Mitochondrial proteins that regulate longevity
"Humanin has long helped prevent many age-related diseases and this is the first time it has been shown to extend life," says Pinchas Cohen, the author of the study. The study examined homologous proteins in several animals, including nematodes and mice, and in humans, including those with Alzheimer's disease. The results highlight the potential of Humanin and other mitochondrial proteins as treatments for age-related diseases. They also suggest that anthropins may be an ancient mitochondrial signaling mechanism that is key to regulating human health and longevity, says lead author Kelvin Yen, assistant professor of research at USC.
In many species, declines in human protein levels have been previously observed with age.
In the new study, the scientists observed higher levels of human protein in organisms that tended to live longer. In contrast, mice experience a 40% drop in humanin during their first 18 months of life, and primates, such as rhesus monkeys, seem to have a staggering drop in humanin between the ages of 19 and 25.
"This trade-off between longevity and reproduction is thought to be due to an evolutionary conservative balance between using energy to produce more offspring or using energy to sustain an organism for future reproductive work," Yan said. In evolutionary terms, the goal of life is to reproduce, and then you're done, but if you can't reproduce, you should try to linger as long as possible, and the side effect of that is longevity." Higher human protein level is not only associated with longer service life; Lower levels may increase the risk of disease and reduce resistance to toxic exposure.
The researchers analyzed cerebrospinal fluid samples from a small number of alzheimer's patients and control individuals without dementia, and noted that human protein levels were much lower in Alzheimer's patients. In neonatal cord blood samples, high levels of human protein were associated with high mitochondrial DNA (mtDNA) copy Numbers, or the number of copies of the mitochondrial genome present in each cell.
"Human hemoglobin levels are inversely associated with reduced copy Numbers of mitochondrial DNA (mtDNA), which are themselves associated with many different diseases such as cancer, kidney disease and cardiovascular disease," Yan said. The extensive new study highlights the importance of Humanin as life and health, and USES it for treatment to address a variety of age-related diseases.