Understanding the Dynamics of the Aging Process
By: Sai Srihaas Potu
Why do we age? What exactly is happening in our bodies? And can we do anything about it? Mankind has sought answers to these questions for an exceptionally long time. Aging brings wisdom and respect, or so they say. But it also brings other less-desirable things like cognition decline, heart problems, or cancer, just to name a few. Aging is a complex process. Not everyone ages the same way, and it is influenced by a myriad of factors.
For centuries, scientists have been questioning this natural step of life, developing dietary approaches or new drugs with the hope of beating the clock on our lifespan. Aging is defined as the progressive accumulation of damage to your cells, tissues, and organs, leading to disease and death. According to one study, this dreadful process starts at 24 years of age, at least for the brain. According to others, it could be a bit later. Aging is associated with a decline in physical and cognitive health and is the main risk factor for many debilitating and life-threatening conditions including cardiovascular disease, cancer, and neurodegeneration.
Many researchers have spent years trying to answer the questions we have regarding the process of aging. While the pharmaceutical scientists Alexandra K. Kiemer and Jessica Hoppstädter from Saarland University are not claiming to have solved this ancient problem, they have uncovered processes within our immune system that contribute to aging. Kiemer and Hoppstädter have shown that low levels of the hormone cortisol and the protein known as GILZ can trigger chronic inflammatory responses in the body.
The phenomenon of human aging is the result of a complex interaction between numerous factors, with our immune system playing a critical role. As we get older, our body’s own defense mechanisms age, too. The adaptive or specific immune system that protects us from the pathogens that we come into contact with gradually deteriorates as we age. In contrast, however, our innate or non-specific immune system, which is the first line of defense towards a wide variety of pathogens, becomes overactive. The result is chronic inflammation.
A persistent state of inflammation can cause serious damage to our bodies. One consequence is that chronic inflammatory diseases, such as atherosclerosis or arthritis, are far more prevalent in older patients. ‘This has been well-known for a long time. In fact, the scientific community refers to this phenomenon as “inflamm-aging” – a portmanteau word that combines the two inseparably linked processes of inflammation and aging,’ explains Alexandra K. Kiemer, Professor of Pharmaceutical Biology at Saarland University.
What was uncertain up until now was what caused these inflammatory responses to flare up. Kiemer and her research group have now provided some important insight. According to research results from Jessica Hoppstädter, a lead researcher in Kiemer’s team, the inflammatory process is linked to the fact that the amount of cortisol generated in the body decreases as we get older.
Cortisol and its inactive form cortisone commonly referred to as stress hormones are released by the adrenal gland. The hormone cortisol acts as a biochemical signaling molecule and is involved in numerous metabolic processes in the body. Cortisol deficiency in the body leads to an inflammatory response. ‘The serum level of cortisol in the body is lower in the elderly. Moreover, macrophages, an important type of immune cells, can convert inactive cortisone to active cortisol, but this ability declines with increasing age. What we observe is what we could call “macroph-aging” – the age-induced disruption of macrophage functions,’ says Dr. Hoppstädter.
Macrophages are important cells within the immune system that use signaling molecules to control other immune cells. They play a critical role in determining the extent of our body’s inflammatory response. However, macrophage function becomes impaired with increasing age. This can lead to an increase in the quantities of pro-inflammatory signaling molecules, which in turn drives the activity of other inflammatory cells in the body’s immune system.
The studies conducted by the pharmaceutical research team in Saarbrücken indicate that one particular protein is implicated in the malfunctioning of macrophages in the elderly. The protein is known as GILZ and its levels are regulated in part by cortisol. ‘The acronym GILZ stands for glucocorticoid-induced leucine zipper,’ explains Professor Kiemer. Kiemer’s research group has been conducting experimental studies on the GILZ protein for many years and has discovered that it plays a critical role in many important processes in the human body. But GILZ can have a beneficial or a detrimental effect depending on the specific metabolic conditions.
Although significant progress has been achieved in characterizing aging-induced changes, research efforts should persist in this direction to develop innovative strategies based on recent achievements in the biology of aging to improve health-span. But if you can’t wait for new research, there are many DIY techniques available online that can help replenish your skin and make you look 20 years younger. So, get busy learning about the science of longevity, and you may just be able to beat the clock and live past 100.
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