Humanin expression in skeletal muscles of patients with chronic progressive external ophthalmoplegia.

Abstract

We showed that humanin (HN), an endogenous peptide against Alzheimer disease-related insults, was expressed in muscles of patients with chronic progressive external ophthalmoplegia (CPEO), a major mitochondrial disease. Because HN was recently found to block proapoptotic Bax function and exert its versatile cytoprotective effects in association with an increase in ATP levels, HN expression may thus reflect a physiological response against degenerative changes in the muscles of patients with CPEO. We found HN expression in all four patients examined, each of whom had different mitochondrial DNA mutations including two different single DNA deletions, multiple deletions, and no major mutations detected. We also found that HN expression was not linked to focal cytochrome c deficiency, strongly associated with the subtype of CPEO with single deletions. These results suggest that HN expression is more closely related to degenerative changes in all types of CPEO. Notably, HN was also expressed in non-degenerative muscle fibers of patients with CPEO or Leigh syndrome, who had the 8993T>G mutation in the mitochondrial ATPase 6 gene known to be associated with impaired ATP synthesis. Collectively, our findings suggest that HN may be specifically expressed in response to defects in energy production in muscles with mitochondrial abnormalities.

• Authors: Tesseki Kin, Kazuma Sugie, Makito Hirano, Yu-Ichi Goto, Ichizo Nishino, Satoshi Ueno
• Journal: Journal of human genetics (J Hum Genet) Vol. 51 Issue 6 Pg. 555-558 ( 2006) ISSN: 1434-5161 [Print] England
• PMID: 16639504 (Publication Type: Journal Article)

Chemical References

• DNA, Mitochondrial
• Intracellular Signaling Peptides and Proteins
• Oxidative Phosphorylation Coupling Factors
• humanin
• Cytochromes c
• F(6) ATPase
• Mitochondrial Proton-Translocating ATPases

Topics

• Adolescent
• Child
• Child, Preschool
• Cytochromes c (deficiency)
• DNA, Mitochondrial (genetics)
• Female
• Gene Expression
• Humans
• Infant
• Intracellular Signaling Peptides and Proteins (genetics)
• Leigh Disease (genetics, metabolism)
• Male
• Middle Aged
• Mitochondrial Proton-Translocating ATPases (genetics)
• Muscle, Skeletal (metabolism)
• Ophthalmoplegia, Chronic Progressive External (genetics, metabolism)
• Oxidative Phosphorylation Coupling Factors (genetics)
• Point Mutation
• Sequence Deletion