Related Experiment Video
Updated: Aug 24, 2026
CRISPR/Cas9 Technology in Restoring Dystrophin Expression in iPSC-Derived Muscle Progenitors
Published on: September 14, 2019
Cloning of cDNA encoding a regeneration-associated muscle protease whose expression is attenuated in cell lines
Yuki Nakayama1, Noriko Nara, Yukiko Kawakita
1Department of Tumor Biochemistry, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan..
Abstract:
In the dystrophin-mutant mdx mouse, an animal model for Duchenne muscular dystrophy (DMD), damaged skeletal muscles are efficiently regenerated and thus the animals thrive. The phenotypic differences between DMD patients and the mdx mice suggest the existence of factors that modulate the muscle wasting in the mdx mice. To identify these factors, we searched for mRNAs affected by the mdx mutation by using cDNA microarrays with newly established skeletal muscle cell lines from mdx and normal mice. We found that in the mdx muscle cell line, 12 genes, including L-arginine:glycine amidinotransferase and thymosin beta4, are up-regulated, whereas 7 genes, including selenoprotein P and a novel regeneration-associated muscle protease (RAMP), are down-regulated. Northern blot analysis and in situ hybridization revealed that RAMP mRNA is predominantly expressed in normal skeletal muscle and brain, and its production is enhanced in the regenerating area of injured skeletal muscle in mice. RAMP expression was much lower in individual muscle cell lines derived from biopsies of six DMD patients compared to a normal muscle cell line. These results suggest that RAMP may play a role in the regeneration of skeletal muscle and that its down-regulation could be involved in the progression of DMD in humans.
Insights
Researchers identified key gene expression differences between mdx mice and Duchenne muscular dystrophy (DMD) patients. A novel protein, RAMP, was found to be downregulated in DMD patients, suggesting a role in skeletal muscle regeneration.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Duchenne muscular dystrophy (DMD) is characterized by muscle wasting.
- The mdx mouse model shows efficient muscle regeneration, unlike DMD patients.
- This difference suggests modulating factors are present in mdx mice.
Purpose of the Study:
- To identify genes and factors that differ between mdx mice and DMD patients.
- To investigate the role of these factors in skeletal muscle regeneration and disease progression.
Main Methods:
- Utilized cDNA microarrays to compare gene expression in mdx and normal mouse skeletal muscle cell lines.
- Employed Northern blot analysis and in situ hybridization to study RAMP mRNA expression.
- Analyzed RAMP expression in muscle cell lines from DMD patients.
Main Results:
- Identified 12 upregulated and 7 downregulated genes in mdx muscle cell lines.
- Discovered that regeneration-associated muscle protease (RAMP) mRNA is downregulated in mdx mice.
- RAMP is predominantly expressed in normal skeletal muscle and brain, and its expression increases during muscle regeneration.
- RAMP expression was significantly lower in muscle cell lines from DMD patients compared to normal controls.
Conclusions:
- RAMP may play a crucial role in skeletal muscle regeneration.
- Downregulation of RAMP could be implicated in the progression of Duchenne muscular dystrophy in humans.
More Related Videos
10:28Direct Reprogramming of Human Fibroblasts into Myoblasts to Investigate Therapies for Neuromuscular Disorders
Published on: April 3, 2021
09:11Generation of Induced Pluripotent Stem Cells from Muscular Dystrophy Patients: Efficient Integration-free Reprogramming of Urine Derived Cells
Published on: January 28, 2015
Related Concept Videos
01:21Satellite Stem Cells and Muscular Dystrophy
02:23Master Transcription Regulators