Search results for "Myocyte"
showing 10 items of 248 documents
Human Dental Pulp Stem Cells Improve Left Ventricular Function, Induce Angiogenesis, and Reduce Infarct Size in Rats with Acute Myocardial Infarction
2008
Abstract Human dental pulp contains precursor cells termed dental pulp stem cells (DPSC) that show self-renewal and multilineage differentiation and also secrete multiple proangiogenic and antiapoptotic factors. To examine whether these cells could have therapeutic potential in the repair of myocardial infarction (MI), DPSC were infected with a retrovirus encoding the green fluorescent protein (GFP) and expanded ex vivo. Seven days after induction of myocardial infarction by coronary artery ligation, 1.5 × 106 GFP-DPSC were injected intramyocardially in nude rats. At 4 weeks, cell-treated animals showed an improvement in cardiac function, observed by percentage changes in anterior wall thic…
DNA-fragmentation and apoptosis-related proteins of muscle cells in motor neuron disorders
2009
Apoptosis has been described as one of the mechanisms of muscle fiber loss in infantile spinal muscular atrophy. In order to investigate if muscle fiber-apoptosis plays a role in other denervating disorders as well, we studied DNA-fragmentation, a hallmark of apoptosis, by the TUNEL-method and, moreover, the expression patterns of apoptosis-related proteins in 2 patients suffering from ALS and in 6 patients with polyneuropathy. We identified DNA-cleavage in muscle fibers of all these patients. Furthermore, we found strong expression of bax and ICE promoting apoptosis in muscle fibers. However, also strong expression of the anti-apoptotic factor bcl-2 was found. Our findings indicate that de…
The Disease-Specific Phenotype in Cardiomyocytes Derived from Induced Pluripotent Stem Cells of Two Long QT Syndrome Type 3 Patients
2013
Long QT syndromes (LQTS) are heritable diseases characterized by prolongation of the QT interval on an electrocardiogram, which often leads to syncope and sudden cardiac death. Here we report the generation of induced pluripotent stems (iPS) cells from two patients with LQTS type 3 carrying a different point mutation in a sodium channel Nav1.5 (p.V240M and p.R535Q) and functional characterization of cardiomyocytes (CM) derived from them. The iPS cells exhibited all characteristic properties of pluripotent stem cells, maintained the disease-specific mutation and readily differentiated to CM. The duration of action potentials at 50% and 90% repolarization was longer in LQTS-3 CM as compared t…
Apoptosis-related Proteins in Skeletal Muscle Fibers of Spinal Muscular Atrophy
1997
There is evidence that apoptosis in spinal muscular atrophies (SMA) is not restricted to motor neurons but also affects muscle fibers. Studying the expression of several apoptosis-associated proteins we found constant expression of bax in muscle fibers, which promoted cell death. The expression of bax correlated with defective innervation of muscle fibers was also indicated by upregulation of N-CAM. While in early-onset SMA atrophic as well as normo- and hypertrophic muscle fibers displayed expression of bax, muscle fibers in late-onset SMA and peripheral neuropathies showed bax-expression only in atrophic fibers. Other investigated apoptosis-associated factors comprised interleukin-1 beta …
Type 1 Muscle Fiber Hypertrophy after Blood Flow–restricted Training in Powerlifters
2018
PURPOSE: To investigate the effects of blood flow restricted resistance exercise (BFRRE) on myofiber areas (MFA), number of myonuclei and satellite cells (SC), muscle size and strength in powerlifters. METHODS Seventeen national level powerlifters (25+/-6 yrs [mean+/-SD], 15 men) were randomly assigned to either a BFRRE group (n=9) performing two blocks (week 1 and 3) of five BFRRE front squat sessions within a 6.5-week training period, or a conventional training group (Con; n=8) performing front squats at ~70% of one-repetition maximum (1RM). The BFRRE consisted of four sets (first and last set to voluntary failure) at ~30% of 1RM. Muscle biopsies were obtained from m. vastus lateralis (VL…
Immunolocalization of Tenascin-C in Human Type II Fiber Atrophy
2000
Tenascin-C is a multifunctional extracellular matrix glycoprotein with stimulatory and anti-adhesive or inhibitory properties for axon growth. Its location and discontinuous expression are restricted in innervated muscle tissues. Tenascin-C accumulated interstitially among human denervated muscle fibers and close to normal-sized fibers. To expand our knowledge of the expression of tenascin-C in human neuromuscular disorders, we investigated immunohistologically 20 human muscle specimens with type II myofiber atrophy of children and adults. Tenascin-C immunoreactivity in adult type II atrophy was frequent, and accumulation in children was sparse and weak. In both groups, tenascin-C immunorea…
Delayed myonuclear addition, myofiber hypertrophy, and increases in strength with high-frequency low-load blood flow restricted training to volitiona…
2018
The purpose of the present study was to investigate muscle hypertrophy, strength, and myonuclear and satellite cell (SC) responses to high-frequency blood flow-restricted resistance exercise (BFRRE). Thirteen individuals [24 ± 2 yr (mean ± SD), 9 men] completed two 5-day blocks of 7 BFRRE sessions, separated by a 10-day rest period. Four sets of unilateral knee extensions to voluntary failure at 20% of one repetition maximum (1RM) were conducted with partial blood flow restriction (90–100 mmHg). Muscle samples obtained before, during, 3 days, and 10 days after training were analyzed for muscle fiber area (MFA), myonuclei, SC, and mRNA and miRNA expression. Muscle size was measured by ultra…
Immunohistochemical characterization of endometriosis-associated smooth muscle cells in human peritoneal endometriotic lesions
2011
Background Smooth muscle cells (SMC) are common components of endometriotic lesions. SMC have been characterized previously in peritoneal, ovarian and deep infiltrating endometriotic lesions and adenomyosis. The aim of this retrospective study was to investigate the extent of differentiation in endometriosis-associated SMC (EMaSMC) in peritoneal endometriotic lesions. Methods We obtained biopsies from peritoneal endometriotic lesions (n = 60) and peritoneal sites distant from the endometriotic lesion (n = 60), as well as healthy peritoneum from patients without endometriosis (control tissue, n = 10). These controls were hysterectomy specimens from patients without endometriosis or adenomyos…
Inducible nitric oxide synthase in skeletal muscle of patients with chronic heart failure
1998
Abstract Objectives. The expression and localization of inducible nitric oxide (NO) synthase (NOS II) was evaluated as a source of NO which has been shown to affect muscle contraction. Background. Advanced stages of chronic heart failure are associated with systemic activation of cytokines which have been shown to stimulate the expression of NOS II in various cell types, including myocytes. We hypothesized that systemic cytokine activation could lead to expression of NOS II in skeletal muscle of patients with chronic heart failure. Methods. Skeletal muscle specimens were obtained by percutaneous needle biopsy in six normal volunteers and eight patients with heart failure (New York Heart Ass…
HSF1-controlled and age-associated chaperone capacity in neurons and muscle cells of C. elegans.
2010
Protein stability under changing conditions is of vital importance for the cell and under the control of a fine-tuned network of molecular chaperones. Aging and age-related neurodegenerative diseases are directly associated with enhanced protein instability. Employing C. elegans expressing GFP-tagged luciferase as a reporter for evaluation of protein stability we show that the chaperoning strategy of body wall muscle cells and neurons is significantly different and that both are differently affected by aging. Muscle cells of young worms are largely resistant to heat stress, which is directly mediated by the stress response controlled through Heat Shock Transcription Factor 1. During recover…