent protein label, the constitutively active G12V mutant H-Ras.

Transient Receptor Potential Vanilloid 1 Regulates Mitochondrial Membrane Potential and Myocardial Reperfusion Injury.

Background: The transient receptor potential vanilloid 1 (TRPV1) mediates cellular responses to pain, heat, or noxious stimuli by calcium influx; however, the cellular localization and function of TRPV1 in the cardiomyocyte is largely unknown. We studied whether myocardial injury is regulated by TRPV1 and whether we could mitigate reperfusion injury by limiting the calcineurin interaction with TRPV1.

Methods And Results: In primary cardiomyocytes, confocal and electron microscopy demonstrates that TRPV1 is localized to the mitochondria.

Intestinal Microbial Metabolites Are Linked to Severity of Myocardial Infarction in Rats.

Intestinal microbiota determine severity of myocardial infarction in rats. We determined whether low molecular weight metabolites derived from intestinal microbiota and transported to the systemic circulation are linked to severity of myocardial infarction. Plasma from rats treated for seven days with the non-absorbed antibiotic vancomycin or a mixture of streptomycin, neomycin, polymyxin B and bacitracin was analyzed using mass spectrometry-based metabolite profiling platforms.

An E3-ligase-based method for ablating inhibitory synapses.

Although neuronal activity can be modulated using a variety of techniques, there are currently few methods for controlling neuronal connectivity. We introduce a tool (GFE3) that mediates the fast, specific and reversible elimination of inhibitory synaptic inputs onto genetically determined neurons. GFE3 is a fusion between an E3 ligase, which mediates the ubiquitination and rapid degradation of proteins, and a recombinant, antibody-like protein (FingR) that binds to gephyrin.

Visual Deprivation During the Critical Period Enhances Layer 2/3 GABAergic Inhibition in Mouse V1.

Unlabelled: The role of GABAergic signaling in establishing a critical period for experience in visual cortex is well understood. However, the effects of early experience on GABAergic synapses themselves are less clear. Here, we show that monocular deprivation (MD) during the adolescent critical period produces marked enhancement of GABAergic signaling in layer 2/3 of mouse monocular visual cortex.

Morphine Reduces Myocardial Infarct Size via Heat Shock Protein 90 in Rodents.

Opioids reduce injury from myocardial ischemia-reperfusion in humans. In experimental models, this mechanism involves GSK3β inhibition. HSP90 regulates mitochondrial protein import, with GSK3β inhibition increasing HSP90 mitochondrial content.

Thrombopoietin receptor agonists protect human cardiac myocytes from injury by activation of cell survival pathways.

Thrombopoietin confers immediate protection against injury caused by ischemia/reperfusion in the rat heart. Eltrombopag is a small molecule agonist of the thrombopoietin receptor, the physiologic target of thrombopoietin. However, the ability of eltrombopag and thrombopoietin to protect human cardiac myocytes against injury and the mechanisms underlying myocyte protection are not known.

Nociceptive-induced myocardial remote conditioning is mediated by neuronal gamma protein kinase C.

Deciphering the remote conditioning molecular mechanism may provide targets to develop therapeutics that can broaden the clinical application. To further investigate this, we tested whether two protein kinase C (PKC) isozymes, the ubiquitously expressed epsilon PKC (εPKC) and the neuronal-specific gamma PKC (γPKC), mediate nociceptive-induced remote myocardial conditioning. Male Sprague-Dawley rats were used for both in vivo and ex vivo myocardial ischemia-reperfusion protocols.

Recombinant probes for visualizing endogenous synaptic proteins in living neurons.

The ability to visualize endogenous proteins in living neurons provides a powerful means to interrogate neuronal structure and function. Here we generate recombinant antibody-like proteins, termed Fibronectin intrabodies generated with mRNA display (FingRs), that bind endogenous neuronal proteins PSD-95 and Gephyrin with high affinity and that, when fused to GFP, allow excitatory and inhibitory synapses to be visualized in living neurons. Design of the FingR incorporates a transcriptional regulation system that ties FingR expression to the level of the target and reduces background fluorescence.

X11/Mint genes control polarized localization of axonal membrane proteins in vivo.

Mislocalization of axonal proteins can result in misassembly and/or miswiring of neural circuits, causing disease. To date, only a handful of genes that control polarized localization of axonal membrane proteins have been identified. Here we report that Drosophila X11/Mint proteins are required for targeting several proteins, including human amyloid precursor protein (APP) and Drosophila APP-like protein (APPL), to axonal membranes and for their exclusion from dendrites of the mushroom body in Drosophila, a brain structure involved in learning and memory.

Roles of endothelial nitric oxide synthase (eNOS) and mitochondrial permeability transition pore (MPTP) in epoxyeicosatrienoic acid (EET)-induced cardioprotection against infarction in intact rat hearts.

We previously demonstrated that 11,12 and 14,15-epoxeicosatrienoic acids (EETs) produce cardioprotection against ischemia-reperfusion injury in dogs and rats. Several signaling mechanisms have been implicated in the cardioprotective actions of the EETs; however, their mechanisms remain largely elusive. Since nitric oxide (NO) plays a significant role in cardioprotection and EETs have been demonstrated to induce NO production in various tissues, we hypothesized that NO is involved in mediating the EET actions in cardioprotection.

Acute and chronic cardioprotection by the enkephalin analogue, Eribis peptide 94, is mediated via activation of nitric oxide synthase and adenosine triphosphate-regulated potassium channels.

Background/aims: Eribis peptide 94 (EP 94) is a new enkephalin derivative which potently binds to the µ- and δ-opioid receptor. In this study, we determined the effects of EP 94 and potential mechanism(s) involved in cardioprotection of the rat heart.

Methods And Results: An acute (5 and10 min into ischemia) and a chronic (24 h prior to ischemia) EP 94 administration produced a similar 30-40% reduction in infarct size/area at risk and the effects were blocked by the K(ATP) channel antagonists, HMR 1098 and 5-HD.

Factors mediating remote preconditioning of trauma in the rat heart: central role of the cytochrome p450 epoxygenase pathway in mediating infarct size reduction.

The present study further identified factors involved in the cardioprotective phenomenon of remote preconditioning of trauma (RPCT) with special emphasis on the role of the epoxyeicosatrienoic acids (EETs) in mediating this phenomenon. Remote preconditioning of trauma was produced by an abdominal incision only through the skin. Subsequently, all rats were subjected to 30 minutes of left coronary artery occlusion followed by 2 hours of reperfusion and the infarct size was determined.

Intestinal microbiota determine severity of myocardial infarction in rats.

Signals from the intestinal microbiota are important for normal host physiology; alteration of the microbiota (dysbiosis) is associated with multiple disease states. We determined the effect of antibiotic-induced intestinal dysbiosis on circulating cytokine levels and severity of ischemia/reperfusion injury in the heart. Treatment of Dahl S rats with a minimally absorbed antibiotic vancomycin, in the drinking water, decreased circulating leptin levels by 38%, resulted in smaller myocardial infarcts (27% reduction), and improved recovery of postischemic mechanical function (35%) as compared with untreated controls.

Eribis peptide 94 reduces infarct size in rat hearts via activation of centrally located μ opioid receptors.

Eribis peptide 94 (EP 94) is a novel enkephalin derivative that binds with high potency to μ and δ opioid receptors with less affinity for the κ opioid receptor. This compound has recently been shown to produce an acute reduction in myocardial infarct size in the anesthetized pig and rat partially via an endothelial nitric oxide synthase and KATP channel-dependent mechanism. EP 94 also was found to produce a chronic reduction in infarct size 24 hours postdrug administration via the upregulation of inducible nitric oxide synthase in rats.

Dose-dependent cardioprotection of enkephalin analogue Eribis peptide 94 and cardiac expression of opioid receptors in a porcine model of ischaemia and reperfusion.

Opioids confer cardioprotection after myocardial ischaemia and reperfusion. The primary aim of the present study was to evaluate the cardioprotective effect of different doses of enkephalin analogue Eribis peptide 94 (EP 94) in a porcine model of ischaemia and reperfusion. A secondary aim was to analyse the impact of ischaemia and reperfusion on the expression of opioid receptor subtypes in the porcine heart.

Protection from myocardial ischemia/reperfusion injury by a positive allosteric modulator of the A₃ adenosine receptor.

Adenosine is increased in ischemic tissues where it serves a protective role by activating adenosine receptors (ARs), including the A₃ AR subtype. We investigated the effect of N-{2-[(3,4-dichlorophenyl)amino]quinolin-4-yl}cyclohexanecarboxamide (LUF6096), a positive allosteric modulator of the A₃ AR, on infarct size in a barbital-anesthetized dog model of myocardial ischemia/reperfusion injury. Dogs were subjected to 60 min of coronary artery occlusion and 3 h of reperfusion.

Abdominal surgical incision induces remote preconditioning of trauma (RPCT) via activation of bradykinin receptors (BK2R) and the cytochrome P450 epoxygenase pathway in canine hearts.

Objective: Recently, a novel observation was made in which nonischemic trauma at a site remote from the heart produced by a transverse abdominal incision resulted in a marked reduction of infarct size (IS) in the mouse heart via activation of sensory nerve fibers in the skin and subsequent activation of bradykinin 2 receptors (BK2R). This phenomenon was termed remote preconditioning of trauma (RPCT). Since RPCT may have potential clinical implications we attempted to confirm these findings in a large animal model, the dog.

Characterization of a critical role for CFTR chloride channels in cardioprotection against ischemia/reperfusion injury.

Aim: To further characterize the functional role of cystic fibrosis transmembrane conductance regulator (CFTR) in early and late (second window) ischemic preconditioning (IPC)- and postconditioning (POC)-mediated cardioprotection against ischemia/reperfusion (I/R) injury.

Methods: CFTR knockout (CFTR(-/-)) mice and age- and gender-matched wild-type (CFTR(+/+)) and heterozygous (CFTR(+/-)) mice were used. In in vivo studies, the animals were subjected to a 30-min coronary occlusion followed by a 40-min reperfusion.