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Updated: Feb 9, 2026
Direct Reprogramming of Human Fibroblasts into Myoblasts to Investigate Therapies for Neuromuscular Disorders
Published on: April 3, 2021
Beta-2 Adrenergic Receptor Agonists Enhance AChR Clustering in C2C12 Myotubes: Implications for Therapy of Myasthenic
Lisa Clausen1, Judith Cossins1, David Beeson1
1Neurosciences Group, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.
Background:
Congenital myasthenic syndromes (CMS) are a group of inherited neuromuscular transmission disorders causing fatiguable muscle weakness. ADRB2 agonists have been observed to provide therapeutic benefit where destabilisation of NMJ structures is part of the underlying pathology, such as in DOK7, COLQ and MuSK CMS as well as in slow channel syndrome. However, very little is known about the molecular mechanisms underlying the effects of ADRB2 agonists in CMS.
Objective:
In vitro investigation into whether an ADRB2 agonist affects the AChR clustering pathway and has the potential to increase the number and stability of AChR clusters.
Methods:
Cultured C2C12 mouse myotubes overexpressing the common DOK7 frameshift mutation c.1124_1127dupTGCC were incubated with salbutamol sulphate and the effect on AChR cluster numbers were investigated. Moreover, agrin-induced AChR clusters in C2C12 WT cells were left to disperse after agrin-wash-off, and the effects of incubation with salbutamol sulphate on AChR cluster numbers were explored.
Results:
Salbutamol sulphate induced a significant increase in the number of AChR clusters formed on C2C12 cells overexpressing c.1124_1127dupTGCC. Furthermore, significantly more clusters remained in C2C12 WT myotubes incubated with salbutamol sulphate following agrin wash-off.
Conclusions:
The results suggest that ADRB2 agonists directly affect proteins located at the neuromuscular junction and exert a stabilising effect on AChR clusters.
Insights
ADRB2 agonists, like salbutamol sulphate, increase acetylcholine receptor (AChR) clusters in muscle cells. This finding suggests a potential therapeutic strategy for congenital myasthenic syndromes (CMS) by stabilizing neuromuscular junctions.
Area of Science:
- Neuromuscular biology
- Pharmacology
- Genetic disorders
Background:
- Congenital myasthenic syndromes (CMS) are inherited disorders affecting neuromuscular transmission, leading to muscle weakness.
- ADRB2 agonists show promise for CMS with neuromuscular junction (NMJ) destabilization, but their mechanisms are unclear.
Purpose of the Study:
- To investigate if ADRB2 agonists influence acetylcholine receptor (AChR) clustering.
- To determine if ADRB2 agonists can enhance the number and stability of AChR clusters.
Main Methods:
- Utilized cultured C2C12 mouse myotubes with a DOK7 frameshift mutation.
- Assessed salbutamol sulphate's effect on AChR cluster formation and stability after agrin-induced clustering and wash-off.
Main Results:
- Salbutamol sulphate significantly increased AChR cluster numbers in DOK7-mutant myotubes.
- More AChR clusters persisted in wild-type myotubes treated with salbutamol sulphate after agrin removal.
Conclusions:
- ADRB2 agonists directly impact NMJ proteins.
- These agonists stabilize AChR clusters, suggesting a direct therapeutic effect in certain CMS types.
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