Molecular Fountain Of Youth Discovered By University of California Researchers
A recent study published in the journal Cell Reports, in late January this year, reveals a major breakthrough in the understanding of aging and the molecular mechanisms involved in the process. This could be an important stepping stone for future therapy against degenerative diseases that affect the aging process of the patient. The research team from UCB (University of California, Berkeley) managed to reverse the molecular aging clock by infusing a longevity gene in the blood stem cells of aged laboratory mice. Their action caused the stem cells to regain their regenerative capabilities.
The research team found that a certain protein from the sirtuins class, SIRT3, is directly linked to the capabilities of aged stem cells to handle stress. Subsequently to the infusion of the stem cells with SIRT3, the research team observed the formation of new blood cells. This emphasizes the fact that the blood stem cells regained a part of their regenerative potential. “We already know that sirtuins regulate aging, but our study is really the first one demonstrating that sirtuins can reverse aging-associated degeneration”, reported assistant professor and main investigator of the study, Danica Chen. According to Chen, in the past couple of decades, scientists have made numerous breakthroughs towards the understanding of the aging process. Aging, once considered a random, uncontrolled process, is now known to be highly regulated.
Precedent studies have shown that as little as a single mutation in a gene can extend the lifespan of a patient. Dr Chen and her research team are investigating whether there is a possibility of reversing the aging process if the aging process is fully understood. The current study was conducted in collaboration with the director of the Center for Regenerative Medicine from the Massachusetts General Hospital. During the past few years, the class of proteins known as sirtuins, has become known to be closely related to the aging process. The most notable protein involved, SIRT3, can be found in the mitochondria of cells. The mitochondria are responsible for the generation of cellular energy, signaling, cellular differentiation and cell death, whilst also playing an important role in the cellular cycle and growth.
According to the research team, SIRT3 becomes active during calorie restriction. In order to determine the effects of aging on the organism, the research team investigated the functionality of adult stem cells. These cells start to lose their function with aging. Their main focus was on the hematopoietic stem cells (responsible of blood cells), due to the fact that these cells are capable to completely restore all the blood cells after a successful bone marrow transplant. All research was done on laboratory mice. The research team notes that the absence of SIRT3 in young laboratory mice had no impact on their blood systems. However, with the passing of time and the aging of the mice, the results changed. Tests conducted on 2-year old mice show that the ones where SIRT3 was absent had a lower level of stem cells than the normal mice. Researchers also observed that the regeneration capabilities of the remaining blood stem cells had declined.
Apparently, younger mice weren’t affected by the lack of SIRT3 due to the fact that there is only a small level of oxidative stress in their cells. “When we get older, our system doesn’t work as well, and we either generate more oxidative stress or we can’t remove it as well, so levels build up” reported Chen. Due to this fact, the antioxidative system can no longer cope with the accumulation of oxidative stress, thus needing the help of SIRT3 protein to. Nonetheless, the levels of SIRT3 also decrease with age. In order to see if higher levels of SIRT3 make a difference, scientist injected the mice with SIRT3. According to their report, this experiment managed to rejuvenate the precursors of the blood cells, which further led to an increased production rate of cells.
Further research is needed in order to see if SIRT3 is also capable to extend the lifespan. However, Chen notes that this was not the goal of their study. Researchers concluded that knowing how SIRT3 is involved in the genetic regulation of the aging process could lead to the possibility of new therapies being developed in order to treat age-related disorders such as cardiovascular disease, arthritis, osteoporosis, Alzheimer’s disease, cancer and others.