Have you ever been scared of grey hair, skin wrinkles, baldness, or even worse, dementia? Voltaire once remarked, “What most persons consider as virtue, after the age of 40 is simply a loss of energy”. Nothing is as unnerving as the fact that we all have limited time on this beautiful planet. For centuries, humans have searched for the Philosopher’s Stone in order to achieve eternal life and vitality. Anti-aging products have become one of the most sought-after substances, not just in the glamour world, but among ordinary people.
Aging is a slow, natural, and irreversible process associated with changes in biological, physiological, psychological and social processes. While greying hair or wrinkles are some of the visible, rather benign consequences of aging, the more serious ones are declines in sensory functions and daily activities, as well as increased susceptibility to disease, frailty, or memory loss. Aging is by far the biggest contributor to death, killing more than two-thirds of the nearly 150,000 people that die every day across the globe.
The cause of such a complex phenomenon as aging is not completely understood. Among the plethora of theories proposed to explain it, perhaps the most well-known one is immunosenescence, which refers to the gradual decline in immunity. The immune system plays a critical role in maintaining our health as it protects us from infections and disease. As age naturally advances, a person’s capacity to respond to infections and develop long-term immune memory, especially by vaccination, decline considerably. The thymus is an important organ of the immune system, where T cells mature. As a person becomes older, the thymus shrinks in size and the production of T cells is reduced. The diminished function of mature lymphocytes, such as B cells and T cells weakens immunity. Macrophages, which ingest foreign cells, and destroy bacteria, cancer cells and other antigens, are created more slowly as age advances. This slowdown may be one reason behind cancer being more common among older people. Moreover, autoimmune disorders become more common with aging as the immune system appears to be less tolerant of the body’s own cells and normal tissue is mistaken for foreign tissue.
What’s the secret weapon to fight aging? Epigenetics seems to be the best bet to date. In particular, “DNA methylation”, a mechanism used by cells to control gene expression (i.e. whether, and when, a gene is turned on or off) plays a key role in age-related immunity, as discussed in this paper and elsewhere. Recently, researchers have successfully employed epigenetic reprogramming as a possible approach to preclude and reverse aging. Using middle-aged mice with a genetic mutation responsible for Hutchinson-Gilford progeria syndrome, which causes rapid aging in children, they activated four transcription factors known as “Yamanaka factors”. These factors can convert mature cells back into stem cells and were named after Japanese stem cell scientist Shinya Yamanaka, who won the Nobel Prize in Physiology or Medicine for discovering them. The approach rejuvenated damaged muscles and the pancreas, resulting in a 30% increase in life-span of the mice. Because the Yamanaka factors reversed changes made to gene regulators, this study adds weight to the scientific argument that aging is largely a process of epigenetic changes – alterations that dial gene activities up or down – including those that influence immunity.
Beyond waiting for the next scientific discovery, there are many proven ways seniors can strengthen their immune system and extend their life-span. Timely vaccinations, stress avoidance, meditation, good sleep and hygiene are few of them. Of course, in the words of director-actor Woody Allen, “You can live to be a hundred if you give up all things that make you want to live to be a hundred,” but with the current advancements in Genomics and Epigenetics, the day doesn’t seem too far when one might not need to give up guilty pleasures to live a long and healthy life.
To learn more about the association between aging and immune system, please be sure to attend the upcoming Athens Science Café on November 8, 2018. Dr. Nancy Manley, distinguished research professor and head of the Department of Genetics at UGA, will be sharing her perspective and expertise about this very interesting topic.
About the author:
|Debkanta Chakraborty is a Ph.D. Candidate in the Institute of Bioinformatics at the University of Georgia studying plant genetics and evolution. He has an interesting career arc, having pursued undergraduate studies in Electronics and Communication Engineering, a Masters in Biochemistry, and is now focusing on Genomics and Bioinformatics. Other than Biosciences, he is deeply passionate about Number Theory and Computational Geometry. In the leisure time which is a rarity in a graduate student’s life, he loves singing, playing an instrument called harmonium, participating in HQ trivia and watching movies. He hails from Durgapur, India and has an avid interest in traveling and watching tennis. He calls himself the biggest fan of Roger Federer. You can email him at firstname.lastname@example.org. More from Debkanta Chakraborty.|