Michael P O'Quinn

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AIM Gap-junctional connexin43 (Cx43) has roles in multiple aspects of skin wound healing - including scarring. The aim here was to study the effects of a cell-permeant peptide from the Cx43 carboxyl-terminus (CT) on scarring and regeneration following cutaneous injury. MATERIALS & METHODS The effects of Cx43 CT peptide were studied in mouse and pig models(More)
RATIONALE Remodeling of connexin (Cx)43 gap junctions (GJs) is linked to ventricular arrhythmia. OBJECTIVES A peptide mimetic of the carboxyl terminal (CT) of Cx43, incorporating a postsynaptic density-95/disks-large/ZO-1 (PDZ)-binding domain, reduces Cx43/ZO-1 interaction and GJ size remodeling in vitro. Here, we determined: (1) whether the Cx43-CT(More)
Fibrotic scars deposited during skin wound healing can cause disfiguration and loss of dermal function. Scar differentiation involves inputs from multiple cell types in a predictable and overlapping sequence of cellular events that includes inflammation, migration/proliferation and extracellular matrix deposition. Research into the molecular mechanisms(More)
The NCX1 gene contains three promoters (H1, K1, and Br1), and as a result of alternative promoter usage and alternative splicing, there are multiple tissue-specific variants of the Na(+)-Ca(2+) exchanger. We have proposed that for NCX1, the H1 promoter regulates expression in the heart, the K1 promoter regulates expression in the kidney, and the Br1(More)
A major limitation in studies of the injured heart is animal-to-animal variability in wound size resulting from commonly used techniques such as left anterior descending coronary artery ligation. This variability can make standard errors sufficiently large that mean separation between treatment and control groups can be difficult without replicating numbers(More)
The disruption of the spatial order of electromechanical junctions at myocyte-intercalated disks (ICDs) is a poorly understood characteristic of many cardiac disease states. Here, in vitro and in vivo evidence is provided that zonula occludens-1 (ZO-1) regulates the organization of gap junctions (GJs) and adherens junctions (AJs) at ICDs. We investigated(More)
Intercellular connectivity mediated by gap junctions (GJs) composed of connexin43 (Cx43) is critical to the function of excitable tissues such as the heart and brain. Disruptions to Cx43 GJ organization are thought to be a factor in cardiac arrhythmias and are also implicated in epilepsy. This article is based on a presentation to the 4th Larry and Horti(More)
This study examined transgenic mice whose expression of a β-galactosidase (lacZ) reporter is driven by a GATA6 gene enhancer. Previous investigations established that transcription of the transgene was associated with precardiac mesoderm and primary heart tube myocardium, which decreased progressively, so that its expression was no longer observed within(More)
Broken heart syndrome, also known as takotsubo cardiomyopathy, is a syndrome characterized by a transient regional systolic dysfunction of the left ventricle associated to a psychological stress. We herein describe a case of a 23-year-old female habitual marijuana user who was resuscitated after cardiac arrest and then diagnosed with midventricular stress(More)
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