Mitochondrial DNA deletions in muscle satellite cells: implications for therapies
نویسندگان
چکیده
Progressive myopathy is a major clinical feature of patients with mitochondrial DNA (mtDNA) disease. There is limited treatment available for these patients although exercise and other approaches to activate muscle stem cells (satellite cells) have been proposed. The majority of mtDNA defects are heteroplasmic (a mixture of mutated and wild-type mtDNA present within the muscle) with high levels of mutated mtDNA and low levels of wild-type mtDNA associated with more severe disease. The culture of satellite cell-derived myoblasts often reveals no evidence of the original mtDNA mutation although it is not known if this is lost by selection or simply not present in these cells. We have explored if the mtDNA mutation is present in the satellite cells in one of the commonest genotypes associated with mitochondrial myopathies (patients with single, large-scale mtDNA deletions). Analysis of satellite cells from eight patients showed that the level of mtDNA mutation in the satellite cells is the same as in the mature muscle but is most often subsequently lost during culture. We show that there are two periods of selection against the mutated form, one early on possibly during satellite cell activation and the other during the rapid replication phase of myoblast culture. Our data suggest that the mutations are also lost during rapid replication in vivo, implying that strategies to activate satellite cells remain a viable treatment for mitochondrial myopathies in specific patient groups.
منابع مشابه
Role of Mitochondria in Ataxia-Telangiectasia: Investigation of Mitochondrial Deletions and Haplogroups
Ataxia-Telangiectasia (AT) is a rare human neurodegenerative autosomal recessive multisystem disease that is characterized by a wide range of features including, progressive cerebellar ataxia with onset during infancy, occulocutaneous telangiectasia, susceptibility to neoplasia, occulomotor disturbances, chromosomal instability and growth and developmental abnormalities. Mitochondrial DNA (mtDN...
متن کاملResistance training in patients with single, large-scale deletions of mitochondrial DNA.
Dramatic tissue variation in mitochondrial heteroplasmy has been found to exist in patients with sporadic mitochondrial DNA (mtDNA) mutations. Despite high abundance in mature skeletal muscle, levels of the causative mutation are low or undetectable in satellite cells. The activation of these typically quiescent mitotic cells and subsequent shifting of wild-type mtDNA templates to mature muscle...
متن کاملMitochondrial Myopathy: a New Therapeutic Approach.
Restoration of deoxyribonucleic acid in mitochondrial myopathies may occur after a mechanical or chemical injury of striated muscle or by endurance training. Therapies with enzymes, gene therapies, or treatments with substances that stimulate mitochondrial biogenesis are used at the moment. Genesis of mitochondria may also come from myonuclei by releasing the nuclear respiratory factor-1/2 duri...
متن کاملComplete restoration of a wild-type mtDNA genotype in regenerating muscle fibres in a patient with a tRNA point mutation and mitochondrial encephalomyopathy.
Replicative segregation of mitochondrial DNA (mtDNA) can produce large differences in the proportions of wild-type and mutant mtDNAs in different cell types of patients with mitochondrial encephalomyopathy. This is particularly striking in the skeletal muscle of patients with Kearns-Sayre syndrome (KSS), a sporadic disease associated with large-scale mtDNA deletions, and in sporadic patients wi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 22 شماره
صفحات -
تاریخ انتشار 2013