1,720,966 research outputs found
Macrophages regulate proliferation and differentiation of satellite cells
No full textBiochem Biophys Res Commun. 1994 Aug 15;202(3):1688-96.
Macrophages regulate proliferation and differentiation of satellite cells.
Cantini M, Massimino ML, Bruson A, Catani C, Dalla Libera L, Carraro U.
Source
Department of Biomedical Sciences, University of Padova, Italy.
Abstract
We used an in vitro model to investigate whether macrophages stimulate satellite cells proliferation. Satellite cells were obtained by tryptic digestion of adult muscle. Macrophages were obtained from peritoneal cavity by wash after injection of thioglycolate broth. Macrophages and satellite cells cocultures showed an increased number of differentiated myotubes as compared to control cultures. Moreover, in conditions of myoblast colony growth, the addition of macrophage-conditioned medium resulted in a greater number of muscle cell colonies, which are richer in large and differentiated myotubes. The experiments with macrophage-conditioned media suggest that the increased muscle cell proliferation and differentiation is mediated by soluble factor(s) released by macrophages. These results demonstrate that besides their scavenger role macrophages play a pivotal role in myoblast proliferation during muscle regeneration.
PMID:
8060358
[PubMed - indexed for MEDLINE
GENE-TRANSFER INTO SATELLITE CELL FROM REGENERATING MUSCLE - BUPIVACAINE ALLOWS BETA-GAL TRANSFECTION AND EXPRESSION IN-VITRO AND IN-VIVO
No full textIn Vitro Cell Dev Biol Anim. 1994 Feb;30A(2):131-3.
Gene transfer into satellite cell from regenerating muscle: bupivacaine allows beta-Gal transfection and expression in vitro and in vivo.
Cantini M, Massimino ML, Catani C, Rizzuto R, Brini M, Carraro U.
Source
Department of Experimental Biomedical Sciences, University of Padua, Italy.
Abstract
A large bulk of experimental evidence (15) suggests that myogenic cell transfer can be regarded as a promising therapeutic approach in the cure of inherited pathologies. In particular, it has been shown that primary myoblasts obtained from embryonic or neonatal muscles allows the recovery of the normal phenotype in defective muscle tissues. The utilization of this approach in clinical settings still bears heavy limitations. Apart from the legal and ethical difficulties, the use of muscles obtained from aborted fetus is challenged by a large risk of rejection, due to the incompatibility between donor and recipient. In this context based on the genetic alteration and reimplanting of the patient's own satellite cells, appears an approach attractive. Myoblasts derived from satellite cells are the obligate candidates for experiments, but the production of sufficient cell numbers is a major problem. Local anesthetics [Bupivacaine (1-n-butyl-DL-piperidine-2-carboxylic acid-2, 6-dimethyl anilide hydrochloride) and related molecules] had been used to induce myofiber damage (and thus satellite cells proliferation) and thereby may represent a tool for increasing the yield of myoblasts from adult muscles (1,9,17). We will show that satellite cells obtained from adult muscles after bupivacaine injection can be transfected in vitro and that the transfected gene is expressed in vitro and in vivo, after reimplantation of the modified myoblasts in recipient muscles.
PMID:
8012655
[PubMed - indexed for MEDLINE
Essential Oil Molecules Can Break the Loop of Oxidative Stress in Neurodegenerative Diseases.
No full textEssential oils (EOs) are mixtures of volatile compounds, extracted from aromatic plants, with multiple activities including antioxidant and anti-inflammatory ones. EOs are complex mixtures easy to find on the market and with low costs. In this mini narrative review, we have collected the results of in vitro and in vivo studies, which tested these EOs on validated models of neurodegeneration and in particular of the two main neurodegenerative diseases (NDs) that afflict humans: Alzheimer’s and Parkinson’s. Since EO compositions can vary greatly, depending on the environmental conditions, plant cultivar, and extraction methods, we focused our attention to studies involving single EO molecules, and in particular those that have demonstrated the ability to cross the blood–brain barrier. These single EO molecules, alone or in defined mixtures, could be interesting new therapies to prevent or slow down oxidative and inflammatory processes which are common mechanisms that contribute to neuronal death in all NDs
Effects of beta 1-integrin antisense phosphorothioate-modified oligonucleotide on myoblast behaviour in vitro.
No full textCell Biochem Funct. 1995 Jun;13(2):99-104.
Effects of beta 1-integrin antisense phosphorothioate-modified oligonucleotide on myoblast behaviour in vitro.
Carraro U, Bruson A, Catani C, Dalla Libera L, Massimino ML, Rizzi C, Rossini K, Sandri M, Cantini M.
Source
University of Padova, CNR Unit for Muscle Biology and Physiopathology, Department of Biomedical Sciences, Italy.
Abstract
Myoblasts gene-engineered in vitro and then injected in vivo are safe, efficient options for gene therapy. While isolation of satellite cells is routinely achieved, their proliferation potential in vitro remains a limiting factor for cell transplantation under clinical conditions. We have studied the role of reversible inhibition of gene expression by antisense oligonucleotides on the proliferation of the myogenic cells. Addition of antisense oligonucleotides to myoblast cultures has been used to inhibit specifically the expression of the beta 1-integrin subunit gene. Here we show that the effects of multiple pulses of a phosphorothioate oligodeoxinucleotide antisense on the attachment to substrata and on the proliferation of myoblasts are dose-dependent. The addition of antisense to rat myoblasts caused rounding up of the cells and most of the cells became detached after several days in culture. A single pulse did not show any consistent effect, while in the presence of continuously administered antisense, the relative numbers of myoblasts in the treated muscle culture increased. We have no evidence of inhibition of myoblast fusion under these conditions. On the other hand, [3H]-TdR incorporation, total DNA and total number of cells decreased in antisense-treated cultures thus demonstrating an inhibitory effect of the phosphorothioate oligonucleotides on DNA synthesis. These side-effects could be overcome by substituting the phosphorothioate by unmodified oligonucleotides, so decreasing the half-life of the antisense, but also its toxicity. The overall results suggest a potential role of integrin antisense strategy in modulating the potential of myoblasts to proliferate.
PMID:
7538914
[PubMed - indexed for MEDLINE
Extracellular copper ions regulate cellular prion protein (PrPC) expression and metabolism in neuronal cells.
No full text[ARTICOLO
ED2+ macrophages increase selectively myoblast proliferation in muscle cultures.
No full textWe have previously shown by coculturing myoblasts and macrophages that myotube formation is strongly increased in vitro by the presence of an acid stable, heat-labile, soluble growth factor(s) secreted by macrophages. In this paper we obtained macrophages from peritoneal washing which also contained limited amounts of other cells such as lymphocytes and mesothelial cells. We here demonstrate that an ED2-positive (ED2+) macrophage subpopulation is responsible for myoblast enhanced proliferation. ED2+ macrophages were separated by a magnetic-activated cell sorter (MACS) using a monoclonal antibody against ED2, a membrane antigen peculiar to macrophages. Both ED2+ macrophages and their conditioned medium increased myotube formation when added to primary muscle cultures. Furthermore we demonstrate that muscle growth induced by macrophages is mainly the consequence of an increased myoblast proliferation by showing the presence of an increased number of MyoD-positive (MyoD+) myonuclei
Dystrophin deficient myotubes undergo apoptosis in mouse primary muscle cell culture after DNA damage.
No full textApoptosis has been demonstrated to occur in differentiated myocardial muscle, neonatal skeletal muscle and skeletal myoblasts in response to injury. In this report, we studied differentiated normal and dystrophin deficient murine skeletal muscle cell cultures that have been injured by a pulse of cis-platinum (2 h). Forty-eight hours after DNA damage, dystrophin positive myotubes appeared almost normal though some myoblasts showed DNA fragmentation. On the other hand, dystrophin deficient myotubes presented progressive degeneration via apoptosis detected either by TUNEL or by nuclear morphology. Degeneration of mdx muscle fibers was confirmed by counting both the number of myotubes observed by contrast phase microscopy and myonuclei viewed by immunoreaction for MyoD. A 6-fold decrease in the number of muscle cells was observed in the dystrophin-deficient cell culture compared to the parental culture (P < 0.001). Direct evidence of degenerating myotubes displaying MyoD- and TUNEL-positiv..
Subcellular analysis of Ca2+ homeostasis in primary cultures of skeletal muscle myotubes
No full textSpecifically targeted aequorin chimeras were used for studying the dynamic changes of Ca2+ concentration in different subcellular compartments of differentiated skeletal muscle myotubes. For the cytosol, mitochondria, and nucleus, the previously described chimeric aequorins were utilized; for the sarcoplasmic reticulum (SR), a new chimera (srAEQ) was developed by fusing an aequorin mutant with low Ca2+ affinity to the resident protein calsequestrin. By using an appropriate transfection procedure, the expression of the recombinant proteins was restricted, within the culture, to the differentiated myotubes, and the correct sorting of the various chimeras was verified with immunocytochemical techniques. Single-cell analysis of cytosolic Ca2+ concentration ([Ca2+](c)) with fura-2 showed that the myotubes responded, as predicted, to stimuli known to be characteristic of skeletal muscle fibers, i.e., KCl-induced depolarization, caffeine, and carbamylcholine. Using these stimuli in cultures transfected with the various aequorin chimeras, we show that: 1) the nucleoplasmic Ca2+ concentration ([Ca2+](n)) closely mimics the [Ca2+](c), at rest and after stimulation, indicating a rapid equilibration of the two compartments also in this cell type; 2) on the contrary, mitochondria amplify 4-6-fold the [Ca2+](c) increases; and 3) the lumenal concentration of Ca2+ within the SR ([Ca2+](sr)) is much higher than in the other compartments (>100 mu M), too high to be accurately measured also with the aequorin mutant with low Ca2+ affinity. An indirect estimate of the resting value (similar to 1-2 mM) was obtained using Sr2+, a surrogate of Ca2+ which, because of the lower affinity of the photoprotein for this cation, elicits a lower rate of aequorin consumption. With Sr2+, the kinetics and amplitudes of the changes in [cation(2+)](sr) evoked by the various stimuli could also be directly analyzed.
Accession Number: WOS:A1997WE5410001
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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