Muscle cell surface glycans and receptors

Muscle cell surface glycans and receptors constitute the molecular interface of the sarcolemmal membrane, mediating the interaction between muscle fibers and their environment. This category includes a variety of glycoproteins, such as the dystrophin-associated glycoprotein complex (DAGC), and signaling receptors like the transferrin receptor 1 (TfR1) and insulin-like growth factor 1 receptor (IGF-1R). Glycans, including heparan sulfate, sialic acid, and galactose, are critical for the initial attachment of therapeutic agents, particularly adeno-associated virus (AAV) vectors, which then utilize specific protein co-receptors for cellular entry. In modern pharmacology, these surface molecules are primarily targeted for the delivery of advanced therapeutics. For example, antibody-oligonucleotide conjugates (AOCs) and Fab-based platforms exploit the high expression of TfR1 on skeletal and cardiac muscle to deliver RNA-based drugs for conditions like myotonic dystrophy and Duchenne muscular dystrophy. Additionally, defects in the glycosylation of these surface molecules, such as the hyposialylation seen in GNE myopathy or the loss of O-mannosyl glycans on alpha-dystroglycan in dystroglycanopathies, are direct drivers of disease. Consequently, these molecules serve as both essential vehicles for drug delivery and critical targets for structural or functional restoration.

Other names

Muscle cell surface markersSarcolemmal receptorsMuscle glycocalyxDystrophin-associated glycoprotein complex componentsMuscle-specific receptors

Drugs targeting these molecules typically utilize receptor-mediated endocytosis for tissue-specific delivery, exploit glycan-binding for viral vector attachment and entry, or aim to restore defective glycosylation patterns to maintain muscle structural integrity.