α-Cyclodextrin enhances myoblast fusion and muscle differentiation by the release of IL-4.

Muscle fibers are formed during embryonic development by the fusion of mononucleated myoblasts. The spatial structure and molecular composition of the sarcolemma are crucial for the myoblast recognition and fusion steps. Cyclodextrins are a group of substances that have the ability to solubilize lipids through the formation of molecular inclusion complexes. Previously, we have shown that methyl-β-cyclodextrin (MbCD) enhances muscle differentiation. Here, we analyzed the effects of α-cyclodextrin (aCD) during myogenesis. Myogenic cultures treated with aCD showed an increase in myoblast fusion and in the expression of myogenin, sarcomeric tropomyosin and desmin. aCD-conditioned media accelerates myogenesis in a similar way as aCD does, and increased levels of IL-4 were found in aCD-conditioned media. aCD-induced effects on myogenesis were inhibited by an anti-IL4 antibody. These results show that α-cyclodextrin induces myogenic differentiation by the release of IL-4.