Methamphetamine (MA) abuse is related to risks to the cardiovascular system. The present study aimed to compare the effects of moderate-intensity aerobic training (MIAT) and vitamin E (Vit.E) supplementation on markers of cardiac apoptosis following MA exposure.
View Article and Find Full Text PDFProf. Ugo Carraro reached 80 years of age on 23 February 2023, and we wish to celebrate him and his work by reviewing his lifetime of scientific achievements in Translational Myology. Currently, he is a Senior Scholar with the University of Padova, Italy, where, as a tenured faculty member, he founded the Interdepartmental Research Center of Myology.
View Article and Find Full Text PDFBackground: The potassium channel encoded by the (a) has been detected in the atrophying skeletal muscle of mice experiencing either muscle disuse or cancer cachexia and further evidenced to contribute to muscle deterioration by enhancing ubiquitin proteolysis; however, to our knowledge, ERG1A has not been reported in human skeletal muscle.
Methods And Results: Here, using immunohistochemistry, we detect ERG1A immunofluorescence in human skeletal muscle sarcolemma. Further, using single point brightness data, we report the detection of ERG1A immunofluorescence at low levels in the muscle sarcolemma of young adult humans and show that it trends toward greater levels (10.
Skeletal muscle atrophy may occur with disease, injury, decreased muscle use, starvation, and normal aging. No reliably effective treatments for atrophy are available, thus research into the mechanisms contributing to muscle loss is essential. The ERG1A K+ channel contributes to muscle loss by increasing ubiquitin proteasome proteolysis (UPP) in the skeletal muscle of both unweighted and cachectic mice.
View Article and Find Full Text PDFBackground: Skeletal muscle atrophy is the net loss of muscle mass that results from an imbalance in protein synthesis and protein degradation. It occurs in response to several stimuli including disease, injury, starvation, and normal aging. Currently, there is no truly effective pharmacological therapy for atrophy; therefore, exploration of the mechanisms contributing to atrophy is essential because it will eventually lead to discovery of an effective therapeutic target.
View Article and Find Full Text PDFThe ERG1A K channel, which is partially responsible for repolarization of the cardiac action potential, has also been reported in skeletal muscle where it modulates ubiquitin proteolysis. Because ERG1A protein appears variably expressed in muscles composed of mixed fiber types, we hypothesized that its abundance in skeletal muscle might differ with fiber type. Indeed, skeletal muscle fibers vary in speed of contraction (fast or slow), which is mainly determined by myosin heavy chain (MyHC) isoform content, but a sarcolemmal K channel might also modulate contraction speed.
View Article and Find Full Text PDFSkeletal muscle (SKM) atrophy is a potentially debilitating condition induced by muscle disuse, denervation, many disease states, and aging. The ubiquitin proteasome pathway (UPP) contributes greatly to the protein loss suffered in muscle atrophy. The MERG1a K(+) channel is known to induce UPP activity and atrophy in SKM.
View Article and Find Full Text PDFIntroduction: We investigated the mechanism by which the MERG1a K+ channel increases ubiquitin proteasome proteolysis (UPP).
Methods: Hindlimb suspension and electro-transfer of Merg1a cDNA into mouse gastrocnemius muscles induced atrophy.
Results: Atrophic gastrocnemius muscles of hindlimb-suspended mice express Merg1a, Murf1, and Mafbx genes.
The Kv11.1 (also ERG1) K(+) channel underlies cardiac I(Kr), a current that contributes to repolarization in mammalian heart. In mice, I(Kr) current density decreases with development and studies suggest that changes in the structure and/or properties of the heteromultimeric I(Kr)/Kv11.
View Article and Find Full Text PDFSkeletal muscle atrophy results from an imbalance in protein degradation and protein synthesis and occurs in response to injury, various disease states, disuse, and normal aging. Current treatments for this debilitating condition are inadequate. More information about mechanisms involved in the onset and progression of muscle atrophy is necessary for development of more effective therapies.
View Article and Find Full Text PDFBackground: Electroporation (EP) is a widely used non-viral gene transfer method. We have attempted to develop an exact protocol to maximize DNA expression while minimizing tissue damage following EP of skeletal muscle in vivo. Specifically, we investigated the effects of varying injection techniques, electrode surface geometry, and plasmid mediums.
View Article and Find Full Text PDFBackground: Mutations in KCNE2 have been linked to long-QT syndrome (LQT6), yet KCNE2 protein expression in the ventricle and its functional role in native channels are not clear.
Methods And Results: We detected KCNE2 protein in human, dog, and rat ventricles in Western blot experiments. Immunocytochemistry confirmed KCNE2 protein expression in ventricular myocytes.
Although electrophysiological remodeling occurs in various myocardial diseases, the underlying molecular mechanisms are poorly understood. cDNA microarrays containing probes for a large population of mouse genes encoding ion channel subunits ("IonChips") were developed and exploited to investigate remodeling of ion channel transcripts associated with altered thyroid status in adult mouse ventricle. Functional consequences of hypo- and hyperthyroidism were evaluated with patch-clamp and ECG recordings.
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