| First Author | Solares-Pérez A | Year | 2010 |
| Journal | Biochim Biophys Acta | Volume | 1800 |
| Issue | 3 | Pages | 373-9 |
| PubMed ID | 19931597 | Mgi Jnum | J:164821 |
| Mgi Id | MGI:4835364 | Doi | 10.1016/j.bbagen.2009.11.011 |
| Citation | Solares-Perez A, et al. (2010) Intracellular Ca2+ transients in delta-sarcoglycan knockout mouse skeletal muscle. Biochim Biophys Acta 1800(3):373-9 |
| abstractText | BACKGROUND: delta-Sarcoglycan (delta-SG) knockout (KO) mice develop skeletal muscle histopathological alterations similar to those in humans with limb muscular dystrophy. Membrane fragility and increased Ca(2+) permeability have been linked to muscle degeneration. However, little is known about the mechanisms by which genetic defects lead to disease. METHODS: Isolated skeletal muscle fibers of wild-type and delta-SG KO mice were used to investigate whether the absence of delta-SG alters the increase in intracellular Ca(2+) during single twitches and tetani or during repeated stimulation. Immunolabeling, electrical field stimulation and Ca(2+) transient recording techniques with fluorescent indicators were used. RESULTS: Ca(2+) transients during single twitches and tetani generated by muscle fibers of delta-SG KO mice are similar to those of wild-type mice, but their amplitude is greatly decreased during protracted stimulation in KO compared to wild-type fibers. This impairment is independent of extracellular Ca(2+) and is mimicked in wild-type fibers by blocking store-operated calcium channels with 2-aminoethoxydiphenyl borate (2-APB). Also, immunolabeling indicates the localization of a delta-SG isoform in the sarcoplasmic reticulum of the isolated skeletal muscle fibers of wild-type animals, which may be related to the functional differences between wild-type and KO muscles. CONCLUSIONS: delta-SG has a role in calcium homeostasis in skeletal muscle fibers. GENERAL SIGNIFICANCE: These results support a possible role of delta-SG on calcium homeostasis. The alterations caused by the absence of delta-SG may be related to the pathogenesis of muscular dystrophy. |
