Here, we used mice with skeletal-muscle-specific disruption of the nuclear gene for mitochondrial transcription factor A (Tfam) to study whether changes in cellular Ca(2+) handling is part of the mechanism of muscle dysfunction in mitochondrial myopathy.
Furthermore, processed OPA1 was observed in heart tissue derived from heart-specific TFAM knock-out mice suffering from mitochondrial cardiomyopathy and in skeletal muscles from patients suffering from mitochondrial myopathies such as myopathy encephalopathy lactic acidosis and stroke-like episodes.
Low levels of mitochondrial transcription factor A (mtTFA) were found in muscle fibers with mitochondrial DNA (mtDNA) depletion in a child with fatal mitochondrial myopathy and also in a human cell line lacking mtDNA.