scholarly journals Cellular trafficking determines the exon skipping activity of Pip6a-PMO in mdx skeletal and cardiac muscle cells

2013 ◽  
Vol 42 (5) ◽  
pp. 3207-3217 ◽  
Author(s):  
Taavi Lehto ◽  
Alejandra Castillo Alvarez ◽  
Sarah Gauck ◽  
Michael J. Gait ◽  
Thibault Coursindel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Biological Activity ◽  
Exon Skipping ◽  
Muscle Cells ◽  
Mechanistic Explanation ◽  
Endosomal Escape ◽  
Skeletal Muscle Cells ◽  
Great Promise ◽  
Cellular Trafficking ◽  
Cardiac Muscle Cells

Abstract Cell-penetrating peptide-mediated delivery of phosphorodiamidate morpholino oligomers (PMOs) has shown great promise for exon-skipping therapy of Duchenne Muscular Dystrophy (DMD). Pip6a-PMO, a recently developed conjugate, is particularly efficient in a murine DMD model, although mechanisms responsible for its increased biological activity have not been studied. Here, we evaluate the cellular trafficking and the biological activity of Pip6a-PMO in skeletal muscle cells and primary cardiomyocytes. Our results indicate that Pip6a-PMO is taken up in the skeletal muscle cells by an energy- and caveolae-mediated endocytosis. Interestingly, its cellular distribution is different in undifferentiated and differentiated skeletal muscle cells (vesicular versus nuclear). Likewise, Pip6a-PMO mainly accumulates in cytoplasmic vesicles in primary cardiomyocytes, in which clathrin-mediated endocytosis seems to be the pre-dominant uptake pathway. These differences in cellular trafficking correspond well with the exon-skipping data, with higher activity in myotubes than in myoblasts or cardiomyocytes. These differences in cellular trafficking thus provide a possible mechanistic explanation for the variations in exon-skipping activity and restoration of dystrophin protein in heart muscle compared with skeletal muscle tissues in DMD models. Overall, Pip6a-PMO appears as the most efficient conjugate to date (low nanomolar EC50), even if limitations remain from endosomal escape.

scholarly journals Proto-oncogene expression in proliferating and differentiating cardiac and skeletal muscle

1987 ◽  
Vol 247 (3) ◽  
pp. 701-706 ◽  
Author(s):  
W C Claycomb ◽  
N A Lanson
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Muscle Tissue ◽  
Cellular Proliferation ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Specific Cell ◽  
Adult Rats ◽  
Cardiac Muscle Cells ◽  
Oncogene Expression

We have examined the expression of 13 proto-oncogenes in proliferating and terminally differentiated cardiac and skeletal muscle. Total RNA was prepared from intact ventricular cardiac-muscle tissue and from purified ventricular cardiac-muscle cells of neonatal and adult rats and from cultured proliferating and terminally differentiated L6A1 rat skeletal-muscle cells. cDNA probes for histone H4, thymidine kinase, myosin heavy chain and M-creatine kinase were used to assess cellular proliferation and differentiation. Oncogenes c-myc, c-raf, c-erb-A, c-ras-H, c-ski, and c-sis were expressed in both proliferating and differentiated cardiac muscle tissue and cells, whereas c-myb expression was not observed in either. c-src was expressed only in neonatal cardiac muscle tissue and cells. c-fms, c-abl, and c-ras-K were expressed in tissue from both neonatal and adult animals but only in purified cells from neonatal animals. c-fes/fps was expressed only in neonatal cardiac muscles cells. c-fos expression was not observed in cardiac-muscle tissue from either neonatal or adult rats, but surprisingly was abundantly expressed in freshly isolated cardiac-muscle cells from animals of both ages. These results emphasize that biochemical analysis using intact cardiac-muscle tissue may not necessarily reflect muscle-specific cell processes. They also show that the expression of c-fos can be activated by the cell isolation procedure. c-myc, c-ski, c-ras-H, c-ras-K, c-abl, c-raf and c-erb-A were expressed in both proliferating and terminally differentiated skeletal-muscle cells, whereas c-myb, c-fos, c-src and c-fms transcripts were observed only in proliferating cells. c-fes/fps and c-sis were not expressed in dividing or fused skeletal-muscle cells. These results demonstrate unique tissue and cell-specific patterns of proto-oncogene expression and suggest that these genes may be involved with the regulation of cellular proliferation and terminal differentiation in striated muscle.

Extracts of Hymenocardia acida ameliorate insulin resistance in skeletal muscle cells

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
II Ezeigbo ◽  
C Wheeler-Jones ◽  
S Gibbons ◽  
ME Cleasby
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Ameliorate Insulin Resistance

TGFß regulates metabolism of human skeletal muscle cells by miRNAs

2018 ◽  
Author(s):  
S Höckele ◽  
P Huypens ◽  
C Hoffmann ◽  
T Jeske ◽  
M Hastreiter ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Human Skeletal Muscle Cells

scholarly journals Annexins and Membrane Repair Dysfunctions in Muscular Dystrophies

2021 ◽  
Vol 22 (10) ◽  
pp. 5276
Author(s):  
Coralie Croissant ◽  
Romain Carmeille ◽  
Charlotte Brévart ◽  
Anthony Bouter
Keyword(s):  
Skeletal Muscle ◽  
Muscular Dystrophy ◽  
Genetic Disorders ◽  
Muscle Cells ◽  
Cell Types ◽  
Clinical Severity ◽  
Skeletal Muscle Cells ◽  
Muscular Dystrophies ◽  
Membrane Repair ◽  
Human Skeletal Muscle Cells

Muscular dystrophies constitute a group of genetic disorders that cause weakness and progressive loss of skeletal muscle mass. Among them, Miyoshi muscular dystrophy 1 (MMD1), limb girdle muscular dystrophy type R2 (LGMDR2/2B), and LGMDR12 (2L) are characterized by mutation in gene encoding key membrane-repair protein, which leads to severe dysfunctions in sarcolemma repair. Cell membrane disruption is a physiological event induced by mechanical stress, such as muscle contraction and stretching. Like many eukaryotic cells, muscle fibers possess a protein machinery ensuring fast resealing of damaged plasma membrane. Members of the annexins A (ANXA) family belong to this protein machinery. ANXA are small soluble proteins, twelve in number in humans, which share the property of binding to membranes exposing negatively-charged phospholipids in the presence of calcium (Ca2+). Many ANXA have been reported to participate in membrane repair of varied cell types and species, including human skeletal muscle cells in which they may play a collective role in protection and repair of the sarcolemma. Here, we discuss the participation of ANXA in membrane repair of healthy skeletal muscle cells and how dysregulation of ANXA expression may impact the clinical severity of muscular dystrophies.

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