Myogenic induction of adult and pluripotent stem cells using recombinant proteins

Met Activating Genetically Improved Chimeric Factor 1 (Magic-F1) is a human recombinant protein, derived from dimerization of the receptor-binding domain of hepatocyte growth factor. Previous experiments demonstrate that in transgenic mice, the skeletal muscle specific expression of Magic-F1 can induce a constitutive muscular hypertrophy, improving running performance and accelerating muscle regeneration after injury. In order to evaluate the therapeutic potential of Magic-F1, we tested its effect on multipotent and pluripotent stem cells. In murine mesoangioblasts (adult vessel-associated stem cells), the presence of Magic-F1 did not alter their osteogenic, adipogenic or smooth muscle differentiation ability. However, when analyzing their myogenic potential, mesoangioblasts expressing Magic-F1 differentiated spontaneously into myotubes. Finally, Magic-F1 inducible cassette was inserted into a murine embryonic stem cell line by homologous recombination. When embryonic stem cells were subjected to myogenic differentiation, the presence of Magic-F1 resulted in the upregulation of Pax3 and Pax7 that enhanced the myogenic commitment of transgenic pluripotent stem cells. Taken together our results candidate Magic-F1 as a potent myogenic stimulator, able to enhance muscular differentiation from both adult and pluripotent stem cells. publisher: Elsevier articletitle: Myogenic induction of adult and pluripotent stem cells using recombinant proteins journaltitle: Biochemical and Biophysical Research Communications articlelink: http://dx.doi.org/10.1016/j.bbrc.2015.07.022 content_type: article copyright: Copyright © 2015 The Authors. Published by Elsevier Inc. ispartof: Biochemical and Biophysical Research Communications vol:464 issue:3 pages:755-61 ispartof: location:United States status: publishe

Analysis of isometric strength and force-velocity relationship after 7 weeks of stable and unstable training on partial push up

Training with instability device seems to have useful adaptaments, but not all the autor confirm it. Instability training shows increase muscle activation due to the needed for stabilization. The increased stress associated with instability training has been postulated to promote greater neuromuscular adaptations, such as decreased co-contractions, improved intra and inter-coordination and set a lower stress on joint and muscle that can beneficial for musculoskeletal healt and rehabilitation. The aim of the research was to find the difference related in strength gain between an exercise under stable and unstable condition. Two groups of healty-fitness people follow a 7 weeks of stable and unstable training on partial push-up. The control group (CG) (n = 4, one female and three males, 25.0 ± 3.9 y) performed the push-up with hands on the floor, while the sperimental group (SG) (n = 7, two females and five males, 24.6 ± 2.3 y) performed push-up with hands on a Swissball. The execution time, the total volume and the articular ROM were standardized. The tests were: (1) a standardized isometric chest press and (2) force-velocity relationship of the chest muscle. For statistical analysis has been used the Wilcoxon matched-pairs signed rank test. The isometric strength has a positive correlation with the instability training (p 0.05). Instability training seems to show best adaptations on isometric strength, probably due to neural adaptations, while it seems that it doesn’t happen in force-velocity relationship, probably due to the standardized time of execution

Localization of Magic-F1 Transgene, Involved in Muscular Hypertrophy, during Early Myogenesis

We recently showed that Magic-F1 (Met-activating genetically improved chimeric factor 1), a human recombinant protein derived from hepatocyte growth factor/scatter factor (HGF/SF) induces muscle cell hypertrophy but not progenitor cell proliferation, both in vitro and in vivo. Here, we examined the temporal and spatial expression pattern of Magic-F1 in comparison with Pax3 (paired box gene 3) transcription factor during embryogenesis. Ranging from 9.5 to 17.5 dpc (days post coitum) mouse embryos were analyzed by in situ hybridization using whole mounts during early stages of development (9.5–10.5–11.5 dpc) and cryostat sections for later stages (11.5–13.5–15.5–17.5 dpc). We found that Magic-F1 is expressed in developing organs and tissues of mesenchymal origin, where Pax3 signal appears to be downregulated respect to the wt embryos. These data suggest that Magic-F1 could be responsible of muscular hypertrophy, cooperating with Pax3 signal pathway in skeletal muscle precursor cells

Muscle hypertrophy and vascularization induction using human recombinant proteins

Met-Activating Genetically Improved Chimeric Factor-1 (Magic-F1) is an engineered protein that contains two human Met-binding domains. Previous experiments in both homozygous and hemizygous transgenic mice demonstrated that the skeletal muscle specific expression of Magic-F1 can induce a constitutive muscular hypertrophy, increasing the vessel number in fast twitch fibers, also improving running performance and accelerating muscle regeneration after injury [1]. We also found that Magic-F1 could be responsible of muscular hypertrophy inteacting with Pax3 signal pathway in skeletal muscle precursor cells [2]. In order to evaluate the therapeutic potential of Magic-F1, we tested its effect on multipotent and pluripotent stem cells [3]. Murine mesoangioblasts (adult vessel-associated stem cells) expressing Magic-F1 were able to differentiate spontaneously forming myotubes. In addition, in Magic-F1 inducible murine embryonic stem cells subjected to myogenic differentiation, the presence of recombinant protein resulted in improved myogenic commitment. Finally, the microarray analysis of Magic-F1+/+ satellite cells evidenced transcriptomic changes in genes involved in the control of muscle growth, development and vascularisation [4]. Taken together our results candidate Magic-F1 as a potent myogenic inducer, able to affect positively the vascular network, increasing vessel number in fast twitch fibers and modulating the gene expression profile in myogenic progenitors

Magic-F1 transgene cooperates with Pax 3 during early myogenesis to induce muscular hypertrophy

Met-Activating Genetically Improved Chimeric Factor-1 (Magic-F1) is a human recombinant protein derived from hepatocyte growth factor/scatter factor (HGF/ SF) and consists in two Met-binding domains repeated in tandem and separated by an artificial linker. It has a reduced affinity for Met and, in contrast to HGF, it elicits activation of the AKT but not the ERK signaling pathway. We recently showed that Magic-F1 induces muscle cell hypertrophy but not progenitor cell proliferation, both in vitro and in vivo where a transgenic mouse express the recombinant protein exclusively in skeletal muscle tissue [1]. Here, we examined the temporal and spatial expression pattern of Magic-F1 in comparison with Pax3 (paired box gene 3) transcription factor during embryogenesis [2]. Ranging from 9.5 to 17.5 dpc (days post coitum) mouse embryos were analyzed by in situ hybridization using whole mounts during early stages of development (9.5-10.5-11.5 dpc) and cryostat sections for later stages (11.5-13.5-15.5-17.5 dpc). We found that Magic-F1 is expressed in developing organs and tissues of mesenchymal origin, where Pax3 signal appears to be downregulated respect to the wt embryos. These data suggest that Magic-F1 could be responsible of muscular hypertrophy, cooperating with Pax3 signal pathway in skeletal muscle precursor cells

Guide cells support muscle regeneration and affect neuro-muscular junction organization

Muscular regeneration is a complex biological process that occurs during acute injury and chronic degeneration, implicating several cell types. One of the earliest events of muscle regeneration is the inflammatory response, followed by the activation and differentiation of muscle progenitor cells. However, the process of novel neuromuscular junction formation during muscle regeneration is still largely unexplored. Here, we identify by single-cell RNA sequencing and isolate a subset of vessel-associated cells able to improve myogenic differentiation. We termed them 'guide' cells because of their remarkable ability to improve myogenesis without fusing with the newly formed fibers. In vitro, these cells showed a marked mobility and ability to contact the forming myotubes. We found that these cells are characterized by CD44 and CD34 surface markers and the expression of Ng2 and Ncam2. In addition, in a murine model of acute muscle injury and regeneration, injection of guide cells correlated with increased numbers of newly formed neuromuscular junctions. Thus, we propose that guide cells modulate de novo generation of neuromuscular junctions in regenerating myofibers. Further studies are necessary to investigate the origin of those cells and the extent to which they are required for terminal specification of regenerating myofibers

Comparative analysis of different hydrogels for the bioprinting of 3D in vitro skeletal muscle models

In this study we demonstrated an application of 3D Bioprinting using different commercially available hydrogels (CELLINK AB, Sweden) with the aim to identify the most suitable biomaterial for the proliferation and differentiation of murine muscle cells (C2C12)

Localization of Magic-F1 Transgene, Involved in Muscular Hypertrophy, during Early Myogenesis

We recently showed that Magic-F1 (Met-activating genetically improved chimeric factor 1), a human recombinant protein derived from hepatocyte growth factor/scatter factor (HGF/SF) induces muscle cell hypertrophy but not progenitor cell proliferation, both in vitro and in vivo. Here, we examined the temporal and spatial expression pattern of Magic-F1 in comparison with Pax3 (paired box gene 3) transcription factor during embryogenesis. Ranging from 9.5 to 17.5 dpc (days post coitum) mouse embryos were analyzed by in situ hybridization using whole mounts during early stages of development (9.5-10.5-11.5 dpc) and cryostat sections for later stages (11.5-13.5-15.5-17.5 dpc). We found that Magic-F1 is expressed in developing organs and tissues of mesenchymal origin, where Pax3 signal appears to be downregulated respect to the wt embryos. These data suggest that Magic-F1 could be responsible of muscular hypertrophy, cooperating with Pax3 signal pathway in skeletal muscle precursor cells

miR669a and miR669q prevent skeletal muscle differentiation in postnatal cardiac progenitors

miR669a and miR669q inhibit postnatal cardiac progenitor differentiation by directly targeting the 3′UTR of MyoD