Is “Gray Hair” caused by Stress?
Most of us know that all that comes with age is those visible Grey hair. But the fact we don,t know is that one more factor other than age are responsible for those stubborn Grey hair. They are caused by undue stress but this stress has effect on the cellular level. Geno toxic stress is a type of stress that damages the DNA. It results in sets off a chain of events, which has its harmful effect on specialized cells known as Melanocyte stem cells(MSCs). These cells are damaged and result in dis functioning within cells which are responsible for our hair color.
Research conducted by several scientist proved that the type of Geno toxic stress, which are responsible for the damage of our DNA causes the depletion of the MSCs in the hair follicle, that make the pigment producing melanocytes. When these cells are exposed to excessive stress the MSCs differentiate into melanocytes themselves, rather than just dying off. Hence, Researchers say that if we can limit the Geno toxic stress, we might stop graying of the hair.
A top scientist from the Tokyo Medical and Dental University, said,” The DnA in a cell in under constant attack by Exogenously and endogenously arising DNA damaging agents such as mutagenic chemicals, ultraviolet light, and ionizing radiation. It is estimated that a single cell in mammals can encounter approximately 100,000 DNA damaging events per day.” However, these specific cells have different ways to repair the damaged DNA and thus prevents this damages to be passed to other daughter cells.
Nishimura explained, “Once stem cells are damaged irreversibly, the damaged stem cells need to be eliminated to maintain the quality of the stem cell pools. We found that excessive Geno toxic stress triggers differentiation of melanocyte stem cells.”she also explained that the differentiation may be a more complex way to eliminate those cells all together instead of fostering their death.
Previously, Nishimura’s team had done research to trace the hair color loss to gradual loss of the stem cells, which are used to maintain a continuous supply of melanocytes, which gives our hair youthful, shiny color. It was found that, the specialized sem cells are not only lost, but they differentiate into fully committed pigment cells that are not in there proper place.
Recent study, conducted on mice, proved that irreparable DNA damage, that was caused by ionizing radiation, is responsible. The Researchers also found that the caretaker gene which is also known as ATM (ataxia telangiectasia) acts as a stemness checkpoint that helps protection against differentiation of MSCs. That’s the reason why the people who suffer from Ataxia telangiectasia, which is a syndrome in which aging happens prematurely, is caused by an ATM gene mutation, results in premature graying of hair.
The latest research proves that genome instability play as important role in aging. It also forms a basis for stem cell aging hypothesis, which states that DNA damaged to long lived stem cells can be a major driver for several conditions that develop as we age.
Other than stem cell depletion which is associated with typical aging found in MSCs,qualitative and quantitative alterations to the blood stem cells, skeletal muscle and cardiac muscle have been seen. Genome maintenance failures and the stresses on stem cell pools are also considered to be responsible for the reduction of the tissue renewal capacity and the accelerated appearance of aging-related characteristics, such as the graying of hair.
The team told, “In this study, we discovered that hair graying, the most obvious aging phenotype, can be caused by the genomic damage response through stem cell differentiation, which suggests that physiological hair graying can be triggered by the accumulation of unavoidable DNA damage and DNA-damage response associated with aging through MSC differentiation.”
