Search results for "Myocyte"
showing 10 items of 248 documents
Different modes of activating phosphofructokinase, a key regulatory enzyme of glycolysis, in working vertebrate muscle
2002
Glycolytic flux in white muscle can be increased several-hundredfold by exercise. Phosphofructokinase (PFK; EC 2.7.1.11) is a key, regulatory enzyme of glycolysis, but how its activity in muscle is controlled is not fully, understood. In order not to neglect integrative aspects of metabolic regulation, we have studied in frogs (Rana temporaria) a physiological form of muscle work (swimming) that can be triggered like a reflex. We analysed swimming to fatigue in well rested frogs, recovery from exercise, and repeated exercise after 2 h of recovery. At various times, gastrocnemius muscles were tested for glycolytic intermediates and effectors of PFK. All metabolites responded similarly to the…
Chronically elevated branched chain amino acid levels are pro-arrhythmic.
2022
Aim. Cardiac arrhythmias comprise a major health and economic burden and are associated with significant morbidity and mortality, including cardiac failure, stroke and sudden cardiac death (SCD). Development of efficient preventive and therapeutic strategies is hampered by incomplete knowledge of disease mechanisms and pathways. Our aim is to identify novel mechanisms underlying cardiac arrhythmia and SCD using an unbiased approach. Methods and Results. We employed a phenotype-driven N-ethyl-N-nitrosourea (ENU) mutagenesis screen and identified a mouse line with a high incidence of sudden death at young age (6-9 weeks) in the absence of prior symptoms. Affected mice were found to be homozyg…
Correction: Daunorubicin reduces MBNL1 sequestration caused by CUG-repeat expansion and rescues cardiac dysfunctions in a Drosophila model of myotoni…
2018
ABSTRACT Myotonic dystrophy (DM) is a dominantly inherited neuromuscular disorder caused by expression of mutant myotonin-protein kinase (DMPK) transcripts containing expanded CUG repeats. Pathogenic DMPK RNA sequesters the muscleblind-like (MBNL) proteins, causing alterations in metabolism of various RNAs. Cardiac dysfunction represents the second most common cause of death in DM type 1 (DM1) patients. However, the contribution of MBNL sequestration in DM1 cardiac dysfunction is unclear. We overexpressed Muscleblind (Mbl), the Drosophila MBNL orthologue, in cardiomyocytes of DM1 model flies and observed a rescue of heart dysfunctions, which are characteristic of these model flies and resem…
Discoordinate regulation of different K channels in cultured rat skeletal muscle by nerve growth factor
1999
We investigated the effects of nerve growth factor (NGF) on expression of K+ channels in cultured skeletal muscle. The channels studied were (1) charybdotoxin (ChTx)-sensitive channels by using a polyclonal antibody raised in rabbits against ChTx, (2) Kv1.5 voltage-sensitive channels, and (3) apamin-sensitive (afterhyperpolarization) channels. Crude homogenates were prepared from cultures made from limb muscles of 1-2-day-old rat pups for identification of ChTx-sensitive and Kv1.5 channels by Western blotting techniques. Apamin-sensitive K+ channels were studied by measurement of specific [125I]-apamin binding by whole cell preparations. ChTx-sensitive channels display a fusion-related incr…
Neomyogenesis in 3D Dynamic Responsive Prosthesis for Inguinal Hernia Repair
2018
Despite undisputed improvements, prosthetics hernia repair continues to be affected by unacceptable rates of complications. Postoperative adverse events such as discomfort and chronic pain represent a subject of increasing concern among the surgical community. Poor quality biologic response, stiff scar plates, and mesh shrinkage, a typical effect of conventional static meshes and plugs, are all indicated as the main reasons for many of the complications related to inguinal hernia repair. Even the conventional concept of treatment based upon a supposed reinforcement of the groin consequent to the fibrotic incorporation of meshes, would appear to be inadequate in the light of the latest scien…
HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat card…
2007
Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…
Hormone replacement therapy enhances IGF-1 signaling in skeletal muscle by diminishing miR-182 and miR-223 expressions : a study on postmenopausal mo…
2014
MiRNAs are fine-tuning modifiers of skeletal muscle regulation, but knowledge of their hormonal control is lacking. We used a co-twin case-control study design, that is, monozygotic postmenopausal twin pairs discordant for estrogen-based hormone replacement therapy (HRT) to explore estrogen-dependent skeletal muscle regulation via miRNAs. MiRNA profiles were determined from vastus lateralis muscle of nine healthy 54-62-years-old monozygotic female twin pairs discordant for HRT (median 7 years). MCF-7 cells, human myoblast cultures and mouse muscle experiments were used to confirm estrogen's causal role on the expression of specific miRNAs, their target mRNAs and proteins and finally the act…
Therapeutic targets for overactive bladder other than smooth muscle
2015
For a long time, our concepts of regulation of urinary bladder function in health and disease as well as of the target structures of therapeutics have focused on detrusor smooth muscle cells. However, other structures including urothelium, afferent nerves and bladder blood vessels may also be important in pathophysiology and its treatment.Based on a selective review of literature, we discuss the role of urothelium, afferent nerve fibers and bladder blood vessels in bladder pathophysiology and as targets for treatment.There is solid evidence now that multiple anatomical structures within the urinary bladder contribute to the regulation of its function and hence may be targets for established…
The emerging role of miRNA-132/212 cluster in neurologic and cardiovascular diseases: Neuroprotective role in cells with prolonged longevity
2021
Abstract miRNA-132/212 are small regulators of gene expression with a function that fulfills a vital function in diverse biological processes including neuroprotection of cells with prolonged longevity in neurons and the cardiovascular system. In neurons, miRNA-132 appears to be essential for controlling differentiation, development, and neural functioning. Indeed, it also universally promotes axon evolution, nervous migration, plasticity as well, it is suggested to be neuroprotective against neurodegenerative diseases. Moreover, miRNA-132/212 disorder leads to neural developmental perturbation, and the development of degenerative disorders covering Alzheimer’s, Parkinson’s, and epilepsy’s …
Dose-dependent biphasic leptin-induced proliferation is caused by non-specific IL-6/NF-κB pathway activation in human myometrial cells
2015
Background and Purpose Leptin, an adipokine synthesized by the placenta during pregnancy, has been proposed for the management of preterm labour (PTL), as it is able to prevent in vitro uterine contractility and remodelling associated with labour onset. Another common feature of labour onset is the phenotypic switch of myometrial smooth muscle cells from a proliferative to a hypertrophic state. As proliferative effects have been demonstrated for leptin in other tissues, we aimed to investigate its ability to induce myometrial proliferation and thus to maintain uterine quiescence. Experimental Approach We stimulated human primary myometrial smooth muscle cells with leptin in the presence or …