Optimizing Immunohistochemical Detection of Matriglycan in Muscles of Dystroglycanopathy.

Detection of matriglycan on α-dystroglycan by immunohistochemistry is one of the essential approaches for studying the mechanisms of functional glycosylation of α-DG, the pathogenesis of dystroglycanopathy, and developing experimental therapies. The limited source of matriglycan-specific antibodies of mouse origin, and their low affinity, pose significant difficulty for evaluating the levels and distribution of matriglycan expression, particularly in diseased mouse models. This study describes an optimized procedure with single ethanol fixation of cryosections that creates the strongest and most consistent membrane signal for matriglycan with the IIH6 C4 antibody. This, together with a reduction in background staining, results in optimal contrast between matriglycan signals and background staining in dystrophic muscle tissues. This procedure increases sensitivity for detecting lower levels of matriglycan in situ, in mouse models, and in human muscle. The optimized method is therefore valuable for evaluating experimental therapies preclinically and in clinical trials for all dystroglycanopathies.